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Sample records for attenuated total reflectance

  1. Dispersion effects on infrared spectra in attenuated total reflection

    Science.gov (United States)

    Belali, Rabah; Vigoureux, Jean-Marie; Morvan, Joseph

    1995-12-01

    A potential problem with the attenuated total reflection that is used to measure infrared spectra is described. The problem is the possibility that the anomalous dispersion associated with an infrared absorption band may cause the experimental configuration to move from the attenuated total reflection regime to the specular reflection regime, with consequent distortion of the apparent absorption bands and consequent error in the interpretation of the bands if the problem is not recognized. Key infrared spectra, attenuated total reflection, specular reflection, polyethylene terephtalate. Copyright (c) 1995 Optical Society of America

  2. Relationship between normalized light intensity and attenuated total reflection ratio

    Institute of Scientific and Technical Information of China (English)

    Yingcai Wu; Zhengtian Gu

    2008-01-01

    Attenuated total reflection (ATR) ratio is usually utilized to study the properties of surface plasmon resonance (SPR) sensors. The relationship between normalized light intensity and ATR ratio is investigated, and a modification coefficient is put forward to describe the relationship. A mathematical expression is built up for the coefficient based on Fresnel principle. The result shows that the ATR ratio, which cannot be measured directly in experiments, can be determined with the coefficient and the normalized intensity of light. The characteristic of the coefficient is also discussed.

  3. Metamaterial radiation from attenuated total reflection at terahertz frequencies

    Science.gov (United States)

    Ramani, Suchitra

    The focus of this research was to explore the behavior of two-dimensional planar metamaterials or metafilms and understand the various excitation schemes for application of metafilms to Terahertz-Attenuated Total Reflection spectroscopy (THz-ATR). A standard THz time domain spectroscopy system based on photoconductive switches was modified to implement the ATR technique. Finite metamaterial arrays with varying singly- split ring resonator sizes were excited in the Kretschmann ATR configuration using finite sized terahertz beams. Numerical approaches using commercial software were looked into to explain the experimental observations. Various theoretical models were used to explain the observed phenomena. The ATR measurements showed an unexpected strengthening of the resonance when the metafilm sample was illuminated near the edge. This phenomenon referred to in this study as "the anomalous edge enhancement" was observed strongly in metafilms with closely spaced rings. A re-radiation signal was observed across the total internal reflection barrier where no signal is expected. It consisted of two peaks one at the fundamental metamaterial resonance and the second peak was due to the periodicity of the metafilm array. The anomalous behavior seen in the ATR measurements is attributed to the edge currents at the boundary of the metafilm array giving rise to this re-radiation signal. Results from analytic treatments based on Floquet method and method of moments were able to qualitatively model the measurements. The observed re-radiation signal is a potential loss mechanism that could impact observations from commonly used transmission measurements on metamaterials.

  4. Infrared analysis of thin layers by attenuated total reflection spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rochat, N.; Chabli, A.; Bertin, F.; Vergnaud, C.; Mur, P.; Petitdidier, S.; Besson, P

    2003-09-15

    Interests in infrared spectroscopy (IRS) have been stimulated by the increasing need for non-destructive surface characterization providing structural and chemical informations about the new materials used in microelectronic devices. Standard infrared spectroscopy of thin layers is limited because of its lack of sensitivity. The use of optical configurations such as the attenuated total reflection (ATR) allows to characterize nanometric layers. This paper will present the results of a study conducted for a better understanding of the capabilities and limitations of this technique. A theoretical analysis based on a perturbation method is used to elucidate the results of ATR measurements performed on silicon oxide layers of different thickness on silicon substrates. This analysis shows that the absorbance ATR spectrum in p polarization is the image of the layer energy loss function, under specific conditions. The exact ATR spectrum simulation using a matrix formalism showed that the straightforward interpretation in terms of the layer dielectric function is limited to a very narrow layer thickness range. The fitting process of the ATR spectrum is evaluated for the interpretation of experimental spectra obtained for the growth of chemical silicon oxide layers.

  5. Monitoring the catalytic synthesis of glycerol carbonate by real-time attenuated total reflection FTIR spectroscopy

    NARCIS (Netherlands)

    Calvino-Casilda, V.; Mul, G.; Fernandez, J.F.; Rubio-Marcos, F.; Banares, M.A.

    2011-01-01

    In situ Attenuated Total Reflectance FTIR spectroscopy was used to study the carbonylation of glycerol with urea. Cobalt oxide nanoparticles, Co3O4, hierarchically dispersed on zinc oxide microparticles, ZnO, were used as catalysts. The present work demonstrates that in situ real-time attenuated tot

  6. Orientation of melittin in phospholipid bilayers. A polarized attenuated total reflection infrared study.

    OpenAIRE

    Frey, S.; Tamm, L K

    1991-01-01

    The helical order parameter of the 26-residue amphiphilic bee venom peptide melittin was measured by polarized attenuated total reflection infrared spectroscopy (ATR-IR) in dry phospholipid multibilayers (MBLs) and when bound to single supported planar bilayers (SPBs) under D2O. Melittin adopted an alpha-helical conformation in MBLs of dipalmitoyl-phosphatidylcholine (DPPC), 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC), a 4:1 mixture of POPC and 1-palmitoyl-2-oleoyl-phosphatidylglycerol (P...

  7. Local temperature variation measurement by anti-Stokes luminescence in attenuated total reflection geometry.

    Science.gov (United States)

    Yamamoto, Ken; Togawa, Ryotaro; Fujimura, Ryushi; Kajikawa, Kotaro

    2016-08-22

    Strong temperature dependence of anti-Stokes luminescence intensity from Rhodamine 101 is used to probe local temperature variation at a surface region in the attenuated total reflection geometry (ATR), when heating with laser light. In this method, the measured region can be limited by observing evanescent luminescence. The near-field depth (penetration depth) was changed by the observation angle θout of the evanescent luminescence and the spatial temperature variation was observed. PMID:27557182

  8. An effective medium study of surface plasmon polaritons in nanostructured gratings using attenuated total reflection

    Energy Technology Data Exchange (ETDEWEB)

    Tyboroski, M. H.; Anderson, N. R.; Camley, R. E. [UCCS BioFrontiers Center, University of Colorado at Colorado Springs, Colorado Springs, Colorado 80918 (United States)

    2014-01-07

    Recent work studied surface plasmon resonances in structured materials by the method of attenuated total reflection using a prism on top of a metallic grating. That calculation considered Transverse Magnetic polarized radiation, involved an expansion in 121 Fourier modes, and found a number of interesting features. Many of these features were attributed to localized plasmons or other factors, which arise from a discrete structure. We use a simple effective medium theory to address the same problem, and find many of the same reflection features observed in the more complex calculation, indicating that localization is not an important factor. We also evaluate the possibility of using some of the new features in the reflection spectrum for bio-sensing and find that the sensitivity of the system to small changes in relative permittivity is increased compared to some standard methods.

  9. Anisotropy in Thermo-Optic Coefficient of Different Polymer Systems by Attenuated Total Reflection Configuration

    Institute of Scientific and Technical Information of China (English)

    LI Xiang; CAO Zhuang-Qi; SHEN Qi-Shun; MENG Qing-Hua; HUANG De-Ying; GUO Kun-Peng; QIU Ling; SHEN Yu-Quan

    2006-01-01

    @@ Thermo-optic coefficient dn/dT as well as volume expansion coefficients β of different polymer systems are measured for both TE and TM polarizations in an attenuated total reflection (ATR) configuration. Experimental results indicate that cross-linked polymer systems exhibit the thermal expansion coefficients smaller than those of the original side-chain systems. Moreover, the anisotropies in thermo-optic coefficients of the polymer systems with small birefringence exhibit linear relationship with the anisotropies in volume expansion coefficients, but the polymer systems with larger birefringence exhibit more complicated relationship.

  10. [Rapid quantitative analysis of hydrocarbon composition of furfural extract oils using attenuated total reflection infrared spectroscopy].

    Science.gov (United States)

    Li, Na; Yuan, Hong-Fu; Hu, Ai-Qin; Liu, Wei; Song, Chun-Feng; Li, Xiao-Yu; Song, Yi-Chang; He, Qi-Jun; Liu, Sha; Xu, Xiao-Xuan

    2014-07-01

    A set of rapid analysis system for hydrocarbon composition of heavy oils was designed using attenuated total reflection FTIR spectrometer and chemometrics to determine the hydrocarbon composition of furfural extract oils. Sixty two extract oil samples were collected and their saturates and aromatics content data were determined according to the standard NB/SH/T0509-2010, then the total contents of resins plus asphaltenes were calculated by the subtraction method in the percentage of weight. Based on the partial least squares (PLS), calibration models for saturates, aromatics, and resin+asphaltene contents were established using attenuated total reflection FTIR spectroscopy, with their SEC, 1.43%, 0.91% and 1.61%, SEP, 1.56%, 1.24% and 1.81%, respectively, meeting the accuracy and repeatability required for the standard. Compared to the present standard method, the efficiency of hydrocarbon composition analysis for furfural extract oils is significantly improved by the new method which is rapid and simple. The system could also be used for other heavy oil analysis, with excellent extension and application foreground.

  11. Modeling the attenuated total reflectance infrared (ATR-FTIR) spectrum of apatite

    Science.gov (United States)

    Aufort, Julie; Ségalen, Loïc; Gervais, Christel; Brouder, Christian; Balan, Etienne

    2016-06-01

    Attenuated total reflectance (ATR) infrared spectra were measured on a synthetic and a natural fluorapatite sample. A modeling approach based on the computation of the Fresnel reflection coefficient between the ATR crystal and the powder sample was used to analyze the line shape of the spectra. The dielectric properties of the samples were related to those of pure fluorapatite using an effective medium approach, based on Maxwell-Garnett and Bruggeman models. The Bruggeman effective medium model leads to a very good agreement with the experimental data recorded on the synthetic fluorapatite sample. The poorer agreement observed on the natural sample suggests a more significant heterogeneity of the sample at a characteristic length scale larger than the mid-infrared characteristic wavelength, i.e., about 10 micrometers. The results demonstrate the prominent role of macroscopic electrostatic effects over fine details of the microscopic structure in determining the line shape of strong ATR bands.

  12. Detection of whitening agents in illegal cosmetics using attenuated total reflectance-infrared spectroscopy.

    Science.gov (United States)

    Deconinck, E; Bothy, J L; Desmedt, B; Courselle, P; De Beer, J O

    2014-09-01

    Cosmetic products containing illegal whitening agents are still found on the European market. They represent a considerable risk to public health, since they are often characterised by severe side effects when used chronically. The detection of such products at customs is not always simple, due to misleading packaging and the existence of products containing only legal components. Therefore there is a need for easy to use equipment and techniques to perform an initial screening of samples. The use of attenuated total reflectance-infrared (ATR-IR) spectroscopy, combined with chemometrics, was evaluated for that purpose. It was found that the combination of ATR-IR with the simple chemometric technique k-nearest neighbours gave good results. A model was obtained in which a minimum of illegal samples was categorised as legal. The correctly classified illegal samples could be attributed to the illegal components present. PMID:24927403

  13. In situ probing of surface hydrides on hydrogenated amorphous silicon using attenuated total reflection infrared spectroscopy

    CERN Document Server

    Kessels, W M M; Sanden, M C M; Aydil, E S

    2002-01-01

    An in situ method based on attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) is presented for detecting surface silicon hydrides on plasma deposited hydrogenated amorphous silicon (a-Si:H) films and for determining their surface concentrations. Surface silicon hydrides are desorbed by exposing the a-Si:H films to low energy ions from a low density Ar plasma and by comparing the infrared spectrum before and after this low energy ion bombardment, the absorptions by surface hydrides can sensitively be separated from absorptions by bulk hydrides incorporated into the film. An experimental comparison with other methods that utilize isotope exchange of the surface hydrogen with deuterium showed good agreement and the advantages and disadvantages of the different methods are discussed. Furthermore, the determination of the composition of the surface hydrogen bondings on the basis of the literature data on hydrogenated crystalline silicon surfaces is presented, and quantification of the h...

  14. Polarized infrared attenuated total reflection study of sapphire crystals with different crystallographic planes

    Science.gov (United States)

    Lee, S. C.; Ng, S. S.; Hassan, H. Abu; Dumelow, T.

    2015-04-01

    Polarized infrared (IR) attenuated total reflection (ATR) measurements were performed on c- (polar) and r-plane (semi-polar) sapphire crystals. For c-plane sapphire crystal, spectral features due to the surface phonon polariton (SPhP) modes are only observable in the p-polarized ATR spectrum. Calculation of the SPhP dispersion spectra revealed that the SPhP modes of r-plane sapphire crystal are possible to be observed in both the s- and p-polarized ATR spectra. ATR measurements verified that excitation of the SPhP modes are still easier in the p-polarized ATR spectra. Taking into account the effects of anisotropy and the crystal orientation of hexagonal crystal system, the ATR spectra of r-plane sapphire crystal with arbitrary orientations were simulated. Through a best fit of experimental with simulated spectra, information about the crystal orientation of sapphire crystals was deduced.

  15. Detection of whitening agents in illegal cosmetics using attenuated total reflectance-infrared spectroscopy.

    Science.gov (United States)

    Deconinck, E; Bothy, J L; Desmedt, B; Courselle, P; De Beer, J O

    2014-09-01

    Cosmetic products containing illegal whitening agents are still found on the European market. They represent a considerable risk to public health, since they are often characterised by severe side effects when used chronically. The detection of such products at customs is not always simple, due to misleading packaging and the existence of products containing only legal components. Therefore there is a need for easy to use equipment and techniques to perform an initial screening of samples. The use of attenuated total reflectance-infrared (ATR-IR) spectroscopy, combined with chemometrics, was evaluated for that purpose. It was found that the combination of ATR-IR with the simple chemometric technique k-nearest neighbours gave good results. A model was obtained in which a minimum of illegal samples was categorised as legal. The correctly classified illegal samples could be attributed to the illegal components present.

  16. Unidirectional excitation of graphene plasmon in attenuated total reflection (ATR) configuration

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Wei [Hubei University of Education, Wuhan (China). School of Physics and Mechanical and Electrical Engineering; Wu, Yue-Chao [Nanyang Technological University, Singapore (Singapore). Div. of Physics and Applied Physics; Liu, Fang-Li [Maryland Univ., College Park, MD (United States). Joint Quantum Institute

    2016-08-01

    Graphene plasmon has been attracting interests from both theoretical and experimental research due to its gate tunability and potential applications in the terahertz frequency range. Here, we propose an effective scheme to unidirectionally excite the graphene plasmon by exploiting magneto-optical materials in the famous attenuated total reflection (ATR) configuration. We show that the graphene plasmon dispersion relation in such a device is asymmetric in different exciting directions, thus making it possible to couple the incident light unidirectionally to the propagating plasmon. The split of absorption spectrum of graphene clearly indicates that under a magnetic field for one single frequency, graphene plasmon can only be excited in one direction. The possible gate tunablity of excitation direction and the further application of the proposed scheme, such as optical isolator, also are discussed.

  17. Discrimination of nylon polymers using attenuated total reflection mid-infrared spectra and multivariate statistical techniques.

    Science.gov (United States)

    Enlow, Elizabeth M; Kennedy, Jennifer L; Nieuwland, Alexander A; Hendrix, James E; Morgan, Stephen L

    2005-08-01

    Nylons are an important class of synthetic polymers, from an industrial, as well as forensic, perspective. A spectroscopic method, such as Fourier transform infrared (FT-IR) spectroscopy, is necessary to determine the nylon subclasses (e. g., nylon 6 or nylon 6,6). Library searching using absolute difference and absolute derivative difference algorithms gives inconsistent results for identifying nylon subclasses. The objective of this study was to evaluate the usefulness of peak ratio analysis and multivariate statistics for the identification of nylon subclasses using attenuated total reflection (ATR) spectral data. Many nylon subclasses could not be distinguished by the peak ratio of the N-H vibrational stretch to the sp(3) C-H(2) vibrational stretch intensities. Linear discriminant analysis, however, provided a graphical visualization of differences between nylon subclasses and was able to correctly classify a set of 270 spectra from eight different subclasses with 98.5% cross-validated accuracy.

  18. Simulation of attenuated total reflection infrared absorbance spectra: applications to automotive clear coat forensic analysis.

    Science.gov (United States)

    Lavine, Barry K; Fasasi, Ayuba; Mirjankar, Nikhil; Nishikida, Koichi; Campbell, Jay

    2014-01-01

    Attenuated total reflection (ATR) is a widely used sampling technique in infrared (IR) spectroscopy because minimal sample preparation is required. Since the penetration depth of the ATR analysis beam is quite shallow, the outer layers of a laminate or multilayered paint sample can be preferentially analyzed with the entire sample intact. For this reason, forensic laboratories are taking advantage of ATR to collect IR spectra of automotive paint systems that may consist of three or more layers. However, the IR spectrum of a paint sample obtained by ATR will exhibit distortions, e.g., band broadening and lower relative intensities at higher wavenumbers, compared with its transmission counterpart. This hinders library searching because most library spectra are measured in transmission mode. Furthermore, the angle of incidence for the internal reflection element, the refractive index of the clear coat, and surface contamination due to inorganic contaminants can profoundly influence the quality of the ATR spectrum obtained for automotive paints. A correction algorithm to allow ATR spectra to be searched using IR transmission spectra of the paint data query (PDQ) automotive database is presented. The proposed correction algorithm to convert transmission spectra from the PDQ library to ATR spectra is able to address distortion issues such as the relative intensities and broadening of the bands, and the introduction of wavelength shifts at lower frequencies, which prevent library searching of ATR spectra using archived IR transmission data. PMID:25014606

  19. Numerical studies of surface and bulk modes in attenuated total reflection spectra

    Institute of Scientific and Technical Information of China (English)

    Yan Bao-Rong; Lü Jian-Hong; Kong Ling-Hua; Hu Xi-Wei

    2011-01-01

    The dispersion relations of normal modes in the layered constructions are studied. In the frequency region with negative permittivity, we investigate the normal modes near the air-metal and the air-matematerial interfaces and compare them. An extra bulk mode appearing in a pass band of two media is found near the air-matematerial interface,which is different from the air-metal case. Moreover, the bulk mode will be further proved by the attenuated total reflection (ATR) technique, in which the coupling between the incident electromagnetic waves and the normal modes is studied. For p-polarized incident waves, the ATR spectra based on the Otto and the Kretschmann configurations are obtained numerically, where the dips present the excitations of the surface and bulk modes. Furthermore, we also discuss the influences of the middle layer thickness, the incident angle and the damping term on the reflection in detail. It is found that the coupling frequencies and the maximum strength are strongly dependent on the above media parameters.

  20. Characterization of Printing Inks Using DART-Q-TOF-MS and Attenuated Total Reflectance (ATR) FTIR.

    Science.gov (United States)

    Williamson, Rhett; Raeva, Anna; Almirall, Jose R

    2016-05-01

    The rise in improved and widely accessible printing technology has resulted in an interest to develop rapid and minimally destructive chemical analytical techniques that can characterize printing inks for forensic document analysis. Chemical characterization of printing inks allows for both discrimination of inks originating from different sources and the association of inks originating from the same source. Direct analysis in real-time mass spectrometry (DART-MS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were used in tandem to analyze four different classes of printing inks: inkjets, toners, offset, and intaglio. A total of 319 samples or ~ 80 samples from each class were analyzed directly on a paper substrate using the two methods. DART-MS was found to characterize the semi-volatile polymeric vehicle components, while ATR-FTIR provided chemical information associated with the bulk components of these inks. Complimentary data results in improved discrimination when both techniques are used in succession resulting in >96% discrimination for all toners, 95% for all inkjets, >92% for all offset, and >54% for all intaglio inks. PMID:27122410

  1. Attenuated total reflectance fourier transform infrared analysis of fly ash geopolymer gel aging.

    Science.gov (United States)

    Rees, Catherine A; Provis, John L; Lukey, Grant C; van Deventer, Jannie S J

    2007-07-17

    Structural changes in fly ash geopolymers activated with different sodium hydroxide and silicate concentrations are investigated using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy over a period of 200 days. A strong correlation is found between the concentration of silicate monomer in the activating solution and the position of the main Si-O-T stretching band in the FTIR spectrum, which gives an indication of the relative changes in the gel Si/Al ratio. The FTIR spectra of geopolymer samples with activating solution concentrations of up to 1.2 M SiO2 indicate that an Al-rich gel forms before the final gel composition is reached. The time required for the system to reach a steady gel composition depends on the silicate activating solution concentration and speciation. Geopolymers activated with solutions containing predominantly high-order silicate species rapidly reach a steady gel composition without first forming an Al-rich gel. A minimum silicate monomer concentration of approximately 0.6 M is required to shift the geopolymer synthesis mechanism from hydroxide activation to silicate activation. Silicate speciation in the activating solutions also affects zeolite formation and geopolymer microstructures, with a more homogeneous microstructure and less zeolite formation observed at a higher SiO2 content.

  2. Detection of sibutramine in adulterated dietary supplements using attenuated total reflectance-infrared spectroscopy.

    Science.gov (United States)

    Deconinck, E; Cauwenbergh, T; Bothy, J L; Custers, D; Courselle, P; De Beer, J O

    2014-11-01

    Sibutramine is one of the most occurring adulterants encountered in dietary supplements with slimming as indication. These adulterated dietary supplements often contain a herbal matrix. When customs intercept these kind of supplements it is almost impossible to discriminate between the legal products and the adulterated ones, due to misleading packaging. Therefore in most cases these products are confiscated and send to laboratories for analysis. This results inherently in the confiscation of legal, non-adulterated products. Therefore there is a need for easy to use equipment and techniques to perform an initial screening of samples. Attenuated total reflectance-infrared (ATR-IR) spectroscopy was evaluated for the detection of sibutramine in adulterated dietary supplements. Data interpretation was performed using different basic chemometric techniques. It was found that the use of ATR-IR combined with the k-Nearest Neighbours (k-NN) was able to detect all adulterated dietary supplements in an external test set and this with a minimum of false positive results. This means that a small amount of legal products will still be confiscated and analyzed in a laboratory to be found negative, but no adulterated samples will pass the initial ATR-IR screening. PMID:25173110

  3. [Discriminant Analysis of Lavender Essential Oil by Attenuated Total Reflectance Infrared Spectroscopy].

    Science.gov (United States)

    Tang, Jun; Wang, Qing; Tong, Hong; Liao, Xiang; Zhang, Zheng-fang

    2016-03-01

    This work aimed to use attenuated total reflectance Fourier transform infrared spectroscopy to identify the lavender essential oil by establishing a Lavender variety and quality analysis model. So, 96 samples were tested. For all samples, the raw spectra were pretreated as second derivative, and to determine the 1 750-900 cm(-1) wavelengths for pattern recognition analysis on the basis of the variance calculation. The results showed that principal component analysis (PCA) can basically discriminate lavender oil cultivar and the first three principal components mainly represent the ester, alcohol and terpenoid substances. When the orthogonal partial least-squares discriminant analysis (OPLS-DA) model was established, the 68 samples were used for the calibration set. Determination coefficients of OPLS-DA regression curve were 0.959 2, 0.976 4, and 0.958 8 respectively for three varieties of lavender essential oil. Three varieties of essential oil's the root mean square error of prediction (RMSEP) in validation set were 0.142 9, 0.127 3, and 0.124 9, respectively. The discriminant rate of calibration set and the prediction rate of validation set had reached 100%. The model has the very good recognition capability to detect the variety and quality of lavender essential oil. The result indicated that a model which provides a quick, intuitive and feasible method had been built to discriminate lavender oils. PMID:27400512

  4. Attenuated total reflectance Fourier transform infrared spectroscopy method to differentiate between normal and cancerous breast cells.

    Science.gov (United States)

    Lane, Randy; See, Seong S

    2012-09-01

    Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) is used to find the structural differences between cancerous breast cells (MCF-7 line) and normal breast cells (MCF-12F line). Gold nanoparticles were prepared and the hydrodynamic diameter of the gold nanoparticles found to be 38.45 nm. The Gold nanoparticles were exposed to both MCF-7 and MCF-12F cells from lower to higher concentrations. Spectroscopic studies founds nanoparticles were within the cells, and increasing the nanoparticles concentration inside the cells also resulted in sharper IR peaks as a result of localized surface Plasmon resonance. Asymmetric and symmetric stretching and bending vibrations between phosphate, COO-, CH2 groups were found to give negative shifts in wavenumbers and a decrease in peak intensities when going from noncancerous to cancerous cells. Cellular proteins produced peak assignments at the 1542 and 1644 cm(-1) wavenumbers which were attributed to the amide I and amide II bands of the polypeptide bond of proteins. Significant changes were found in the peak intensities between the cell lines in the spectrum range from 2854-2956 cm(-1). Results show that the concentration range of gold nanoparticles used in this research showed no significant changes in cell viability in either cell line. Therefore, we believe ATR-FTIR and gold nanotechnology can be at the forefront of cancer diagnosis for some time to come.

  5. Compositional features of cotton plant biomass fractions characterized by attenuated total reflection Fourier transform infrared spectroscopy

    Science.gov (United States)

    Cotton is one of the most important and widely grown crops in the world. In addition to natural textile fiber production as a primary purpose, it yields a high grade vegetable oil for human consumption and also carbohydrate fiber and protein byproducts for animal feed. In this work, attenuated total...

  6. Secondary cell wall development in cotton fibers as examined with attenuated total reflection Fourier transform infrared spectroscopy

    Science.gov (United States)

    Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-IR) spectroscopy. The selected harvesting points coincide with secondary cell wall (SCW) development in the fibers. Progressive but moderat...

  7. STUDY OF INK LAYER BY METHOD OF ATTENUATED TOTAL REFLECTANCE SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    D. G. Fatkhullina

    2016-05-01

    Full Text Available Subject of Research. Researchresults of thickness distribution of an ink layer smearedon a glass surface are presented. The orange ink which is used as a coloring pigment in writing instrument (highlighter is selectedasan object of study. Method. Researches were carried out by the method of attenuated total reflectance(ATR spectroscopy. The spectral setup fitted up on the basis of monochromator MDR-204 was usedin the experiment. The peculiarity of the measurement scheme is the applicationofhigh-resolution camera as a radiation detector and information storage as an images package. Researches allowed receivingexperimental data in the form of ink ATR spectra arrayfor studied areas of layer surface in a given spectral range. Main Results. The estimation of ink layer thickness was done, that gives the possibilityto visualize its distribution over the surface using three-dimensional modeling capabilities. The thickness of the ink layer is not more than 0.12 microns and arithmetic mean of the thickness is0.06 microns. The local areas are observed in an ink distribution, they have a maximum layer thickness (0.07-0.12 microns or areas with the ink thickness less then 0.03 microns. Variation of the ink layer thicknessbetween the local areas is smooth. Practical Relevance. The proposed measuring scheme, the sequence of registration and processing of experimental data can be used to studyink distribution within the thickness of a surface layer of other materials,for example, in analysis of signs performed by an ink on paper medium in order to identify them in such areas of science as forensic science andstudy of art.

  8. Metallic attenuated total reflection infrared hollow fibers for robust optical transmission systems

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Chengbin; Guo, Hong; Hu, Zhigao; Yang, Pingxiong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); Chu, Junhao [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai 200083 (China); Liu, Aiyun [Department of Physics, Shanghai Normal University, 100 Gui Lin Road, Shanghai 200234 (China); Shi, Yiwei [School of Information Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2014-07-07

    A durable metallic attenuated total reflection (ATR) hollow fiber (bore size: 1.45 mm, wall thickness: 50 μm) was designed and fabricated based on a nickel capillary tube and hexagonal germanium dioxide (GeO{sub 2}). The anomalous dispersion of the hexagonal GeO{sub 2} layer grown inside a nickel tube achieves low-loss light transmission at two peak-power wavelengths for CO{sub 2} laser devices (10.2 and 10.6 μm). An 11–28 W, 10.2 or 10.6 μm CO{sub 2} laser power was steadily delivered via a fiber elastically bent from 0° to 90° (radius: 45 cm) for over 40 min (transmission loss: 0.22 to 4.2 dB/m). Theoretically fitting the measured temperatures showed that front-end clipping caused greater thermal loading than the distributed mode absorption. The maximum external temperature of a nickel ATR fiber is much lower than that of a silica glass ATR fiber owing to their different heat dissipation abilities. The HE{sub 11} mode purity of the output beam profiles decreased from 90.3% to 44.7% as the bending angle increased from 0° to 90°. Large core sizes and wall roughnesses (scattering loss 0.04 dB/m) contributed to mode mixing and excess losses that were above the value predicted by the classical Marcatili and Schmeltzer equation (0.024–0.037 dB/m).

  9. Attenuated total reflection-Fourier transform infrared spectroscopic imaging of pharmaceuticals in microfluidic devices.

    Science.gov (United States)

    Ewing, Andrew V; Clarke, Graham S; Kazarian, Sergei G

    2016-03-01

    The poor aqueous solubility of many active pharmaceutical ingredients presents challenges for effective drug delivery. In this study, the combination of attenuated total reflection (ATR)-FTIR spectroscopic imaging with specifically designed polydimethylsiloxane microfluidic devices to study drug release from pharmaceutical formulations has been developed. First, the high-throughput analysis of the dissolution of micro-formulations studied under flowing conditions has been introduced using a model formulation of ibuprofen and polyethylene glycol. The behaviour and release of the drug was monitored in situ under different pH conditions. In contrast to the neutral solution, where both the drug and excipient dissolved at a similar rate, structural change from the molecularly dispersed to a crystalline form of ibuprofen was characterised in the obtained spectroscopic images and the corresponding ATR-FTIR spectra for the experiments carried out in the acidic medium. Further investigations into the behaviour of the drug after its release from formulations (i.e., dissolved drug) were also undertaken. Different solutions of sodium ibuprofen dissolved in a neutral medium were studied upon contact with acidic conditions. The phase transition from a dissolved species of sodium ibuprofen to the formation of solid crystalline ibuprofen was revealed in the microfluidic channels. This innovative approach could offer a promising platform for high-throughput analysis of a range of micro-formulations, which are of current interest due to the advent of 3D printed pharmaceutical and microparticulate delivery systems. Furthermore, the ability to study dissolved drug in solution under flowing conditions can be useful for the studies of the diffusion of drugs into tissues or live cells. PMID:27158293

  10. Tethered bilayer lipid membranes studied by simultaneous attenuated total reflectance infrared spectroscopy and electrochemical impedance spectroscopy

    Science.gov (United States)

    Erbe, Andreas; Bushby, Richard J.; Evans, Stephen D.; Jeuken, Lars J. C.

    2013-01-01

    The formation of tethered lipid bilayer membranes (tBLMs) from unilamelar vesicles of egg yolk phosphatidylcholine (EggPC) on mixed self–assembled monolayers (SAMs) from varying ratios of 6-mercaptohexanol and EO3Cholesteryl on gold has been monitored by simultaneous attenuated total reflectance fourier transform infrared (ATR–FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS). The influence of the lipid orientation (and hence the anisotropy) of lipids on a gold film on the dichroic ratio was studied by simulations of spectra with a matrix method for anisotropic layers. It is shown that for certain tilt angles of the dielectric tensor of the adsorbed anisotropic layer dispersive and negative absorption bands are possible. The experimental data indicates that the structure of the assemblies obtained varies with varying SAM composition. On SAMs with a high content of EO3Cholesteryl, tBLMs with reduced fluidity are formed. For SAMs with high content of 6-mercaptohexanol, the results are consistent with the adsorption of flattened vesicles, while spherical vesicles have been found in a small range of surface compositions. The kinetics of the adsorption process is consistent with the assumption of spherical vesicles as long–living intermediates for surfaces of high 6-mercaptohexanol content. No long–living spherical vesicles have been detected for surfaces with large fraction of EO3Cholesteryl tethers. The observed differences between the surfaces suggest that for the formation of tBLMs (unlike supported BLMs) no critical surface coverage of vesicles is needed prior to lipid bilayer formation. PMID:17388505

  11. Comparative study of Fourier transform infrared spectroscopy in transmission, attenuated total reflection, and total reflection modes for the analysis of plastics in the cultural heritage field.

    Science.gov (United States)

    Picollo, Marcello; Bartolozzi, Giovanni; Cucci, Costanza; Galeotti, Monica; Marchiafava, Veronica; Pizzo, Benedetto

    2014-01-01

    This study was completed within the framework of two research projects dealing with the conservation of contemporary artworks. The first is the Seventh Framework Project (FP7) of the European Union, Preservation of Plastic ARTefacts in Museum Collections (POPART), spanning years 2008-2012, and the second is the Italian project funded by the Tuscan Region, Preventive Conservation of Contemporary Art (Conservazione Preventiva dell'Arte Contemporanea (COPAC)), spanning 2011-2013. Both of these programs pointed out the great importance of having noninvasive and portable analytical techniques that can be used to investigate and characterize modern and contemporary artworks, especially those consisting of synthetic polymers. Indeed, despite the extensive presence of plastics in museum collections, there is still a lack of analytical tools for identifying, characterizing, and setting up adequate conservation strategies for these materials. In this work, the potentials of in situ and noninvasive Fourier transform infrared (FT-IR) spectroscopy, implemented by means of portable devices that operate in reflection mode, are investigated with a view to applying the results in large-scale surveys of plastic objects in museums. To this end, an essential prerequisite are the reliability of spectral data acquired in situ and the availability of spectral databases acquired from reference materials. A collection of polymeric samples, which are available commercially as ResinKit, was analyzed to create a reference spectral archive. All the spectra were recorded using three FT-IR configurations: transmission (trans), attenuated total reflection (ATR), and total reflection (TR). A comparative evaluation of the data acquired using the three instrumental configurations is presented, together with an evaluation of the similarity percentages and a discussion of the critical cases.

  12. Modeling and Forecasting of Depletion of Additives in Car Engine Oils Using Attenuated Total Reflectance Fast Transform Infrared Spectroscopy

    OpenAIRE

    Ronald Nguele; Hikmat Said Al-Salim; Khalid Mohammad

    2014-01-01

    On average, additives make up to 7% of a typical lubricant base. Commonly, they are blended with lube oils to enhance specific features thereby improving their qualities. Ultimately, additives participate in the performance of car engine oils. Using an analytical tool, attenuated total reflectance fast transform infrared spectroscopy, various grades of car engine oils, at different mileages, were analyzed. Sulfate oxidation and wear were found to trigger chemical processes which, in the long ...

  13. Complexation of polyacrylates by Ca2+ ions. Time-resolved studies using attenuated total reflectance Fourier transform infrared dialysis spectroscopy.

    Science.gov (United States)

    Fantinel, Fabiana; Rieger, Jens; Molnar, Ferenc; Hübler, Patrick

    2004-03-30

    The attenuated total reflectance Fourier transform infrared dialysis technique is introduced for the time-resolved investigation of the binding processes of Ca2+ to polyacrylates dissolved in water. We observed transient formation of intermediates in water with various types of coordination of the carboxylate group to Ca2+ throughout the complexation steps. Time-resolved changes in the spectra were analyzed with principal component analysis, from which the spectral species were obtained as well as their formation kinetics. We propose a model for the mechanisms of Ca2+ coordination to polyacrylates. The polymer chain length plays an important role in Ca2+ binding. PMID:15835120

  14. Beam Propagation Method Calculating Attenuated Total Reflection Spectra to Excite Hybridized Surface Plasmon Polaritons

    Directory of Open Access Journals (Sweden)

    Hongli Zhou

    2015-08-01

    Full Text Available Using the beam propagation method, an analytical expression of the reflection spectra of a Kretschmann configuration is derived in order to excite hybridized surface plasmonic polaritons (HSPPs. In this configuration, the cladding is a uniaxial dielectric with the optical axis parallel to the interface. The validity of the analytical expression is confirmed by a finite-difference time-domain algorithm and a reported experimental result, respectively. Based on this expression, the properties and the conditions for excitation of the HSPPs are discussed in detail, with regard to the strongly anisotropic cladding and the weakly anisotropic cladding.

  15. p-polarized infrared attenuated total reflection study of InN thin films grown on Si(111) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Ng, S.S.; Lee, S.C.; Ooi, P.K.; Hassan, Z.; Abu Hassan, H. [Nano-Optoelectronic Research Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Chen, W.L. [Department of Electronic Engineering, National Changhua University of Education, Taiwan 500 (China)

    2010-09-15

    We report for the first time the surface phonon polariton (SPP) and interface phonon polariton (IPP) characteristics of InN thin films grown on AlN buffer layer on Si(111) substrate by molecular beam epitaxy. The p-polarized infrared attenuated total reflection technique was used to excite the SPP and IPP modes of the sample. It was found that the SPP mode of InN and the IPP mode of InN/AlN were clearly ob- served at 609 cm{sup -1} and 877 cm{sup -1}, respectively. The origins of the observed peaks were verified by theoretical simulations based on the anisotropic model. In general, a good agreement between the experimental and theoretical results was obtained. Finally, the effect of the free carriers on the SPP mode is discussed. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Chemometric analysis of attenuated total reflectance infrared spectra of Proteus mirabilis strains with defined structures of LPS.

    Science.gov (United States)

    Zarnowiec, Paulina; Mizera, Andrzej; Chrapek, Magdalena; Urbaniak, Mariusz; Kaca, Wieslaw

    2016-07-01

    Proteus spp. strains are some of the most important pathogens associated with complicated urinary tract infections and bacteremia affecting patients with immunodeficiency and long-term urinary catheterization. For epidemiological purposes, various molecular typing methods have been developed for this pathogen. However, these methods are labor intensive and time consuming. We evaluated a new method of differentiation between strains. A collection of Proteus spp. strains was analyzed by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy in the mid-infrared region. ATR FT-IR spectroscopy used in conjunction with a diamond ATR accessory directly produced the biochemical profile of the surface chemistry of bacteria. We conclude that a combination of ATR FT-IR spectroscopy and mathematical modeling provides a fast and reliable alternative for discrimination between Proteus isolates, contributing to epidemiological research. PMID:27189426

  17. Historical perspective and modern applications of Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR).

    Science.gov (United States)

    Blum, Marc-Michael; John, Harald

    2012-01-01

    Vibrational spectroscopy has a long history as an important spectroscopic method in chemical and pharmaceutical analysis. Instrumentation for infrared (IR) spectroscopy was revolutionized by the introduction of Fourier Transform Infrared (FTIR) spectrometers. In addition, easier sampling combined with better sample-to-sample reproducibility and user-to-user spectral variation became available with attenuated total reflectance (ATR) probes and their application for in situ IR spectroscopy. These innovations allow many new applications in chemical and pharmaceutical analysis, such as the use of IR spectroscopy in Process Analytical Chemistry (PAC), the quantitation of drugs in complex matrix formulations, the analysis of protein binding and function and in combination with IR microscopy to the emergence of IR imaging technologies. The use of ATR-FTIR instruments in forensics and first response to 'white powder' incidents is also discussed. A short overview is given in this perspective article with the aim to renew and intensify interest in IR spectroscopy.

  18. Determination of antioxidant capacity and phenolic content of chocolate by attenuated total reflectance-Fourier transformed-infrared spectroscopy.

    Science.gov (United States)

    Hu, Yaxi; Pan, Zhi Jie; Liao, Wen; Li, Jiaqi; Gruget, Pierre; Kitts, David D; Lu, Xiaonan

    2016-07-01

    Antioxidant capacity and phenolic content of chocolate, containing different amounts of cacao (35-100%), were determined using attenuated total reflectance (ATR)-Fourier transformed-infrared (FT-IR) spectroscopy (4000-550cm(-1)). Antioxidant capacities were first characterized using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity) assays. Phenolic contents, including total phenol and procyanidins monomers, were quantified using the Folin-Ciocalteu assay and high performance liquid chromatography coupled with photodiode array detector (HPLC-DAD), respectively. Five partial least-squares regression (PLSR) models were constructed and cross-validated using FT-IR spectra from 18 types of chocolate and corresponding reference values determined using DPPH, ORAC, Folin-Ciocalteu, and HPLC assays. The models were validated using seven unknown samples of chocolate. PLSR models showed good prediction capability for DPPH [R(2)-P (prediction)=0.88, RMSEP (root mean squares error of prediction)=12.62μmol Trolox/g DFW], ORAC (R(2)-P=0.90, RMSEP=37.92), Folin-Ciocalteu (R(2)-P=0.88, RMSEP=5.08), and (+)-catechin (R(2)-P=0.86, RMSEP=0.10), but lacked accuracy in the prediction of (-)-epicatechin (R(2)-P=0.72, RMSEP=0.57). ATR-FT-IR spectroscopy can be used for rapid prediction of antioxidant capacity, total phenolic content, and (+)-catechin in chocolate. PMID:26920292

  19. Characterization of nasal paraffinoma following septorhinoplasty by attenuated total reflection--fourier transform infrared spectroscopy (ATR-FTIR).

    Science.gov (United States)

    Gil-Carcedo, Luis M; Martín-Gil, Jesús; Gil-Carcedo, Elisa S; Vallejo, Luis A; Martín-Gil, Francisco J

    2006-06-01

    Vaseline and paraffin have been injected into various parts of the body. Vaselinoma and paraffinoma are well-described complications, despite which nasal packing with Vaseline gauze is still common in the management of epistaxis, after rhinoplasty, endonasal surgery, to control bleeding and prevent synechiae or restenosis. Our aim is to highlight this complication, propose a safe method for its diagnosis and establish guidelines for its prevention. We report two cases of paraffinoma occurring after rhinoplasty and discuss prevention of this rare but serious complication, and suggest an alternative dressing. Attenuated total reflection (ATR) FI7R spectra have proven to be a definitive characterising tool for surgical extracts, guaranteeing detection of mineral products that histology does not offer. For these lesions we propose the name "petroleum oilomas" which we feel to be more appropriate than the more commonly used paraffinomas. Relevance of the work: a description of an innovative and safe method of diagnosis, and proposal of a procedure for postrhinoplasty packing (without mineral oils) to avoid this complication. PMID:16792177

  20. Application of multibounce attenuated total reflectance fourier transform infrared spectroscopy and chemometrics for determination of aspartame in soft drinks.

    Science.gov (United States)

    Khurana, Harpreet Kaur; Cho, Il Kyu; Shim, Jae Yong; Li, Qing X; Jun, Soojin

    2008-02-13

    Aspartame is a low-calorie sweetener commonly used in soft drinks; however, the maximum usage dose is limited by the U.S. Food and Drug Administration. Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance sampling accessory and partial least-squares regression (PLS) was used for rapid determination of aspartame in soft drinks. On the basis of spectral characterization, the highest R2 value, and lowest PRESS value, the spectral region between 1600 and 1900 cm(-1) was selected for quantitative estimation of aspartame. The potential of FTIR spectroscopy for aspartame quantification was examined and validated by the conventional HPLC method. Using the FTIR method, aspartame contents in four selected carbonated diet soft drinks were found to average from 0.43 to 0.50 mg/mL with prediction errors ranging from 2.4 to 5.7% when compared with HPLC measurements. The developed method also showed a high degree of accuracy because real samples were used for calibration, thus minimizing potential interference errors. The FTIR method developed can be suitably used for routine quality control analysis of aspartame in the beverage-manufacturing sector.

  1. Rapid Quantification of Methamphetamine: Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Chemometrics

    Science.gov (United States)

    Hughes, Juanita; Ayoko, Godwin; Collett, Simon; Golding, Gary

    2013-01-01

    In Australia and increasingly worldwide, methamphetamine is one of the most commonly seized drugs analysed by forensic chemists. The current well-established GC/MS methods used to identify and quantify methamphetamine are lengthy, expensive processes, but often rapid analysis is requested by undercover police leading to an interest in developing this new analytical technique. Ninety six illicit drug seizures containing methamphetamine (0.1%–78.6%) were analysed using Fourier Transform Infrared Spectroscopy with an Attenuated Total Reflectance attachment and Chemometrics. Two Partial Least Squares models were developed, one using the principal Infrared Spectroscopy peaks of methamphetamine and the other a Hierarchical Partial Least Squares model. Both of these models were refined to choose the variables that were most closely associated with the methamphetamine % vector. Both of the models were excellent, with the principal peaks in the Partial Least Squares model having Root Mean Square Error of Prediction 3.8, R2 0.9779 and lower limit of quantification 7% methamphetamine. The Hierarchical Partial Least Squares model had lower limit of quantification 0.3% methamphetamine, Root Mean Square Error of Prediction 5.2 and R2 0.9637. Such models offer rapid and effective methods for screening illicit drug samples to determine the percentage of methamphetamine they contain. PMID:23936058

  2. Rapid quantification of methamphetamine: using attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR and chemometrics.

    Directory of Open Access Journals (Sweden)

    Juanita Hughes

    Full Text Available In Australia and increasingly worldwide, methamphetamine is one of the most commonly seized drugs analysed by forensic chemists. The current well-established GC/MS methods used to identify and quantify methamphetamine are lengthy, expensive processes, but often rapid analysis is requested by undercover police leading to an interest in developing this new analytical technique. Ninety six illicit drug seizures containing methamphetamine (0.1%-78.6% were analysed using Fourier Transform Infrared Spectroscopy with an Attenuated Total Reflectance attachment and Chemometrics. Two Partial Least Squares models were developed, one using the principal Infrared Spectroscopy peaks of methamphetamine and the other a Hierarchical Partial Least Squares model. Both of these models were refined to choose the variables that were most closely associated with the methamphetamine % vector. Both of the models were excellent, with the principal peaks in the Partial Least Squares model having Root Mean Square Error of Prediction 3.8, R(2 0.9779 and lower limit of quantification 7% methamphetamine. The Hierarchical Partial Least Squares model had lower limit of quantification 0.3% methamphetamine, Root Mean Square Error of Prediction 5.2 and R(2 0.9637. Such models offer rapid and effective methods for screening illicit drug samples to determine the percentage of methamphetamine they contain.

  3. Investigating the structural changes of β-amyloid peptide aggregation using attenuated-total-reflection surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Chiu, K.-C.; Yu, L.-Y.; Yih, J.-N.; Chen, S.-J.

    2007-02-01

    This study utilizes a surface-enhanced Raman spectroscopy (SERS) based on the attenuated-total-reflection (ATR) method to investigate that the structural information of the biomolecular monolayer on sensing surface can be dynamically observed with a higher signal-to-noise ratio signal. The secondary structures of long oligonucleotides and their influence on the DNA hybridization on the sensing surface are investigated. The SERS spectrum provides the structural information of the oligonucleotides with the help of a silver colloidal nanoparticle monolayer by control of the size and distribution of the nanoparticles adapted as a Raman active substrate. It is found that the ring-breathing modes of adenine, thymine, guanine, and cytosine in Raman fingerprint associated with three 60mer oligonucleotides with prominent secondary structures are lower than those observed for the two oligonucleotides with no obvious secondary structures. It is also determined that increasing the DNA hybridization temperature from 35°C to 45°C reduces secondary structure effects. The ATR-SERS biosensing technique will be used to provide valuable structural information regarding the short-term reversible interactions and long-term polymerization events in the Aβ aggregates on the sensing surface.

  4. Modeling and Forecasting of Depletion of Additives in Car Engine Oils Using Attenuated Total Reflectance Fast Transform Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ronald Nguele

    2014-11-01

    Full Text Available On average, additives make up to 7% of a typical lubricant base. Commonly, they are blended with lube oils to enhance specific features thereby improving their qualities. Ultimately, additives participate in the performance of car engine oils. Using an analytical tool, attenuated total reflectance fast transform infrared spectroscopy, various grades of car engine oils, at different mileages, were analyzed. Sulfate oxidation and wear were found to trigger chemical processes which, in the long run, cause lubricant degradation while carbonyl oxidation was observed to occur only at a slow rate. Based upon data obtained from infrared spectra and using a curve fitting technique, mathematical equations predicting the theoretical rates of chemical change due to the aforementioned processes were examined. Additive depletions were found to obey exponential regression rather than polynomial. Moreover, breakpoint (breakpoint is used here to denote the initiation of deterioration of additives and critical mileage (critical mileage defines the distance at which the lubricant is chemically unusable of both samples were determined.

  5. Analysis of changes in attenuated total reflection FTIR fingerprints of Pseudomonas fluorescens from planktonic state to nascent biofilm state

    Science.gov (United States)

    Quilès, Fabienne; Humbert, François; Delille, Anne

    2010-02-01

    Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy is a useful method for monitoring biofilm in situ, non-destructively, in real time, and under fully hydrated conditions. In this work we focused on changes in Pseudomonas fluorescens ATR-FTIR fingerprint accompanying the very early stages of biofilm formation: initial bacterial adhesion and the very beginning of biofilm development in the presence of nutrients. To help interpreting variations in the ATR-FTIR fingerprint of sessile bacteria, ATR-FTIR spectra of planktonic bacteria in different growth phases were also examined, and the average surface coverage and spatial arrangement of bacteria on the ATR crystal were determined by epifluorescence microscopy. The proteins, nucleic acids and polysaccharides ATR-FTIR spectral data recorded during growth of sessile bacteria were shown to be linked to changes in the physiological state of the bacteria, possibly accompanied by extracellular polymeric substances production. This work clearly showed by spectroscopic method how bacteria change drastically their metabolism during the first hours of biofilm formation.

  6. Attenuated total reflection fourier transform infrared spectroscopy towards disclosing mechanism of bacterial adhesion on thermally stabilized titanium nano-interfaces.

    Science.gov (United States)

    Gopal, Judy; Chun, Sechul; Doble, Mukesh

    2016-08-01

    Titanium is widely used as medical implant material and as condenser material in the nuclear industry where its integrity is questioned due to its susceptibility to bacterial adhesion. A systematic investigation on the influence of thermally (50-800 °C) stabilized titanium (TS-Ti) nano oxide towards bacterial adhesion was carried out. The results showed that below 350 °C significant bacterio-phobicity was observed, while above 500 °C significant affinity towards bacterial cells was recorded. Conventional characterization tools such as HR-TEM and XRD did not provide much insight on the changes occurring on the oxide film with heat treatment, however, attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR) of the surface showed significant changes in the spectral pattern as a function of increasing heat treatment. It was observed that elevated OH, N-H and C=O groups and rutile titania on the TS-Ti oxide films led to higher affinity for bacterial adhesion. On the other hand low temperature TS-Ti nanooxide films (film grown at 50 °C was observed to be the most efficient anti-bacterial adhesion interface, while the 800 °C interface was the one showing highest affinity towards bacterial adhesion. This study confirms the successful application of ATR-FTIR technique for nano-oxide film characterization and towards understanding the variations in bacterial interaction of such nano interfaces. PMID:27412653

  7. Analysis of H2O in silicate glass using attenuated total reflectance (ATR) micro-FTIR spectroscopy

    Science.gov (United States)

    Lowenstern, Jacob B.; Pitcher, Bradley W.

    2013-01-01

    We present a calibration for attenuated total reflectance (ATR) micro-FTIR for analysis of H2O in hydrous glass. A Ge ATR accessory was used to measure evanescent wave absorption by H2O within hydrous rhyolite and other standards. Absorbance at 3450 cm−1 (representing total H2O or H2Ot) and 1630 cm−1 (molecular H2O or H2Om) showed high correlation with measured H2O in the glasses as determined by transmission FTIR spectroscopy and manometry. For rhyolite, wt%H2O=245(±9)×A3450-0.22(±0.03) and wt%H2Om=235(±11)×A1630-0.20(±0.03) where A3450 and A1630 represent the ATR absorption at the relevant infrared wavelengths. The calibration permits determination of volatiles in singly polished glass samples with spot size down to ~5 μm (for H2O-rich samples) and detection limits of ~0.1 wt% H2O. Basaltic, basaltic andesite and dacitic glasses of known H2O concentrations fall along a density-adjusted calibration, indicating that ATR is relatively insensitive to glass composition, at least for calc-alkaline glasses. The following equation allows quantification of H2O in silicate glasses that range in composition from basalt to rhyolite: wt%H2O=(ω×A3450/ρ)+b where ω = 550 ± 21, b = −0.19 ± 0.03, ρ = density, in g/cm3, and A3450 is the ATR absorbance at 3450 cm−1. The ATR micro-FTIR technique is less sensitive than transmission FTIR, but requires only a singly polished sample for quantitative results, thus minimizing time for sample preparation. Compared with specular reflectance, it is more sensitive and better suited for imaging of H2O variations in heterogeneous samples such as melt inclusions. One drawback is that the technique can damage fragile samples and we therefore recommend mounting of unknowns in epoxy prior to polishing. Our calibration should hold for any Ge ATR crystals with the same incident angle (31°). Use of a different crystal type or geometry would require measurement of several H2O-bearing standards to provide a crystal

  8. Dynamics of layer-by-layer growth of a polyelectrolyte multilayer studied in situ using attenuated total reflectance infrared spectroscopy.

    Science.gov (United States)

    Owusu-Nkwantabisah, Silas; Gammana, Madhira; Tripp, Carl P

    2014-10-01

    Attenuated total reflectance infrared spectroscopy (ATR-IR) was used to study the dynamic layer-by-layer (LBL) growth of a sodium polyacrylate (NaPA)/poly(diallydimethylammonium) chloride (PDADMAC) multilayer on TiO2 particles. Molecular weights (Mw) used were 30 and 60 kDa for NaPA and 8.5 and 150 kDa for PDADMAC. IR spectra were recorded in situ as a function of time and were used to obtain the dynamic mass adsorbed and bound fraction of the polymers during each deposition step. For 30 kDa NaPA layers, the dynamics of adsorption show an initial rapid rise in mass followed by a slow increase toward a plateau value upon LBL with 150 kDa PDADMAC. In contrast, the 60 kDa NaPA layers achieve a plateau quickly and do not show a slow increase toward a plateau. In the case of LBL with 150 kDa PDADMAC, the dynamics of the bound fraction of polymer per layer suggest that polymer diffusion and conformational rearrangement occur for the layers of 30 kDa NaPA but not for the 60 kDa NaPA layers. Furthermore, PDADMAC adsorption profiles show that there is no diffusion of the PDADMAC layers and that PDADMAC flattens onto the underlying layer. A linear growth in the mass adsorbed per layer was observed for 150 kDa PDADMAC with both molecular weights of NaPA. In the case of 8.5 kDa PDADMAC, smaller growth increments and the desorption of underlying layers were observed. This work demonstrates the use of ATR-IR in obtaining the dynamics of LBL multilayer formation. Furthermore, it provides an example in which polymer diffusion during LBL film formation does not lead to exponential growth. PMID:25203136

  9. Fourier transform infrared with attenuated total reflectance applied to the discrimination of freshwater planktonic coccoid green microalgae.

    Directory of Open Access Journals (Sweden)

    Guilherme Pavan de Moraes

    Full Text Available Despite the recent advances on fine taxonomic discrimination in microorganisms, namely using molecular biology tools, some groups remain particularly problematic. Fine taxonomy of green algae, a widely distributed group in freshwater ecosystems, remains a challenge, especially for coccoid forms. In this paper, we propose the use of the Fourier Transform Infrared (FTIR spectroscopy as part of a polyphasic approach to identify and classify coccoid green microalgae (mainly order Sphaeropleales, using triplicated axenic cultures. The attenuated total reflectance (ATR technique was tested to reproducibility of IR spectra of the biological material, a primary requirement to achieve good discrimination of microalgal strains. Spectral window selection was also tested, in conjunction with the first derivative treatment of spectra, to determine which regions of the spectrum provided better separation and clustering of strains. The non-metric multidimensional scaling (NMDS, analysis of similarities (ANOSIM and hierarchical clusters (HCA, demonstrated a correct discrimination and classification of closely related strains of chlorophycean coccoid microalgae, with respect to currently accepted classifications. FTIR-ATR was highly reproducible, and provided an excellent discrimination at the strain level. The best separation was achieved by analyzing the spectral windows of 1500-1200 cm(-1 and 900-675 cm(-1, which differs from those used in previously studies for the discrimination of broad algal groups, and excluding spectral regions related to storage compounds, which were found to give poor discrimination. Furthermore, hierarchical cluster analyses have positioned the strains tested into clades correctly, reproducing their taxonomic orders and families. This study demonstrates that FTIR-ATR has great potential to complement classical approaches for fine taxonomy of coccoid green microalgae, though a careful spectrum region selection is needed.

  10. Fourier Transform Infrared with Attenuated Total Reflectance Applied to the Discrimination of Freshwater Planktonic Coccoid Green Microalgae

    Science.gov (United States)

    de Moraes, Guilherme Pavan; Vieira, Armando Augusto Henriques

    2014-01-01

    Despite the recent advances on fine taxonomic discrimination in microorganisms, namely using molecular biology tools, some groups remain particularly problematic. Fine taxonomy of green algae, a widely distributed group in freshwater ecosystems, remains a challenge, especially for coccoid forms. In this paper, we propose the use of the Fourier Transform Infrared (FTIR) spectroscopy as part of a polyphasic approach to identify and classify coccoid green microalgae (mainly order Sphaeropleales), using triplicated axenic cultures. The attenuated total reflectance (ATR) technique was tested to reproducibility of IR spectra of the biological material, a primary requirement to achieve good discrimination of microalgal strains. Spectral window selection was also tested, in conjunction with the first derivative treatment of spectra, to determine which regions of the spectrum provided better separation and clustering of strains. The non-metric multidimensional scaling (NMDS), analysis of similarities (ANOSIM) and hierarchical clusters (HCA), demonstrated a correct discrimination and classification of closely related strains of chlorophycean coccoid microalgae, with respect to currently accepted classifications. FTIR-ATR was highly reproducible, and provided an excellent discrimination at the strain level. The best separation was achieved by analyzing the spectral windows of 1500–1200 cm−1 and 900–675 cm−1, which differs from those used in previously studies for the discrimination of broad algal groups, and excluding spectral regions related to storage compounds, which were found to give poor discrimination. Furthermore, hierarchical cluster analyses have positioned the strains tested into clades correctly, reproducing their taxonomic orders and families. This study demonstrates that FTIR-ATR has great potential to complement classical approaches for fine taxonomy of coccoid green microalgae, though a careful spectrum region selection is needed. PMID:25541701

  11. A novel, direct, reagent-free method for the detection of beeswax adulteration by single-reflection attenuated total reflectance mid-infrared spectroscopy.

    Science.gov (United States)

    Maia, Miguel; Barros, Ana I R N A; Nunes, Fernando M

    2013-03-30

    In this work, a novel, direct, reagent-free method for the detection of beeswax adulteration by paraffin, microcrystalline wax, tallow and stearic acid using single-reflection attenuated total reflectance mid-infrared spectroscopy was developed. The use of the absorbance ratios of [Formula: see text] , [Formula: see text] and [Formula: see text] allows a minimum of 5% paraffin/microcrystalline wax and tallow adulteration and 0.5% stearic acid adulteration of beeswax to be detected. The upper and lower critical limits for beeswax authenticity were established from the analysis of virgin beeswax and were validated by independent analysis of real sheet and comb beeswax samples using high-temperature gas chromatography with flame-ionization detection. In addition to its simplicity with respect to sample handling, the amount of sample and the time needed are far less than those required in previously described methods, which are based on chemical analysis and chromatographic techniques. These advantages result in time and cost savings, an increase in the number of samples that can be analyzed, and, most importantly, the detection of the main beeswax adulterants using a single method.

  12. Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy and chemometric techniques for the determination of adulteration in petrodiesel/biodiesel blends

    OpenAIRE

    Armando Guerrero Peña; Francisco Anguebes Franseschi; Mepivoseth Castelán Estrada; Victorino Morales Ramos; Reyes García Zarracino; José C. Zavala Loría; Atl V. Córdova Quiroz

    2014-01-01

    We propose an analytical method based on fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy to detect the adulteration of petrodiesel and petrodiesel/palm biodiesel blends with African crude palm oil. The infrared spectral fingerprints from the sample analysis were used to perform principal components analysis (PCA) and to construct a prediction model using partial least squares (PLS) regression. The PCA results separated the samples into three groups, allowing id...

  13. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy and Artificial Neural Networks Applied to Differentiate Escherichia coli papG+/papG- Strains

    OpenAIRE

    Łukasz Lechowicz; Wioletta Adamus-Białek; Wiesław Kaca

    2013-01-01

    Fimbriae are an important pathogenic factor of Escherichia coli during development of urinary tract infections. Here, we describe a new method for identification of Escherichia coli papG+ from papG- strains using the attenuated total reflectance Fourier transform infrared Spectroscopy (ATR FT-IR). We applied artificial neural networks to the analysis of the ATR FT-IR results. These methods allowed to discriminate E. coli papG+ from papG- strains with accuracy of 99%.

  14. Orientation and lipid-peptide interactions of gramicidin A in lipid membranes: Polarized attenuated total reflection infrared spectroscopy and spin-label electron spin resonance

    OpenAIRE

    Kota, Z.; Pali, T.; Marsh, D.

    2004-01-01

    Gramicidin A was incorporated at a peptide/lipid ratio of 1:10 mol/mol in aligned bilayers of dimyristoyl phosphatidylcholine (DMPC), phosphatidylserine (DMPS), phosphatidylglycerol (DMPG), and phosphatidylethanolamine (DMPE), from trifluoroethanol. Orientations of the peptide and lipid chains were determined by polarized attenuated total reflection infrared spectroscopy. Lipid-peptide interactions with gramicidin A in DMPC bilayers were studied with different spin-labeled lipid species by us...

  15. Study of interfacial reactions and phase stabilization of mixed Sc, Dy, Hf high-k oxides by attenuated total reflectance infrared spectroscopy

    OpenAIRE

    Hardy, An; Adelmann, C; Van Elshocht, S.; Van den Rul, Heidi; Van Bael, Marlies; de Gendt, S.; D'Olieslaeger, Marc; Heyns, M.; Kittl, J. A.; Mullens, Jules

    2009-01-01

    Grazing angle attenuated total reflectance Fourier transform infrared spectroscopy is applied to study ultrathin film Hf4+, Sc3+ and Dy3+ oxides, due to its high surface sensitivity. The (multi) metal oxides studied, are of interest as high-k dielectrics. Important properties affecting the permittivity, such as the amorphous or crystalline phase and interfacial reactions, are characterized. Dy2O3 is prone to silicate formation on SiO2/Si substrates, which is expressed in DyScO3 as well, but s...

  16. Classification of pumpkin seed oils according to their species and genetic variety by attenuated total reflection Fourier-transform infrared spectroscopy.

    Science.gov (United States)

    Saucedo-Hernández, Yanelis; Lerma-García, María Jesús; Herrero-Martínez, José Manuel; Ramis-Ramos, Guillermo; Jorge-Rodríguez, Elisa; Simí-Alfonso, Ernesto F

    2011-04-27

    Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), followed by multivariate treatment of the spectral data, was used to classify seed oils of the genus Cucurbita (pumpkins) according to their species as C. maxima, C. pepo, and C. moschata. Also, C. moschata seed oils were classified according to their genetic variety as RG, Inivit C-88, and Inivit C-2000. Up to 23 wavelength regions were selected on the spectra, each region corresponding to a peak or shoulder. The normalized absorbance peak areas within these regions were used as predictors. Using linear discriminant analysis (LDA), an excellent resolution among all categories concerning both Cucurbita species and C. moschata varieties was achieved. The proposed method was straightforward and quick and can be easily implemented. Quality control of pumpkin seed oils is important because Cucurbita species and genetic variety are both related to the pharmaceutical properties of the oils.

  17. Detection of counterfeit Scotch whisky samples using mid-infrared spectrometry with an attenuated total reflectance probe incorporating polycrystalline silver halide fibres.

    Science.gov (United States)

    McIntyre, Allyson C; Bilyk, Madeleine L; Nordon, Alison; Colquhoun, Gary; Littlejohn, David

    2011-04-01

    Two methods of analysis were developed to permit detection of counterfeit Scotch whisky samples using a novel attenuated total reflectance (ATR) diamond-tipped immersion probe for mid-infrared (MIR) spectrometry. The first method allowed determination of the ethanol concentration (35-45% (v/v)) in situ without dilution of the samples; the results obtained compared well with the supplied concentrations (average relative error of 1.2% and 0.8% for univariate and multivariate partial least squares (PLS) calibration, respectively). The second method involved analysis of dried residues of the whisky samples and caramel solutions on the diamond ATR crystal; principal component analysis (PCA) of the spectra was used to classify the samples and investigate the colorant added. Seventeen test whisky samples were successfully categorised as either authentic or counterfeit in a blind study when both MIR methods were used.

  18. Optical and electrochemical evaluation of colloidal Au nanoparticle-ITO hybrid optically transparent electrodes and their application to attenuated total reflectance spectroelectrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, John N.; Aguilar, Zoraida; Kaval, Necati; Andria, Sara E.; Shtoyko, Tanya; Seliskar, Carl J.; Heineman, William R

    2003-12-15

    Colloidal Au nanoparticle monolayers covalently deposited on conductive layers of indium tin oxide (ITO) were fabricated and evaluated as optically transparent electrodes (OTEs) for spectroelectrochemical applications. Specifically, the electrodes were characterized using UV-Vis spectroscopy and cyclic voltammetry; comparisons are made with other types of hybrid ITO optically transparent electrodes. The optical modulation of surface-bound colloidal Au in response to potential cycling over a wide potential window (0.6 to -1.0 V) was acquired in an attenuated total reflectance (ATR) spectroelectrochemical cell. Finally, uptake of a model analyte, tris-(2,2'-bipyridyl)ruthenium(II) chloride, into a Nafion charge selective film spin coated onto the colloidal Au-ITO hybrid electrode was examined using ATR absorbance spectroelectrochemistry. Dependence of uptake on film thickness is addressed, and non-optimized detection limits of 10 nM are reported.

  19. CO 2 Capture Capacity and Swelling Measurements of Liquid-like Nanoparticle Organic Hybrid Materials via Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

    KAUST Repository

    Park, Youngjune

    2012-01-12

    Novel nanoparticle organic hybrid materials (NOHMs), which are comprised of organic oligomers or polymers tethered to an inorganic nanosized cores of various sizes, have been synthesized, and their solvating property for CO 2 was investigated using attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy. Simultaneous measurements of CO 2 capture capacity and swelling behaviors of polyetheramine (Jeffamine M-2070) and its corresponding NOHMs (NOHM-I-PE2070) were reported at temperatures of (298, 308, 323 and 353) K and CO 2 pressure conditions ranging from (0 to 5.5) MPa. The polymeric canopy, or polymer bound to the nanoparticle surface, showed significantly less swelling behavior with enhanced or comparable CO 2 capture capacity compared to pure unbound polyetheramine. © 2011 American Chemical Society.

  20. Origin identification of dried distillers grains with solubles using attenuated total reflection Fourier transform mid-infrared spectroscopy after in situ oil extraction.

    Science.gov (United States)

    Vermeulen, Ph; Fernández Pierna, J A; Abbas, O; Dardenne, P; Baeten, V

    2015-12-15

    The ban on using processed animal proteins in feedstuffs led the feed sector to look for other sources of protein. Dried distillers grains with solubles (DDGS) could be considered as an important source in this regard. They are imported into Europe mainly for livestock feed. Identifying their origin is essential when labelling is missing and for feed safety, particularly in a crisis situation resulting from contamination. This study investigated applying attenuated total reflection Fourier transform mid-infrared spectroscopy (ATR-FT-MIR) to the oil fraction extracted from samples in situ in order to identify the origin of DDGS. The use of spectroscopic and chemometric tools enabled the botanical and geographical origins of DDGS, as well as the industrial process used to produce them, to be identified. The models developed during the study provided a classification higher than 95% using an external validation set. PMID:26190596

  1. Fourier transform infrared-attenuated total reflectance (FTIR-ATR spectroscopy and chemometric techniques for the determination of adulteration in petrodiesel/biodiesel blends

    Directory of Open Access Journals (Sweden)

    Armando Guerrero Peña

    2014-06-01

    Full Text Available We propose an analytical method based on fourier transform infrared-attenuated total reflectance (FTIR-ATR spectroscopy to detect the adulteration of petrodiesel and petrodiesel/palm biodiesel blends with African crude palm oil. The infrared spectral fingerprints from the sample analysis were used to perform principal components analysis (PCA and to construct a prediction model using partial least squares (PLS regression. The PCA results separated the samples into three groups, allowing identification of those subjected to adulteration with palm oil. The obtained model shows a good predictive capacity for determining the concentration of palm oil in petrodiesel/biodiesel blends. Advantages of the proposed method include cost-effectiveness and speed; it is also environmentally friendly.

  2. Fluorescence, CD, attenuated total reflectance (ATR) FTIR, and sup 13 C NMR characterization of the structure and dynamics of synthetic melittin and melittin analogues in lipid environments

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, A.J.; Prendergast, F.G. (Mayo Foundation, Rochester, MN (United States)); Kemple, M.D. (Indiana Univ.-Purdue Univ., Indianapolis (United States)); Brauner, J.W.; Mendelsohn, R. (Rutgers, The State Univ. of New Jersey, Newark (United States))

    1992-02-11

    The structure and dynamics of synthetic melittin (MLT) and MLT analogues bound to monomyristoylphosphatidylcholine micelles, dimyristoylphosphatidylcholine vesicles, and diacylphosphatidylcholine films have been investigated by fluorescence, CD, attenuated total reflectance (ATR) FTIR, and {sup 13}C NMR spectroscopy. All of these methods provide information about peptide secondary structure and/or about the environment of the single tryptophan side chain in these lipid environments. ATR-FTIR data provide additional information about the orientation of helical peptide segments with respect to the bilayer plane. Steady-state fluorescence anisotropy, fluorescence lifetime, and {sup 13}C NMR relaxation data are used in concert to provide quantitative information about the dynamics of a single {sup 13}C{alpha}-labeled glycine incorporated into each of the MLT peptides at position 12. The cumulative structural and dynamic data are consistent with a model wherein the N-terminal {alpha}-helical segment of these peptides is oriented perpendicular to the bilayer plane. Correlation times for the lysolipid-peptide complexes provide evidence for binding of a single peptide monomer per micelle. A model for the membranolytic action of MLT and MLT-like peptides is proposed.

  3. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy on Intact Dried Leaves of Sage (Salvia officinalis L.): Accelerated Chemotaxonomic Discrimination and Analysis of Essential Oil Composition.

    Science.gov (United States)

    Gudi, Gennadi; Krähmer, Andrea; Krüger, Hans; Schulz, Hartwig

    2015-10-01

    Sage (Salvia officinalis L.) is cultivated worldwide for its aromatic leaves, which are used as herbal spice, and for phytopharmaceutical applications. Fast analytical strategies for essential oil analysis, performed directly on plant material, would reduce the delay between sampling and analytical results. This would enhance product quality by improving technical control of cultivation. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) method described here provides a reliable calibration model for quantification of essential oil components [EOCs; R(2) = 0.96; root-mean-square error of cross-validation (RMSECV) = 0.249 mL 100 g(-1) of dry matter (DM); and range = 1.115-5.280 mL 100 g(-1) of DM] and main constituents [e.g., α-thujone/β-thujone; R(2) = 0.97/0.86; RMSECV = 0.0581/0.0856 mL 100 g(-1) of DM; and range = 0.010-1.252/0.005-0.893 mL 100 g(-1) of DM] directly on dried intact leaves of sage. Except for drying, no further sample preparation is required for ATR-FTIR, and the measurement time of less than 5 min per sample contrasts with the most common alternative of hydrodistillation followed by gas chromatography analysis, which can take several hours per sample.

  4. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-03-30

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (Penamel erosion.

  5. Preparation and transmission characteristics of a mid-infrared attenuated total reflection hollow waveguide based on a stainless steel capillary tube.

    Science.gov (United States)

    Wang, Xu; Guo, Hong; Wang, Lin; Yue, Fangyu; Jing, Chengbin; Chu, Junhao

    2016-08-10

    Stainless steel (SUS) capillary tubes were examined as a category of structural tube for establishing a metallic attenuated total reflection (ATR) GeO2 hollow waveguide. GeO2 films were grown on the inner wall of SUS tubes by different liquid phase deposition (LPD) cycles. Fourier transform infrared (FTIR) spectra, scanning electronic microscope (SEM) image, and transmission loss for a CO2 laser were measured to investigate the effects of the LPD cycles on the transmission behavior of the hollow waveguide samples. The film thickness and surface roughness increase with every LPD cycle. The two LPD cycle sample has a film thickness equivalent to the CO2 laser wavelength, while the surface roughness is acceptable. This sample has the lowest transmission loss (0.27  dB/m) among these samples. The bending loss, output beam profile, and full divergence angle (FDA) were further studied. Higher-order modes are excited by bending the sample, inducing additional loss, decentralized beam profile, and larger FDA. PMID:27534486

  6. Development and validation of an environmentally friendly attenuated total reflectance in the mid-infrared region method for the determination of ethanol content in used engine lubrication oil.

    Science.gov (United States)

    Hatanaka, Rafael Rodrigues; Sequinel, Rodrigo; Gualtieri, Carlos Eduardo; Tercini, Antônio Carlos Bergamaschi; Flumignan, Danilo Luiz; de Oliveira, José Eduardo

    2013-05-15

    Lubricating oils are crucial in the operation of automotive engines because they both reduce friction between moving parts and protect against corrosion. However, the performance of lubricant oil may be affected by contaminants, such as gasoline, diesel, ethanol, water and ethylene glycol. Although there are many standard methods and studies related to the quantification of contaminants in lubricant oil, such as gasoline and diesel oil, to the best of our knowledge, no methods have been reported for the quantification of ethanol in used Otto cycle engine lubrication oils. Therefore, this work aimed at the development and validation of a routine method based on partial least-squares multivariate analysis combined with attenuated total reflectance in the mid-infrared region to quantify ethanol content in used lubrication oil. The method was validated based on its figures of merit (using the net analyte signal) as follows: limit of detection (0.049%), limit of quantification (0.16%), accuracy (root mean square error of prediction=0.089% w/w), repeatability (0.05% w/w), fit (R(2)=0.9997), mean selectivity (0.047), sensitivity (0.011), inverse analytical sensitivity (0.016% w/w(-1)) and signal-to-noise ratio (max: 812.4 and min: 200.9). The results show that the proposed method can be routinely implemented for the quality control of lubricant oils. PMID:23618159

  7. Using attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) to study the molecular conformation of parchment artifacts in different macroscopic states.

    Science.gov (United States)

    Gonzalez, Lee; Wade, Matthew; Bell, Nancy; Thomas, Kate; Wess, Tim

    2013-02-01

    Maintaining appropriate temperatures and relative humidity is considered essential to extending the useful life of parchment artifacts. Although the relationship between environmental factors and changes to the physical state of artifacts is reasonably understood, an improved understanding of the relationship between the molecular conformation and changes to the macroscopic condition of parchment is needed to optimize environmental conditions. Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FT-IR) analysis, the conformation of the molecular structure in selected parchment samples with specific macroscopic conditions, typically discoloration and planar deformations (e.g., cockling and tearing), have been made. The results of this investigation showed that the Fourier transform infrared signal differs for parchment samples exhibiting different macroscopic conditions. In areas exhibiting planar deformation, a change in the Fourier Transform Infrared signal was observed that indicates unfolding of the molecular conformation. In comparison, the discolored samples showed a change in molecular conformation that indicates a chemical change within the collagen molecular structure. This paper discusses the possible causal associations and implications of these findings for the conservation and preservation of parchment artifacts.

  8. Structure and orientation of two voltage-dependent anion-selective channel isoforms. An attenuated total reflection fourier-transform infrared spectroscopy study.

    Science.gov (United States)

    Abrecht, H; Goormaghtigh, E; Ruysschaert, J M; Homble, F

    2000-12-29

    Two VDAC (voltage-dependent anion-selective channel) isoforms were purified from seed cotyledons of Phaseolus vulgaris by chromatofocusing chromatography. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy was used to study the structural properties of the two isoforms reconstituted in a mixture of asolectin and 5% stigmasterol. The IR spectra of the two VDAC isoforms were highly similar indicating 50 to 53% anti-parallel beta-sheet. The orientation of the beta-strands relative to the barrel axis was calculated from the experimentally obtained dichroic ratios of the amide I beta-sheet component and the amide II band. Comparing the IR spectra of the reconstituted VDAC isoforms with the IR spectra of the bacterial porin OmpF, for which a high resolution structure is available, provided evidence for a general structural organization of the VDAC isoforms similar to that of bacterial porins. Hydrogen-deuterium exchange measurements indicated that the exchange of the amide protons occurs to a higher extent in the two VDAC isoforms than in the OmpF porin.

  9. A Catalytic Path for Electrolyte Reduction in Lithium-Ion Cells Revealed by in Situ Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy

    KAUST Repository

    Shi, Feifei

    2015-03-11

    © 2015 American Chemical Society. Although controlling the interfacial chemistry of electrodes in Li-ion batteries (LIBs) is crucial for maintaining the reversibility, electrolyte decomposition has not been fully understood. In this study, electrolyte decomposition on model electrode surfaces (Au and Sn) was investigated by in situ attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Simultaneously obtained ATR-FTIR spectra and cyclic voltammetry measurements show that lithium ethylene dicarbonate and lithium propionate form on the Au electrode at 0.6 V, whereas diethyl 2,5-dioxahexane dicarboxylate and lithium propionate form on the Sn electrode surface at 1.25 V. A noncatalytic reduction path on the Au surface and a catalytic reduction path on the Sn surface are introduced to explain the surface dependence of the overpotential and product selectivity. This represents a new concept for explaining electrolyte reactions on the anode of LIBs. The present investigation shows that catalysis plays a dominant role in the electrolyte decomposition process and has important implications in electrode surface modification and electrolyte recipe selection, which are critical factors for enhancing the efficiency, durability, and reliability of LIBs.

  10. Evaluation of low trans fat edible oils by attenuated total reflection-Fourier transform infrared spectroscopy and gas chromatography: a comparison of analytical approaches.

    Science.gov (United States)

    Tyburczy, Cynthia; Mossoba, Magdi M; Fardin-Kia, Ali Reza; Rader, Jeanne I

    2012-08-01

    Current interest by the food industry in exploring reformulation options that lower the content of trans fat in edible fats and oils requires methods to accurately measure low levels of trans fat. In the present study, the quantitation of trans fat in 25 edible fat and oil samples was evaluated using two current analytical approaches, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and gas chromatography with flame ionization detection (GC-FID) according to Official Methods of the American Oil Chemists' Society. Significant differences between the ATR-FTIR and reference GC-FID quantitations were found for samples with a trans fat content fat. These discrepancies could be explained, in part, by the presence of certain oil constituents (e.g., vitamins, carotenoids, high levels of saturated fat) that produced absorbance bands at or near 966 cm(-1) in the ATR-FTIR spectra, a region that was previously identified as being characteristic of isolated trans double bonds. Results demonstrate that the natural content of such oil constituents could result in significant overestimations of trans fat when ATR-FTIR is used to analyze edible fats and oils with a trans fat content fat.

  11. Mechanism of formation of humus coatings on mineral surfaces 2. Attenuated total reflectance spectra of hydrophobic and hydrophilic fractions of organic acids from compost leachate on alumina

    Science.gov (United States)

    Wershaw, R. L.; Llaguno, E.C.; Leenheer, J.A.; Sperline, R.P.; Song, Y.

    1996-01-01

    Hydrophobic and hydrophilic fractions were isolated from a compost leachate. The adsorption isotherms of both fractions on alumina were measured by attenuated total reflectance infrared spectroscopy. The shapes of the adsorption isotherms of the two fractions were different. The isotherms for the hydrophilic fraction showed little change in surface excess with increasing solution concentration above 4 mg L-1. The isotherms for the hydrophobic fraction, on the other hand, displayed a marked increase in surface excess with increasing solution concentration. This increase is evidence for the formation of aggregates (admicelles or hemimicelles) on the alumina surface. Linear dichroism calculations indicated that more of the carboxylate groups in the adsorbed hydrophobic molecules than in the absorbed hydrophilic fraction were free to rotate. The hindered rotation of the carboxylate groups in the adsorbed hydrophilic-fraction molecules probably indicates that these groups are bound to surface aluminum ions by a bidentate mechanism in which the two oxygen atoms of a single carboxylate group bind to separate aluminum ions.

  12. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy

    International Nuclear Information System (INIS)

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated

  13. Determination of water uptake of polymeric ion-selective membranes with the coulometric Karl Fischer and FT-IR-attenuated total reflection techniques.

    Science.gov (United States)

    He, Ning; Lindfors, Tom

    2013-01-15

    The water uptake of plasticized poly(vinyl chloride) (PVC) and silicone rubber (SR) based calcium-selective membranes which are commonly used in solid-contact and coated-wire ion-selective electrodes (SC-ISEs and CWEs) was quantified with the oven based coulometric Karl Fischer (KF) technique. Two different membrane types were studied: (1) the plasticized PVC or SR (RTV 3140) membrane matrix without other added membrane components and (2) the full Ca(2+)-selective membrane formulation consisting of the membrane matrixes, potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate and calcium ionophore IV (ETH 5234) or calcium ionophore I (ETH 1001). The membranes were contacted for 24 h either asymmetrically from one side or symmetrically from both sides with deionized water (DIW) or 0.1 M solutions of CaCl(2), KCl, or NaCl. It was found that the water uptake was higher for symmetrically contacted membranes. The highest water uptake (0.15-0.17 wt %) was obtained for the plasticized PVC based Ca(2+)-selective membranes in DIW, whereas the water uptake was lower in 0.1 M electrolyte solutions. Symmetrically contacted Ca(2+)-selective SR membranes had much lower water uptake in 0.1 M CaCl(2) (0.03 wt %) than their plasticized PVC counterparts (0.1 wt %). However, the (noncontacted) SR membranes contained initially much more water (0.09-0.15 wt %) than the PVC membranes (0.04-0.07 wt %). Furthermore, in good accordance with the KF measurements, it was verified with FT-IR-attenuated total reflection (ATR) spectroscopy that the water content at the substrate/membrane interface and consequently in the whole membrane was influenced by the electrolyte solution. PMID:23249325

  14. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-01-01

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion. PMID:27025266

  15. The problem of 2,4,6-trichloroanisole in cork planks studied by attenuated total reflection infrared spectroscopy: proof of concept.

    Science.gov (United States)

    Garcia, Ana R; Lopes, Luís F; Brito de Barros, Ricardo; Ilharco, Laura M

    2015-01-14

    Attenuated total reflection infrared spectroscopy (ATR-IR) proved to be a promising detection technique for 2,4,6-trichloroanisole (TCA), which confers organoleptic defects to bottled alcoholic beverages, allowing the proposal of a criterion for cork plank acceptance when meant for stopper production. By analysis of a significant number of samples, it was proved that the presence of TCA, even in very low concentrations, imparts subtle changes to the cork spectra, namely, the growth of two new bands at ∼1417 (νC═C of TCA ring) and 1314 cm–1 (a shifted νCC of TCA) and an increase in the relative intensities of the bands at ∼1039 cm–1 (δCO of polysaccharides) and ∼813 cm–1 (τCH of suberin), the latter by overlapping with intense bands of TCA. These relative intensities were evaluated in comparison to a fingerprint of suberin (νasC–O–C), at 1161 cm–1. On the basis of those spectral variables, a multivariate statistics linear analysis (LDA) was performed to obtain a discriminant function that allows classifying the samples according to whether they contain or not TCA. The methodology proposed consists of a demanding acceptance criterion for cork planks destined for stopper production (with the guarantee of nonexistence of TCA) that results from combining the quantitative results with the absence of the two TCA correlated bands. ATR infrared spectroscopy is a nondestructive and easy to apply technique, both on cork planks and on stoppers, and has proven more restrictive than other techniques used in the cork industry that analyze the cleaning solutions. At the level of proof of concept, the method here proposed is appealing for high-value stopper applications.

  16. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion:attenuated total reflection Fourier transform infrared spectroscopy

    Institute of Scientific and Technical Information of China (English)

    In-Hye Kim; Jun Sik Son; Bong Ki Min; Young Kyoung Kim; Kyo-Han Kim; Tae-Yub Kwon

    2016-01-01

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers’ microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (Po0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATRFTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion.

  17. Chemical Functionalization of Germanium with Dextran Brushes for Immobilization of Proteins Revealed by Attenuated Total Reflection Fourier Transform Infrared Difference Spectroscopy.

    Science.gov (United States)

    Schartner, Jonas; Hoeck, Nina; Güldenhaupt, Jörn; Mavarani, Laven; Nabers, Andreas; Gerwert, Klaus; Kötting, Carsten

    2015-07-21

    Protein immobilization studied by attenuated total reflection Fourier transform infrared (ATR-FT-IR) difference spectroscopy is an emerging field enabling the study of proteins at atomic detail. Gold or glass surfaces are frequently used for protein immobilization. Here, we present an alternative method for protein immobilization on germanium. Because of its high refractive index and broad spectral window germanium is the best material for ATR-FT-IR spectroscopy of thin layers. So far, this technique was mainly used for protein monolayers, which lead to a limited signal-to-noise ratio. Further, undesired protein-protein interactions can occur in a dense layer. Here, the germanium surface was functionalized with thiols and stepwise a dextran brush was generated. Each step was monitored by ATR-FT-IR spectroscopy. We compared a 70 kDa dextran with a 500 kDa dextran regarding the binding properties. All surfaces were characterized by atomic force microscopy, revealing thicknesses between 40 and 110 nm. To analyze the capability of our system we utilized N-Ras on mono-NTA (nitrilotriacetic acid) functionalized dextran, and the amount of immobilized Ras corresponded to several monolayers. The protein stability and loading capacity was further improved by means of tris-NTA for immobilization. Small-molecule-induced changes were revealed with an over 3 times higher signal-to-noise ratio compared to monolayers. This improvement may allow the observation of very small and so far hidden changes in proteins upon stimulus. Furthermore, we immobilized green fluorescent protein (GFP) and mCherry simultaneously enabling an analysis of the surface by fluorescence microscopy. The absence of a Förster resonance energy transfer (FRET) signal demonstrated a large protein-protein distance, indicating an even distribution of the protein within the dextran.

  18. Optimized data analysis algorithm for on-site chemical identification using a hand-held attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer.

    Science.gov (United States)

    Ron, Izhar; Zaltsman, Amalia; Kendler, Shai

    2013-12-01

    On-site identification of organic compounds in the presence of interfering materials using a field-portable attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer is presented. Identification is based on an algorithm that compares the analyte's infrared absorption spectrum with the reference spectra. The comparison is performed at several predetermined frequencies, and a similarity value (distance) between the measured and the reference spectra is calculated either at each frequency individually, or, alternatively, the average distance for all frequencies is calculated. The examined frequencies are selected to give the best contrast between the target materials of interest. In this study, the algorithm was optimized to identify three common chemical warfare agents (CWAs): O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioic acid (VX), sarin (GB), and sulfur mustard (bis(2-chloroethyl) sulfide) (HD), in the presence of field-related interfering materials (fuels, water, and dust). Receiver operating characteristics analysis was performed in order to determine the probabilities for detection (PD) and for false alerts (PF). Challenging the algorithm with a set of data that contains mixtures of CWAs and interfering materials resulted in PD of 90% and PF of 0%, 0%, and 1% for VX, GB, and HD, respectively, using the average distance approach, which was found to be much more effective than analyzing each frequency individually. This finding was validated for all possible combinations of 2-7 peaks per material. It is suggested that this algorithm provides a reliable mean for the identification of a predetermined set of target analytes and interfering materials.

  19. Attenuated Total Reflection-Fourier Transform Infrared Spectroscopic Study of Dried Shark Fin Products%鱼翅干制品品质的ATR-FTIR鉴别研究

    Institute of Scientific and Technical Information of China (English)

    韩婉清; 罗海英; 冼燕萍; 罗东辉; 穆同娜; 郭新东

    2015-01-01

    Sixty-four pieces of shark fin dried products (including real,fake and artificial shark fin products)and real products coated with gelatin were rapidly and nondestructively analyzed by attenuated total reflection-Fourier transform infrared spectros-copy (ATR-FTIR).The characteristic of IR spectrograms among the above four kinds of samples were systematically studied and comparied,the results showed that the spectrograms of the same kind of samples were repeatable,and different kinds of shark fin products presented significant differences in the spectrograms,which mainly manifested as the specific absorption peaks of amido bonds in protein (1 650,1 544 cm-1 )and skeletal vibration in polysaccharide (1 050 cm-1 ).The spectrograms of real shark fins were characterized by the strong absorption peaks of protein characteristic amide Ⅰ and Ⅱ absorbent (1 650,1 544 cm-1 )and relatively weak C—O—C vibration absorbent (1 050 cm-1 )owing to the high content of protein and relatively low level of polysaccharide.For fake shark fin products that were molded form by mixing together with the offcut of shark,collagen and other substances,the introduction of non-protein materials leaded to the weaker amido bonds absorbent than real products along with a 30 cm-1 blue shift of amide Ⅰabsorbent.Opposite to the real sample,the relatively strong absorption peak of poly-saccharide (~1 047 cm-1 )and barely existed amide absorbent were the key features of the spectrogram of artificial samples, which was synthersized by polysaccharide like sodium alginate.Real samples coated with gelatin,the peak strength of protein and polysaccharide were decreased simultaneously when the data collection was taken at the surface of sample,while the spectro-gram presented no significant difference to real samples when the data was collected in the section.The results above indicated that by analyzing the characteristic of IR spectrograms and the value range of Apro/Apol collected by ATR

  20. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) Mapping Coupled with Multivariate Curve Resolution (MCR) for Studying the Miscibility of Chlorobutyl Rubber/Polyamide-12 Blends.

    Science.gov (United States)

    Tang, Yongjiao; Jing, Nan; Zhang, Pudun

    2015-11-01

    A series of chlorobutyl rubber/polyamide-12 (CIIR/PA-12) blends compatibilized by different amounts of maleic anhydride (MAH) grafted polypropylene (PP-g-MAH) were investigated by attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) mapping. Multivariate curve resolution (MCR) was used to process the FT-IR images. Both the spectra of pure components in the blends and their concentration distributions in a micro-region were acquired. Our results demonstrated that the blend with 15 parts per hundred rubber PP-g-MAH showed the best miscibility. An amide interphase and an imide interphase were inferred by analyzing the spectra of MCR component 3 of the blends with and without PP-g-MAH, respectively. Correspondingly, two different compatibilizing mechanisms were proposed for these blends. PMID:26647055

  1. Label-Free Determination of Protein Binding in Aqueous Solution using Overlayer Enhanced Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (OE-ATR-FTIR)

    Science.gov (United States)

    Ruthenburg, Travis; Aweda, Tolulope; Park, Simon; Meares, Claude; Land, Donald

    2009-03-01

    Protein binding/affinity studies are often performed using Surface Plasmon Resonance techniques that don't produce much spectral information. Measurement of protein binding affinity using FTIR is traditionally performed using high protein concentration or deuterated solvent. By immobilizing a protein near the surface of a gold-coated germanium internal reflection element interactions can be measured between an immobilized protein and free proteins or small molecules in aqueous solution. By monitoring the on and off rates of these interactions, the dissociation constant for the system can be determined. The dissociation constant for the molecule Yttrium-DOTA binding to the antibody 2D12.5 system was determined to be 100nM. Results will also be presented from our measurements of Bovine Serum Albumin (BSA) binding to anti-BSA.

  2. A multivariate approach using attenuated total reflectance mid-infrared spectroscopy to measure the surface mannoproteins and β-glucans of yeast cell walls during wine fermentations.

    Science.gov (United States)

    Moore, John P; Zhang, Song-Lei; Nieuwoudt, Hélène; Divol, Benoit; Trygg, Johan; Bauer, Florian F

    2015-11-18

    Yeast cells possess a cell wall comprising primarily glycoproteins, mannans, and glucan polymers. Several yeast phenotypes relevant for fermentation, wine processing, and wine quality are correlated with cell wall properties. To investigate the effect of wine fermentation on cell wall composition, a study was performed using mid-infrared (MIR) spectroscopy coupled with multivariate methods (i.e., PCA and OPLS-DA). A total of 40 yeast strains were evaluated, including Saccharomyces strains (laboratory and industrial) and non-Saccharomyces species. Cells were fermented in both synthetic MS300 and Chardonnay grape must to stationery phase, processed, and scanned in the MIR spectrum. PCA of the fingerprint spectral region showed distinct separation of Saccharomyces strains from non-Saccharomyces species; furthermore, industrial wine yeast strains separated from laboratory strains. PCA loading plots and the use of OPLS-DA to the data sets suggested that industrial strains were enriched with cell wall proteins (e.g., mannoproteins), whereas laboratory strains were composed mainly of mannan and glucan polymers.

  3. A study of surface film formation on LiNi0.8Co0.15Al0.05O2 cathodes u sing attenuated total reflection infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Song, S.-W.; Zhuang, G.V.; Ross Jr., P.N.

    2004-01-19

    The surface films formed on commercial LiNi0.8Co0.15Al0.05O2 cathodes (ATD Gen2) charged from 3.75V to 4.2V vs. Li/Li+ in EC:DEC - 1M LiPF6 were analyzed using ex-situ Fourier transform infrared spectroscopy (FTIR) with the attenuated total reflection (ATR) technique. A surface layer of Li2CO3 is present on the virgin cathode, probably from reaction of the active material with air during the cathode preparation procedure. The Li2CO3 layer disappeared even after soaking in the electrolyte, indicating that the layer dissolved into the electrolyte possibly even before potential cycling of the electrode. IR features only from the binder (PVdF) and a trace of polyamide from the Al current collector were observed on the surfaces of cathodes charged to below 4.2 V, i.e., no surface species from electrolyte oxidation. Some new IR features were, however, found on the cathode charged to 4.2 V and higher. An electrolyte oxidation product was observed that appeared to contain dicarbonyl anhydride and (poly)ester functionalities. The reaction appears to be an indirect electrochemical oxidation with overcharging (removal of > 0.6 Li ions) destabilizing oxygen in the oxide lattice resulting in oxygen transfer to the solvent molecules.

  4. Characterization of silver halide fiber optics and hollow silica waveguides for use in the construction of a mid-infrared attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy probe.

    Science.gov (United States)

    Damin, Craig A; Sommer, André J

    2013-11-01

    Advances in fiber optic materials have allowed for the construction of fibers and waveguides capable of transmitting infrared radiation. An investigation of the transmission characteristics associated with two commonly used types of infrared-transmitting fibers/waveguides for prospective use in a fiber/waveguide-coupled attenuated total internal reflection (ATR) probe was performed. Characterization of silver halide polycrystalline fiber optics and hollow silica waveguides was done on the basis of the transmission of infrared light using a conventional fiber optic coupling accessory and an infrared microscope. Using the fiber optic coupling accessory, the average percent transmission for three silver halide fibers was 18.1 ± 6.1% relative to a benchtop reflection accessory. The average transmission for two hollow waveguides (HWGs) using the coupling accessory was 8.0 ± 0.3%. (Uncertainties in the relative percent transmission represent the standard deviations.) Reduced transmission observed for the HWGs was attributed to the high numerical aperture of the coupling accessory. Characterization of the fibers/waveguides using a zinc selenide lens objective on an infrared microscope indicated 24.1 ± 7.2% of the initial light input into the silver halide fibers was transmitted. Percent transmission obtained for the HWGs was 98.7 ± 0.1%. Increased transmission using the HWGs resulted from the absence or minimization of insertion and scattering losses due to the hollow air core and a better-matched numerical aperture. The effect of bending on the transmission characteristics of the fibers/waveguides was also investigated. Significant deviations in the transmission of infrared light by the solid-core silver halide fibers were observed for various bending angles. Percent transmission greater than 98% was consistently observed for the HWGs at the bending angles. The combined benefits of high percent transmission, reproducible instrument responses, and increased bending

  5. Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) in the thermostabilizer employed in the production of yellow-fever vaccine.

    Science.gov (United States)

    de Castro, Eduardo da S G; Cassella, Ricardo J

    2016-05-15

    Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively.

  6. Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) in the thermostabilizer employed in the production of yellow-fever vaccine.

    Science.gov (United States)

    de Castro, Eduardo da S G; Cassella, Ricardo J

    2016-05-15

    Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively. PMID:26992492

  7. Total Internal Reflection and the Related Effects

    CERN Document Server

    Kristoffel, Nikolai

    2014-01-01

    This submission presents the English translation of the early paper by N.Kristoffel appeared in Russian in the Proceedings 0f the Tartu State University No 42 p.94-112, 1956. It reflects the work done in Tartu State University (Estonia)1n 1950-s on the total internal reflection and associated effects. This paper can be of interest for the scientific community because it remained not well known during the long period. The conceptual paper of N.Kristoffel mentioned includes as the central result the prediction of the transversal shift of the totally reflected light beam.

  8. Solution to causality paradox upon total reflection

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang-min; CAO Zhuang-qi; ZHU Peng-fei; SHEN Qi-shun

    2006-01-01

    A dispute about the existence of an additional time (named as the Goos-H(a)nchen time) associated with the Goos-H(a)nchen shift in total reflection has recently arisen.At the same time,an inconsistency between the optical ray model and the electromagnetic theory also appears in the optical planar waveguide.By analyzing light propagation in an optical planar waveguide with both the zigzag-ray model and the electromagnetic theory,this paper shows that the Goos-H(a)nchen time really exists,and the total time delay upon total reflection upon an ideal nonabsorbing plasma mirror is the sum of the group-delay time and the Goos-H(a)nchen time.The causality paradox of total reflection of a TM wave upon an ideal nonabsorbing plasma mirror is also solved taking into consideration the negative Goos-H(a)nchen shift.Finally,the expression of the group velocity of the guided mode in optical planar waveguide was obtained,which clearly shows that the time delay upon total reflection is the sum of the group-delay time and the Goos-H(a)nchen time at given any time.

  9. Total internal reflection laser tools and methods

    Energy Technology Data Exchange (ETDEWEB)

    Zediker, Mark S.; Faircloth, Brian O.; Kolachalam, Sharath K.; Grubb, Daryl L.

    2016-02-02

    There is provided high power laser tools and laser heads that utilize total internal reflection ("TIR") structures to direct the laser beam along a laser beam path within the TIR structure. The TIR structures may be a TIR prism having its hypotenuse as a TIR surface.

  10. Total reflection X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    In the past few years, total reflection X-ray flourescence analysis (TXRF) has found an increasing number of assignments and applications. Experience of trace element analysis using TXRF and examples of applications are already widespread. Therefore, users of TXRF had the opportunity of an intensive exchange of their experience at the 1st workshop on total reflection X-ray fluorescence analysis which took place on May 27th and 28th 1986 at the GKSS Research Centre at Geesthacht. In a series of lectures and discussions dealing with the analytical principle itself, sample preparation techniques and applications as well as comuter programs for spectrum evaluation, the present state of development and the range of applications were outlined. 3 studies out of a total of 14 were included separately in the INIS and ENERGY databases. With 61 figs., 12 tabs

  11. Potential Modulation on Total Internal Reflection Ellipsometry.

    Science.gov (United States)

    Liu, Wei; Niu, Yu; Viana, A S; Correia, Jorge P; Jin, Gang

    2016-03-15

    Electrochemical-total internal reflection ellipsometry (EC-TIRE) has been proposed as a technique to observe the redox reactions on the electrode surface due to its high phase sensitivity to the electrolyte/electrode interface. In this paper, we mainly focus on the influence of the potential modulation on the TIRE response. The analysis suggests that both dielectric constant variation of gold and the electric double layer transformation would modulate the reflection polarization of the surface. For a nonfaradaic process, the signal of TIRE would be proportional to the potential modulation. To testify the analysis, linear sweep voltammetry and open circuit measurement have been performed. The results strongly support the system analysis. PMID:26889871

  12. Aggregated Total Internal Reflection Optics for Solar

    Science.gov (United States)

    Schultz, David; Grimmer, Chris; Fine, Kevin; Evans, Matt; Ghosh, Shondip

    2010-10-01

    An agglomeration of factors has stifled the economic promise of CPV. Foremost among these factors are: insufficient optical efficiency, misfit with existing solar infrastructure, high costs, and inadequate reliability of the optic-receiver package. These difficulties are significantly driven by the choice of optic. The CPV industry is constrained in a paradigm of bulky reflective or refractive optics that operate best at either low concentration (2-5x) or high concentration (100x and above). Low concentration approaches are plagued by marginal economics, while high concentration approaches face technical risks and do not fit well with the existing solar infrastructure. Using total internal reflection as the primary optical mechanism, a cost effective, line-focus optic can be produced at scale to provide superior optical performance in a flat profile and operate at a mid level of concentration to optimize the tradeoff between economic benefit and adoptability.

  13. Importance of Attenuating Quadriceps Activation Deficits after Total Knee Arthroplasty

    OpenAIRE

    Thomas, Abbey C.; Jennifer E Stevens-Lapsley

    2012-01-01

    Total knee arthroplasty (TKA) is associated with persistent quadriceps dysfunction. Since quadriceps dysfunction impairs functional performance, minimizing quadriceps dysfunction by attenuating central activation deficits early after surgery may improve function later in life. Rehabilitation strategies incorporating neuromuscular electrical stimulation and early, aggressive quadriceps strengthening may prove beneficial. Further, surgical approaches such as minimally invasive TKA may minimize ...

  14. Total internal reflection tomography of small objects

    International Nuclear Information System (INIS)

    The multiple signal classification (MUSIC) imaging method is applied to determine the locations of a collection of small anisotropic spherical scatterers in the framework of the total internal reflection tomography. Multiple scattering between scatterers is considered and the inverse scattering problem is nonlinear, which, however, is solved by the proposed fast analytical approach where no associated forward problem is iteratively evaluated. The paper also discusses the role of the polarization of incidence waves, the incidence angle, the separation of scatterers from the surface of the substrate, and the level of noise on the resolution of imaging.

  15. Study on Detection Methods of Interstitial Fluid Glucose Concentration Based on Infrared Attenuated Total Reflection%基于红外ATR光谱的组织液中葡萄糖信息检测方法研究

    Institute of Scientific and Technical Information of China (English)

    孙长月; 曹玉珍; 余松林; 于海霞; 徐可欣; 栗大超

    2014-01-01

    Measuring the glucose concentrations in the interstitial fluid is currently the main method to achieve the continuous blood glucose monitoring .The MIR-ATR(Mid-infrared ,Attenuated Total Reflection)Spectroscopy has prominent advantage on the analysis of small biological molecule for composition information like the glucose ,but it is still an unresolved problem that how to detect the subcutaneous glucose concentration by using the MIR-ATR Spectroscopy .In the present paper ,we carry out the experiment based on MIR-ATR for the detection of subcutaneous glucose information on both the natural state and the pene-tration state based on the theoryanalysis of MIR penetration depth .Firstly ,collect spectral data of the subcutaneous glucose con-centration of human finger on the natural state were collected as the light shined the skin directly ,and it was discussed whether the MIR can penetrate the skin to get the information of subcutaneous glucose .On this basis ,collect spectral data of the subcu-taneous glucose concentration of human finger at the penetration state were collected when the Interstitial fluid is permeated to the surface layer by using low-frequency ultrasound and vacuum ,then it analyzed that whether it can detect the glucose-specific information or not .As the two-dimensional correlation spectroscopy has high resolution and good versatility ,it is widely used to analyze the inter-molecular reaction and judge the absorption peaks information in many fields including the M IR spectroscopy field ,so we choose the Two-dimensional correlation spectroscopy to analyze the information of subcutaneous glucose concentra-tion at the natural state and the penetration state .The experiment result shows that the MIR-ATR spectroscopy can’t be applied in the detection of subcutaneous glucose concentrationdirectly ,and it is a promising direction to make the Interstitial fluid perme-ated to the surface layer by the physical methods or chemical methods .%通过测量

  16. 基于红外ATR光谱的组织液中葡萄糖信息检测方法研究%Study on Detection Methods of Interstitial Fluid Glucose Concentration Based on Infrared Attenuated Total Reflection

    Institute of Scientific and Technical Information of China (English)

    孙长月; 曹玉珍; 余松林; 于海霞; 徐可欣; 栗大超

    2014-01-01

    Measuring the glucose concentrations in the interstitial fluid is currently the main method to achieve the continuous blood glucose monitoring .The MIR-ATR(Mid-infrared ,Attenuated Total Reflection)Spectroscopy has prominent advantage on the analysis of small biological molecule for composition information like the glucose ,but it is still an unresolved problem that how to detect the subcutaneous glucose concentration by using the MIR-ATR Spectroscopy .In the present paper ,we carry out the experiment based on MIR-ATR for the detection of subcutaneous glucose information on both the natural state and the pene-tration state based on the theoryanalysis of MIR penetration depth .Firstly ,collect spectral data of the subcutaneous glucose con-centration of human finger on the natural state were collected as the light shined the skin directly ,and it was discussed whether the MIR can penetrate the skin to get the information of subcutaneous glucose .On this basis ,collect spectral data of the subcu-taneous glucose concentration of human finger at the penetration state were collected when the Interstitial fluid is permeated to the surface layer by using low-frequency ultrasound and vacuum ,then it analyzed that whether it can detect the glucose-specific information or not .As the two-dimensional correlation spectroscopy has high resolution and good versatility ,it is widely used to analyze the inter-molecular reaction and judge the absorption peaks information in many fields including the M IR spectroscopy field ,so we choose the Two-dimensional correlation spectroscopy to analyze the information of subcutaneous glucose concentra-tion at the natural state and the penetration state .The experiment result shows that the MIR-ATR spectroscopy can’t be applied in the detection of subcutaneous glucose concentrationdirectly ,and it is a promising direction to make the Interstitial fluid perme-ated to the surface layer by the physical methods or chemical methods .%通过测量

  17. Plasmonically amplified bioassay - Total internal reflection fluorescence vs. epifluorescence geometry.

    Science.gov (United States)

    Hageneder, Simone; Bauch, Martin; Dostalek, Jakub

    2016-08-15

    This paper investigates plasmonic amplification in two commonly used optical configurations for fluorescence readout of bioassays - epifluorescence (EPF) and total internal reflection fluorescence (TIRF). The plasmonic amplification in the EPF configuration was implemented by using crossed gold diffraction grating and Kretschmann geometry of attenuated total reflection method (ATR) was employed in the TIRF configuration. Identical assay, surface architecture for analyte capture, and optics for the excitation, collection and detection of emitted fluorescence light intensity were used in both TIRF and EPF configurations. Simulations predict that the crossed gold diffraction grating (EPF) can amplify the fluorescence signal by a factor of 10(2) by the combination of surface plasmon-enhanced excitation and directional surface plasmon-coupled emission in the red part of spectrum. This factor is about order of magnitude higher than that predicted for the Kretschmann geometry (TIRF) which only took advantage of the surface plasmon-enhanced excitation. When applied for the readout of sandwich interleukin 6 (IL-6) immunoassay, the plasmonically amplified EPF geometry designed for Alexa Fluor 647 labels offered 4-times higher fluorescence signal intensity compared to TIRF. Interestingly, both geometries allowed reaching the same detection limit of 0.4pM despite of the difference in the fluorescence signal enhancement. This is attributed to inherently lower background of fluorescence signal for TIRF geometry compared to that for EPF which compensates for the weaker fluorescence signal enhancement. The analysis of the inflammation biomarker IL-6 in serum at medically relevant concentrations and the utilization of plasmonic amplification for the fluorescence measurement of kinetics of surface affinity reactions are demonstrated for both EPF and TIRF readout. PMID:27260457

  18. Plasmonically amplified bioassay - Total internal reflection fluorescence vs. epifluorescence geometry.

    Science.gov (United States)

    Hageneder, Simone; Bauch, Martin; Dostalek, Jakub

    2016-08-15

    This paper investigates plasmonic amplification in two commonly used optical configurations for fluorescence readout of bioassays - epifluorescence (EPF) and total internal reflection fluorescence (TIRF). The plasmonic amplification in the EPF configuration was implemented by using crossed gold diffraction grating and Kretschmann geometry of attenuated total reflection method (ATR) was employed in the TIRF configuration. Identical assay, surface architecture for analyte capture, and optics for the excitation, collection and detection of emitted fluorescence light intensity were used in both TIRF and EPF configurations. Simulations predict that the crossed gold diffraction grating (EPF) can amplify the fluorescence signal by a factor of 10(2) by the combination of surface plasmon-enhanced excitation and directional surface plasmon-coupled emission in the red part of spectrum. This factor is about order of magnitude higher than that predicted for the Kretschmann geometry (TIRF) which only took advantage of the surface plasmon-enhanced excitation. When applied for the readout of sandwich interleukin 6 (IL-6) immunoassay, the plasmonically amplified EPF geometry designed for Alexa Fluor 647 labels offered 4-times higher fluorescence signal intensity compared to TIRF. Interestingly, both geometries allowed reaching the same detection limit of 0.4pM despite of the difference in the fluorescence signal enhancement. This is attributed to inherently lower background of fluorescence signal for TIRF geometry compared to that for EPF which compensates for the weaker fluorescence signal enhancement. The analysis of the inflammation biomarker IL-6 in serum at medically relevant concentrations and the utilization of plasmonic amplification for the fluorescence measurement of kinetics of surface affinity reactions are demonstrated for both EPF and TIRF readout.

  19. Total Internal Reflection of Orbital Angular Momentum Beams

    OpenAIRE

    Loffler W.; Hermosa N.; Aiello A.; Woerdman J.P.

    2012-01-01

    We investigate how beams with orbital angular momentum (OAM) behave under total internal reflection. This is studied in two complementary experiments: In the first experiment, we study geometric shifts of OAM beams upon total internal reflection (Goos-H\\"anchen and Imbert-Fedorov shifts, for each the spatial and angular variant), and in the second experiment we determine changes in the OAM mode spectrum of a beam, again upon total internal reflection. As a result we find that in the first cas...

  20. Multiple attenuation to reflection seismic data using Radon filter and Wave Equation Multiple Rejection (WEMR) method

    Energy Technology Data Exchange (ETDEWEB)

    Erlangga, Mokhammad Puput [Geophysical Engineering, Institut Teknologi Bandung, Ganesha Street no.10 Basic Science B Buliding fl.2-3 Bandung, 40132, West Java Indonesia puput.erlangga@gmail.com (Indonesia)

    2015-04-16

    Separation between signal and noise, incoherent or coherent, is important in seismic data processing. Although we have processed the seismic data, the coherent noise is still mixing with the primary signal. Multiple reflections are a kind of coherent noise. In this research, we processed seismic data to attenuate multiple reflections in the both synthetic and real seismic data of Mentawai. There are several methods to attenuate multiple reflection, one of them is Radon filter method that discriminates between primary reflection and multiple reflection in the τ-p domain based on move out difference between primary reflection and multiple reflection. However, in case where the move out difference is too small, the Radon filter method is not enough to attenuate the multiple reflections. The Radon filter also produces the artifacts on the gathers data. Except the Radon filter method, we also use the Wave Equation Multiple Elimination (WEMR) method to attenuate the long period multiple reflection. The WEMR method can attenuate the long period multiple reflection based on wave equation inversion. Refer to the inversion of wave equation and the magnitude of the seismic wave amplitude that observed on the free surface, we get the water bottom reflectivity which is used to eliminate the multiple reflections. The WEMR method does not depend on the move out difference to attenuate the long period multiple reflection. Therefore, the WEMR method can be applied to the seismic data which has small move out difference as the Mentawai seismic data. The small move out difference on the Mentawai seismic data is caused by the restrictiveness of far offset, which is only 705 meter. We compared the real free multiple stacking data after processing with Radon filter and WEMR process. The conclusion is the WEMR method can more attenuate the long period multiple reflection than the Radon filter method on the real (Mentawai) seismic data.

  1. Dispersion Properties in Total Internal Reflective Photonic Crystal Fiber

    Institute of Scientific and Technical Information of China (English)

    WEN Hua; HAO Dong-shan

    2004-01-01

    The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index, effective normalized frequency and dispersion management solitons. It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion. The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.

  2. Total Internal Reflection for Effectively Transparent Solar Cell Contacts

    CERN Document Server

    Jahelka, Phillip; Atwater, Harry

    2016-01-01

    A new strategy for eliminating photocurrent losses due to the metal contacts on the front of a solar cell was proposed, simulated, and tested. By placing triangular cross-section lines of low refractive index on top of the contacts, total-internal reflection at the interface of the low-index triangles and the surrounding material can direct light away from the metal and into the photoactive absorber. Simulations indicated that losses can be eliminated for any incident angle, and that yearly energy production improvements commensurate with the metallized area are possible. Proof of principle experiments were carried out to eliminate the reflective losses of a commercial solar cell's busbar contact. Spatially resolved laser beam induced current measurements demonstrated that reflection losses due to the busbar were reduced by voids with triangular cross-section.

  3. Breakthroughs in Photonics 2014: Relaxed Total Internal Reflection

    CERN Document Server

    Jahani, Saman

    2015-01-01

    Total internal reflection (TIR) is a ubiquitous phenomenon used in photonic devices ranging from waveguides and resonators to lasers and optical sensors. Controlling this phenomenon and light confinement are keys to the future integration of nanoelectronics and nanophotonics on the same silicon platform. We introduced the concept of relaxed total internal reflection in 2014 to control evanescent waves generated during TIR. These unchecked evanescent waves are the fundamental reason photonic devices are inevitably diffraction-limited and cannot be miniaturized. Our key design concept is the engineered anisotropy of the medium into which the evanescent wave extends thus allowing for skin depth engineering without any metallic components. In this article, we give an overview of our approach and compare it to key classes of photonic devices such as plasmonic waveguides, photonic crystal waveguides and slot waveguides. We show how our work can overcome a long standing issue in photonics nanoscale light confinement...

  4. Total Reflection X Ray Fluorescence: an approach to nano analysis

    International Nuclear Information System (INIS)

    Within the last decade, Total Reflection X Ray Fluorescence (TXRF) has become an extremely powerful method of element analysis. It allows nanoanalytical investigations in three different ways: (i) use of minute sample amounts of only some 100 nanograms, (i i) determination of extreme traces down to nanograms per liter and (i i i) depth profiling of near surface layers of only 10 nanometer thickness. The basic principles of TXRF are described and examples of applications are demonstrated

  5. Total Internal Reflection Accounts for the Bright Color of the Saharan Silver Ant.

    Science.gov (United States)

    Willot, Quentin; Simonis, Priscilla; Vigneron, Jean-Pol; Aron, Serge

    2016-01-01

    The Saharan silver ant Cataglyphis bombycina is one of the terrestrial living organisms best adapted to tolerate high temperatures. It has recently been shown that the hairs covering the ant's dorsal body part are responsible for its silvery appearance. The hairs have a triangular cross-section with two corrugated surfaces allowing a high optical reflection in the visible and near-infrared (NIR) range of the spectrum while maximizing heat emissivity in the mid-infrared (MIR). Those two effects account for remarkable thermoregulatory properties, enabling the ant to maintain a lower thermal steady state and to cope with the high temperature of its natural habitat. In this paper, we further investigate how geometrical optical and high reflection properties account for the bright silver color of C. bombycina. Using optical ray-tracing models and attenuated total reflection (ATR) experiments, we show that, for a large range of incidence angles, total internal reflection (TIR) conditions are satisfied on the basal face of each hair for light entering and exiting through its upper faces. The reflection properties of the hairs are further enhanced by the presence of the corrugated surface, giving them an almost total specular reflectance for most incidence angles. We also show that hairs provide an almost 10-fold increase in light reflection, and we confirm experimentally that they are responsible for a lower internal body temperature under incident sunlight. Overall, this study improves our understanding of the optical mechanisms responsible for the silver color of C. bombycina and the remarkable thermoregulatory properties of the hair coat covering the ant's body.

  6. MEASUREMENTS OF RAIN DROP SIZE DISTRBUTION FROM RADAR REFLECTIVITY AND ASSOCIATED RAIN ATTENUATION OF RADIO WAVES

    Directory of Open Access Journals (Sweden)

    A. B. Bhattacharya,

    2011-05-01

    Full Text Available Radar measurements of rainfall at different climatological conditions have been taken into account emphasizing rain rate and associated radar reflectivity. It is observed from the analysis that thereflectivity measurement is being consistent at high rain intensities. From the knowledge of radar reflectivity, the rain drop size distribution is examined. The most probable drop size diameter and rain rate have been calculated wherefrom it appears that the most probable rain drop size vary exponentially with radar reflectivity and also with rain rate. The theoretical model implemented by using the measured rain drop sizes over the tropical sites also show similar kind of variation. For estimating rain attenuation two important parameters, viz., the point rainfall rates and the vertical and horizontal structures of rain have been considered. The elevation angle we have chosen is ~ 560 as most of the stations in India havethat value of elevation angle with geostationary satellite. Taking the frequencies 11 to 14 GHz separately and 00 C isotherm height as 5.0 km, the effective rain height values are determined. The attenuation of radio waves due to rain are calculated for different rain rates assigning different γ-values. The attenuation is found to vary significantly with the γ-values. Also the attenuation curves are closer when the γ-values are of low order. An increase in attenuation with the γ-values is found to be more prominent for higher rain rates.

  7. Comment on 'Photonic tunneling time in frustrated total internal reflection'

    International Nuclear Information System (INIS)

    This is a comment on Stahlhofen's paper [Phys. Rev. A 62, 012112 (2000)]. It is shown by stationary-phase theory that the Goos-Haenchen shift in frustrated total internal reflection (FTIR) is not independent of the group delay (or phase time in the literature). The group delay involves the contribution of Goos-Haenchen shift and is always larger than zero in FTIR. It is also shown that the group delay in the two-dimensional (2D) optical FTIR can be written in the same form as that of the group delay in the 1D quantum tunneling in the sense that the group delay is the derivative of the total phase shift with respect to the angular frequency

  8. Determination of total mass attenuation coefficients, effective atomic numbers and electron densities for different shielding materials

    International Nuclear Information System (INIS)

    Highlights: • The gamma shielding properties of eight shielding materials have been investigated. • We calculated the total mass attenuation coefficients by using WinXCom program. • The values of effective atomic number and electron density are also calculated. • All parameters depend on chemical content and the incident photon energy. • The Field castable Heat Resistant is the most effective shielding material. - Abstract: In this paper, the interaction of gamma rays with some shielding materials has been studied. The total mass attenuation coefficient (μt) for eight shielding materials has been calculated by using WinXCOM program in the energy range from 1 keV to 100 GeV. Also, the effective atomic number (Zeff) and the effective electron density (Neff) were calculated using the values of the total mass attenuation coefficient. The dependence of these parameters on the incident photon energy and the chemical composition has been examined

  9. Attenuation and reflection of radio waves by a melting layer of precipitation

    NARCIS (Netherlands)

    Klaassen, W.

    1990-01-01

    Attenuation and reflection of a melting layer are calculated using a meteorological model. The model employs a new scheme for the calculation of the dielectric properties of melting ice particles with densities ranging from those of loose snow to hail, and a new scheme for calculating the melting ra

  10. Removal cross sections and total mass attenuation coefficients of fast neutrons and gamma rays for steel

    CERN Document Server

    Elsayed, A A

    2003-01-01

    The present work deals with the study of the attenuation properties and determination of the cross sections of fast neutrons and gamma rays for structure steel used in different applications in nuclear power plants, particle accelerators, research reactors and different radiation attenuation fields. Investigation has been performed by measuring the transmitted fast neutron and gamma ray spectra behind cylindrical samples of steel (rho=7.87 gem sup - sup 3) of different thicknesses. A reactor collimated beam and neutron - gamma spectrometer with stiblbene scintillator were used for measurements. The pluse shape disriminate technique based on zero cross over method was used to discriminate between neutron and gamma ray pulses. Effective removal cross-section (sigma sub R) and total mass attenuation coefficient (mu) of neureons and gamma rays have been achieved using the attenuation relations. Microscopic removal cross sections sigma sup 9 sup 8 and mass removal cross sections sigma sub R sub / subrho of fast ne...

  11. Attenuation of front-end reflections in an impulse radar using high-speed switching

    Science.gov (United States)

    Mazzaro, Gregory J.; Ressler, Marc A.; Smith, Gregory D.

    2011-06-01

    Pulse reflection between front-end components is a common problem for impulse radar systems. Such reflections arise because radio frequency components are rarely impedance-matched over an ultra-wide bandwidth. Any mismatch between components causes a portion of the impulse to reflect within the radar front-end. If the reflection couples into the transmit antenna, the radar emits an unintended, delayed and distorted replica of the intended radar transmission. These undesired transmissions reflect from the radar environment, produce echoes in the radar image, and generate false alarms in the vicinity of actual targets. The proposed solution for eliminating these echoes, without redesigning the transmit antenna, is to dissipate pulse reflections in a matched load before they are emitted. A high-speed switch directs the desired pulse to the antenna and redirects the undesired reflection from the antenna to a matched load. The Synchronous Impulse Reconstruction (SIRE) radar developed by the Army Research Laboratory (ARL) is the case-study. This paper reviews the current front-end design, provides a recent radar image which displays the aforementioned echoes, and describes the switch-cable-load circuit solution for eliminating the echoes. The consequences of inserting each portion of the new hardware into the radar front-end are explained. Measurements on the front-end with the high-speed switch show an attenuation of the undesired pulse transmissions of more than 18 dB and an attenuation in the desired pulse transmission of less than 3 dB.

  12. Frustrated total internal reflection and the illusion of superluminal propagation

    CERN Document Server

    Brudny, Vera L

    2008-01-01

    We analyze the propagation of a pulse across a vacuum gap separating opposite flat parallel faces of two transparent dielectrics by means of an explicitly causal and retarded propagator constructed directly from the free-space wave equation. Nevertheless, our approach yields apparently superluminal propagation for the case of frustrated total internal reflection (FTIR), that is, a transmitted wave packet appears on the far side of the gap at the same time that the corresponding incident packet crosses the front one. Thus, in this example superluminality is just an illusion, being consistent with both casuality and classical electrodynamics. We study the origin of the apparent superluminality in this case, which is inherent to light pulse propagation in free space and does not depend on the particulars of light-matter interaction, and find that it is due to propagation from the lateral wings of the incident pulse to the central part of the transmitted pulse. Thus, notwithstanding their similarities, FTIR is no...

  13. Single-Molecule Total Internal Reflection Fluorescence Microscopy.

    Science.gov (United States)

    Kudalkar, Emily M; Davis, Trisha N; Asbury, Charles L

    2016-01-01

    The advent of total internal reflection fluorescence (TIRF) microscopy has permitted visualization of biological events on an unprecedented scale: the single-molecule level. Using TIRF, it is now possible to view complex biological interactions such as cargo transport by a single molecular motor or DNA replication in real time. TIRF allows for visualization of single molecules by eliminating out-of-focus fluorescence and enhancing the signal-to-noise ratio. TIRF has been instrumental for studying in vitro interactions and has also been successfully implemented in live-cell imaging. Visualization of cytoskeletal structures and dynamics at the plasma membrane, such as endocytosis, exocytosis, and adhesion, has become much clearer using TIRF microscopy. Thanks to recent advances in optics and commercial availability, TIRF microscopy is becoming an increasingly popular and user-friendly technique. In this introduction, we describe the fundamental properties of TIRF microscopy and the advantages of using TIRF for single-molecule investigation. PMID:27140922

  14. Coverslip Cleaning and Functionalization for Total Internal Reflection Fluorescence Microscopy.

    Science.gov (United States)

    Kudalkar, Emily M; Deng, Yi; Davis, Trisha N; Asbury, Charles L

    2016-01-01

    Total internal reflection fluorescence (TIRF) microscopy allows visualization of biological events at the single-molecule level by restricting excitation to a precise focal plane near the coverslip and eliminating out-of-focus fluorescence. The quality of TIRF imaging relies on a high signal-to-noise ratio and therefore it is imperative to prevent adherence of molecules to the glass coverslip. Nonspecific interactions can make it difficult to distinguish true binding events and may also interfere with accurate quantification of background noise. In addition, nonspecific binding of the fluorescently tagged protein will lower the effective working concentration, thereby altering values used to calculate affinity constants. To prevent spurious interactions, we thoroughly clean the surface of the coverslip and then functionalize the glass either by applying a layer of silane or by coating with a lipid bilayer. PMID:27140911

  15. Absolute Position Total Internal Reflection Microscopy with an Optical Tweezer

    CERN Document Server

    Liu, Lulu; Rodriguez, Alejandro W; Capasso, Federico

    2014-01-01

    A non-invasive, in-situ calibration method for Total Internal Reflection Microscopy (TIRM) based on optical tweezing is presented which greatly expands the capabilities of this technique. We show that by making only simple modifications to the basic TIRM sensing setup and procedure, a probe particle's absolute position relative to a dielectric interface may be known with better than 10 nm precision out to a distance greater than 1 $\\mu$m from the surface. This represents an approximate 10x improvement in error and 3x improvement in measurement range over conventional TIRM methods. The technique's advantage is in the direct measurement of the probe particle's scattering intensity vs. height profile in-situ, rather than relying on calculations or inexact system analogs for calibration. To demonstrate the improved versatility of the TIRM method in terms of tunability, precision, and range, we show our results for the hindered near-wall diffusion coefficient for a spherical dielectric particle.

  16. 傅里叶变换红外光谱结合衰减全反射技术用于地贫筛查指标的无试剂定量分析%Fourier Transform Infrared Spectroscopy Combined with Attenuated Total Reflection Applied to Reagent-Free Quantitative Analysis of Thalassemia Screening Indicators

    Institute of Scientific and Technical Information of China (English)

    龙小丽; 刘桂松; 肖青青; 陈洁梅

    2014-01-01

    A simultaneous quantitative analysis method for the thalassemia screening indicators mean corpuscular hemoglobin (MCH) ,mean corpuscular volume (MCV) ,and hemoglobin (Hb) was developed with Fourier transform infrared (FTIR) spec-trometers and attenuated total reflection (ATR) combined with partial least squares (PLS ) .A total of 380 human peripheral blood samples were collected ,which were composed of 180 positive samples and 200 negative samples according to the criteria of hematological indicator screening for thalassemia .One hundred fifty samples (64 negative ,86 positive) were randomly selected from all samples as the validation set ,the remaining 230 samples (136 negative ,94 positive) were used as modeling samples ;and then the modeling set was further subdivided into calibration set (68 negative ,47 positive ,and 115 in total) and prediction set (68 negative ,47 positive ,and 115 in total) for 200 times .Comparison of experimental results show that the prediction effect of PLS models in mid-infrared (MIR) fingerprint region (1 600~900 cm -1 ) was significantly better those of PLS models in the full scanning region (4 000~600 cm-1 ) ,and model complexity is significantly reduced .Based on PLS model in MIR fingerprint region ,the optimal numbers of PLS factors for MCH ,MCV and Hb were 10 ,10 and 6 ,respectively ,and the root mean square error (M_SEPAve ) and the correlation coefficient (M_RP ,Ave ) of prediction in the modeling set were 2.19 pg ,0.902 for MCH , 5.13 fL ,0.898 for MCV and 8.0 g · L -1 ,0.922 for Hb ,respectively .The root mean square error (V_SEP) and the correlation coefficient (V_RP ) of prediction in the validation set were 2.22 pg ,0.900 for MCH ,5.38 fL ,0.895 for MCV and 7.7 g · L -1 , 0.929 for Hb ,respectively .The sensitivity and specificity for thalassemia screening achieved 100.0% and 95.3% ,respectively . Conclusion:FTIR/ATR spectroscopy combined with PLS method could provide a new reagent-free and rapid technique for

  17. Removal cross sections and total mass attenuation coefficients of fast neutrons and gamma rays for steel

    International Nuclear Information System (INIS)

    The present work deals with the study of the attenuation properties and determination of the cross sections of fast neutrons and gamma rays for structure steel used in different applications in nuclear power plants, particle accelerators, research reactors and different radiation attenuation fields. Investigation has been performed by measuring the transmitted fast neutron and gamma ray spectra behind cylindrical samples of steel (ρ=7.87 gem-3) of different thicknesses. A reactor collimated beam and neutron - gamma spectrometer with stiblbene scintillator were used for measurements. The pluse shape disriminate technique based on zero cross over method was used to discriminate between neutron and gamma ray pulses. Effective removal cross-section (σR) and total mass attenuation coefficient (μ) of neureons and gamma rays have been achieved using the attenuation relations. Microscopic removal cross sections σ98 and mass removal cross sections σR/ρ of fast neutrons have been evaluated based on measured results and definite energies. Also, total mass attenuation coefficients (μ/σ) of gamma rays have been evalusted and calculated using measured results and XCOM code respectively. Comparison between measured and calculated results shows a resonable agreement between the two

  18. The measurement of total mass attenuation coefficients of CoCuNi alloys

    International Nuclear Information System (INIS)

    The total mass attenuation coefficients for Co, Cu, Ni elements and CoCu, CoCuNi alloys were measured at different energies with 11.88, 13.93, 17.59, 21.09 and 26.00 keV emitted an 241Am point source using transmission arrangement. The gamma rays were counted by a Si(Li) detector with a resolution of 160 eV at 5.9 keV. Also the mass attenuation coefficients of each alloy (CoCu, CoCuNi) were estimated using mixture rule. The measured values were compared with estimated values for alloys

  19. Transmission, attenuation and reflection of shear waves in the human brain

    OpenAIRE

    Clayton, Erik H.; Guy M. Genin; Bayly, Philip V.

    2012-01-01

    Traumatic brain injuries (TBIs) are caused by acceleration of the skull or exposure to explosive blast, but the processes by which mechanical loads lead to neurological injury remain poorly understood. We adapted motion-sensitive magnetic resonance imaging methods to measure the motion of the human brain in vivo as the skull was exposed to harmonic pressure excitation (45, 60 and 80 Hz). We analysed displacement fields to quantify the transmission, attenuation and reflection of distortional (...

  20. Quo Vadis total reflection X-ray fluorescence?

    International Nuclear Information System (INIS)

    The multielement trace analytical method 'total reflection X-ray fluorescence' (TXRF) has become a successfully established method in the semiconductor industry, particularly, in the ultra trace element analysis of silicon wafer surfaces. TXRF applications can fulfill general industrial requirements on daily routine of monitoring wafer cleanliness up to 300 mm diameter under cleanroom conditions. Nowadays, TXRF and hyphenated TXRF methods such as 'vapor phase decomposition (VPD)-TXRF', i.e. TXRF with a preceding surface and acid digestion and preconcentration procedure, are automated routine techniques ('wafer surface preparation system', WSPS). A linear range from 108 to 1014 [atoms/cm2] for some elements is regularly controlled. Instrument uptime is higher than 90%. The method is not tedious and can automatically be operated for 24 h/7 days. Elements such as S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Sn, Sb, Ba and Pb are included in the software for standard peak search. The detection limits of recovered elements are between 1x1011 and 1x107 [atoms/cm2] depending upon X-ray excitation energy and the element of interest. For the determination of low Z elements, i.e. Na, Al and Mg, TXRF has also been extended but its implementation for routine analysis needs further research. At present, VPD-TXRF determination of light elements is viable in a range of 109 [atoms/cm2]. Novel detectors such as silicon drift detectors (SDD) with an active area of 5 mm2, 10 mm2 or 20 mm2, respectively, and multi-array detectors forming up to 70 mm2 are commercially available. The first SDD with 100 mm2 (!) area and integrated backside FET is working under laboratory conditions. Applications of and comparison with ICP-MS, HR-ICP-MS and SR-TXRF, an extension of TXRF capabilities with an extremely powerful energy source, are also reported

  1. Depth and Reflection Total Variation for Single Image Dehazing

    OpenAIRE

    Wang, Wei; He, Chuanjiang

    2016-01-01

    Haze removal has been a very challenging problem due to its ill-posedness, which is more ill-posed if the input data is only a single hazy image. In this paper, we present a new approach for removing haze from a single input image. The proposed method combines the model widely used to describe the formation of a haze image with the assumption in Retinex that an image is the product of the illumination and the reflection. We assume that the depth and reflection functions are spatially piecewis...

  2. Exploiting total internal reflection geometry for efficient optical modulation of terahertz light

    Science.gov (United States)

    Liu, Xudong; Parrott, Edward P. J.; Ung, Benjamin S.-Y.; Pickwell-MacPherson, Emma

    2016-10-01

    Efficient methods to modulate terahertz (THz) light are essential for realizing rapid THz imaging and communication applications. Here we report a novel THz modulator which utilizes the evanescent wave in a total internal reflection setup coupled with a conductive interface to enhance the attenuation efficiency of THz light. This approach makes it possible to achieve close to 100% modulation with a small interface conductivity of 12 mS. The frequency dependence of this technique is linked to the optical properties of the materials: a material with close to frequency independent conductivity that is also controllable will result in an achromatic modulation response, and the device performance can be optimized further by tuning the internal reflection angle. In this work, we focus on applying the technique in the terahertz frequency range. Using an LED array with a pump intensity of 475 mW/cm2 to produce carriers in a silicon wafer, we have achieved a modulation depth of up to 99.9% in a broad frequency range of 0.1 THz-0.8 THz. The required pumping power for the generation of the required free carriers is low because the sheet conductivity needed is far less than required for traditional transmission techniques. Consequently, the device can be modulated by an LED making it a very practical, low cost, and scalable solution for THz modulation.

  3. Received Power Attenuation Analysis Based on Wavelet for Reflection-Style Optical Antenna Deformations in Free-Space Laser Communications

    OpenAIRE

    Wanqing Xie; Liying Tan; Jing Ma; Yang Liu

    2011-01-01

    Diversified deformations on reflection-style optical antennas caused by processing technique and complex outer-space environment in free-space laser communications are modeled by wavelet analysis. Influence due to the deformations on received power is studied by distortion attenuation factor based on the model. Theoretical and numerical analysis shows that distortion attenuation factor increases with shift factor of the model, decreases with dilation factor of the model, and decreases with ir...

  4. Effective atomic numbers and mass attenuation coefficients of some thermoluminescent dosimetric compounds for total photon interaction

    International Nuclear Information System (INIS)

    Effective atomic numbers for total gamma-ray interaction with some selected thermoluminescent dosimetric compounds such as barium acetate, barium sulfate, calcium carbonate, calcium sulfate, calcium sulfate dihydrate, cadmium sulfate (anhydrous), cadmium sulfate, strontium sulfate, and lithium fluoride have been calculated in the 1-keV to 20-MeV energy region. Experimental mass attenuation coefficients and effective atomic numbers for these compounds at selected photon energies of 26.3, 33.2, 59.54, and 661.6 keV have been obtained from good geometry transmission measurements and compared with theoretical values. The effect of absorption edge on effective atomic numbers and its variation with energy, and nonvalidity of the Bragg's mixture rule at incident photon energies closer to the absorption edges of constituent elements of compounds are discussed

  5. A visual classroom demonstration of frustrated total internal reflection as an analogue to optical tunnelling

    Science.gov (United States)

    Salman, Rabiya; Rashid, Shama; Sabieh Anwar, Muhammad

    2013-11-01

    Frustrated total internal reflection is presented as a visually attractive and convenient classroom demonstration. Optical evanescent waves penetrating through a dielectric barrier is a classical analogue to quantum mechanical tunnelling. We use the traditional double prism arrangement to demonstrate the pickup and relaunching of the evanescent wave. Total internal reflection could be completely frustrated by the insertion of an index matching fluid.

  6. Rain Rate-Radar Reflectivity Relationship for Drop Size Distribution and Rain Attenuation Calculation of Ku Band Signals

    Directory of Open Access Journals (Sweden)

    Govardhani.Immadi

    2014-05-01

    Full Text Available With the increased demand for long distance Tele communication day by day, satellite communication system was developed. Satellite communications utilize L, C, Ku and Ka bands of frequency to fulfil all the requirements. Utilization of higher frequencies causes severe attenuation due to rain. Rain attenuation is noticeable for frequencies above 10ghz. Amount of attenuation depends on whether the operating wave length is comparable with rain drop diameter or not. In this paper the main focus is on drop size distribution using empirical methods, especially Marshall and Palmer distributions. Empirical methods deal with power law relation between the rain rate(mm/h and radar reflectivity(dBz. Finally it is discussed about the rain rate variation, radar reflectivity, drop size distribution, that is made for two rain events at K L University, Vijayawada on 4th September 2013 and on 18 th August 2013.

  7. Visco-thermal effects in acoustic metamaterials: from total transmission to total reflection and high absorption

    CERN Document Server

    Molerón, Miguel; Daraio, Chiara

    2015-01-01

    We theoretically and experimentally investigate visco-thermal effects on the acoustic propagation through metamaterials consisting of rigid slabs with subwavelength slits embedded in air. We demonstrate that this unavoidable loss mechanism is not merely a refinement, but it plays a dominant role in the actual acoustic response of the structure. Specifically, in the case of very narrow slits, the visco-thermal losses avoid completely the excitation of Fabry-Perot resonances, leading to 100% reflection. This is exactly opposite to the perfect transmission predicted in the idealised lossless case. Moreover, for a wide range of geometrical parameters, there exists an optimum slit width at which the energy dissipated in the structure can be as high as 50%. This work provides a clear evidence that visco-thermal effects are necessary to describe realistically the acoustic response of locally resonant metamaterials.

  8. An ice-sheet wide framework for englacial attenuation and basal reflection from ice penetrating radar data

    Science.gov (United States)

    Jordan, Thomas; Bamber, Jonathan; Williams, Chris; Paden, John; Siegert, Martin; Huybrechts, Philippe; Gagliardini, Olivier; Gillet-Chaulet, Fabien

    2016-04-01

    Radar-inference of the bulk material properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. Unambiguous determination of basal reflection is primarily limited by uncertainty in the spatial variation of the englacial attenuation of the radio wave. Arrhenius temperature models predict that, over the extent of an ice-sheet, the depth-averaged attenuation rate can vary by a factor of ~ 6-8. However, existing `bed-returned power' radar algorithms for basal reflection assume stationarity in the depth-averaged attenuation rate. These radar algorithms are therefore only applicable to local regions of ice-sheets, and are suspected to yield erroneous values for basal reflection. Here we introduce an automated, Greenland wide, framework for radar-inference of englacial attenuation and basal reflection. To demonstrate its efficacy we apply it to recent, (2011-2014), Operation Ice Bridge data. A central feature is the use of a prior Arrhenius temperature model to estimate the spatial variation in radar attenuation as a first guess input for the radar algorithm. Specifically, this estimate is used to test for sample regions where the assumption of stationarity is valid within some specified tolerance, and to modify the bed-returned power method for local attenuation variation within each sample region. The radar algorithm is validated in a number of different ways. Firstly, we demonstrate regions of solution convergence for two different input temperature fields; the steady-state temperature fields for the SICOPOLIS and GISM ice-sheet models. Secondly, we show that, for regions of data coverage overlap, the algorithm is repeatable for different field campaign years. Thirdly, we illustrate that, for the coverage achieved, the predicted range for the basal reflection coefficient is ~ 20 dB, which is consistent with the predicted range for the basal material interface (~15 dB) and our uncertainty estimate

  9. Optical computation based on nonlinear total reflectional optical switch at the interface

    Indian Academy of Sciences (India)

    Jianqi Zhang; Huan Xu

    2009-03-01

    A new scheme of binary half adder and full adder is proposed. It realizes a kind of all-optical computation which is based on the polarization coding technique and the nonlinear total reflectional optical switches.

  10. Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

    Energy Technology Data Exchange (ETDEWEB)

    Dhara, Sangita [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Misra, N.L., E-mail: nlmisra@barc.gov.i [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Maind, S.D. [NAA Unit of Central Forensic Science Laboratory Hyderabad at Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kumar, Sanjukta A. [Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Chattopadhyay, N. [NAA Unit of Central Forensic Science Laboratory Hyderabad at Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Aggarwal, S.K. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2010-02-15

    The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 muL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO{sub 3}/HClO{sub 4}, mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1sigma) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

  11. Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

    Science.gov (United States)

    Dhara, Sangita; Misra, N. L.; Maind, S. D.; Kumar, Sanjukta A.; Chattopadhyay, N.; Aggarwal, S. K.

    2010-02-01

    The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 μL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO 3/HClO 4, mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1 σ) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

  12. Frustrated Total Internal Reflection: Resonant and Negative Goos-H\\"anchen Shifts in Microwave Regime

    CERN Document Server

    Qu, Min

    2010-01-01

    It is well-known that the variations of Goos-H\\"anchen shifts (GHSs) are closely associated with the enengy-flux provided by evanescent states in the case of total internal reflection. However, when the frustrated internal total reflection (FTIR) is realized with a Polymethyl Methacrylate (PMMA) double-prism system operated in the microwave frequency range of 8.2 GHz to 12.4 GHz, we observe that the GH shifts for the reflected beam show periodic resonances with varying the operation frequency or the air layer thickness, which is different from the variation of the corresponding reflected energy. Moreover, in another FTIR based system introduced by a composite absorptive material slab with a two-dimensional top layer of frequency selective surface (FSS), the GHSs for reflected beam are discovered as not only resonant but also negative with the incidence of transverse electric that is TE polarized.

  13. Computed-tomography attenuation values of the peritoneum reflect the severity of peritonitis due to upper gastrointestinal perforations

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate computed tomography (CT) attenuation values of the peritoneum and to relate these values to the severity of peritonitis in patients with upper gastrointestinal tract (UGI) perforations. A total of 27 consecutive patients with UGI perforations who underwent CT and emergency laparotomy in our hospital were enrolled in this study. The CT attenuation values of the peritoneum were measured at a workstation by 2 independent investigators, and these values were analyzed in relation to the severity of illness. There were significant negative correlations between the peritoneal CT attenuation values and the sequential organ failure assessment score, acute physiology and chronic health evaluation II score, and the Mannheim peritonitis index. There was a significant negative correlation between the peritoneal CT attenuation values and the length of stay in the intensive care unit. Furthermore, patients with dysfunctions in ≥3 organs had significantly lower peritoneal CT attenuation values than those with dysfunction in ≤2 organs. In conclusion, evaluation of peritoneal CT attenuation values in peritonitis patients is simple and can be employed for objective assessment of the severity of peritonitis. (author)

  14. Dynamical measurement of refractive index distribution using digital holographic interferometry based on total internal reflection.

    Science.gov (United States)

    Zhang, Jiwei; Di, Jianglei; Li, Ying; Xi, Teli; Zhao, Jianlin

    2015-10-19

    We present a method for dynamically measuring the refractive index distribution in a large range based on the combination of digital holographic interferometry and total internal reflection. A series of holograms, carrying the index information of mixed liquids adhered on a total reflection prism surface, are recorded with CCD during the diffusion process. Phase shift differences of the reflected light are reconstructed exploiting the principle of double-exposure holographic interferometry. According to the relationship between the reflection phase shift difference and the liquid index, two dimensional index distributions can be directly figured out, assuming that the index of air near the prism surface is constant. The proposed method can also be applied to measure the index of solid media and monitor the index variation during some chemical reaction processes. PMID:26480394

  15. Detection of Citrus Huanglongbing by Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR) Spectroscopy

    Science.gov (United States)

    Citrus Huanglongbing (HLB, also known as citrus greening disease) was discovered in Florida in 2005 and is spreading rapidly amongst the citrus growing regions of the state. Detection via visual symptoms of the disease is not a long term viable option. New techniques are being developed to test fo...

  16. Correcting attenuated total reflection-fourier transform infrared spectra for water vapor and carbon dioxide

    DEFF Research Database (Denmark)

    Bruun, Susanne Wrang; Kohler, Achim; Adt, Isabelle;

    2006-01-01

    Fourier transform infrared (FT-IR) spectroscopy is a valuable technique for characterization of biological samples, providing a detailed fingerprint of the major chemical constituents. However, water vapor and CO(2) in the beam path often cause interferences in the spectra, which can hamper...... an absorption band from either water vapor or CO(2). From two calibration data sets, gas model spectra were estimated in each of the four spectral regions, and these model spectra were applied for correction of gas absorptions in two independent test sets (spectra of aqueous solutions and a yeast biofilm (C...

  17. An Attenuated Total Reflectance Sensor for Copper: An Experiment for Analytical or Physical Chemistry

    Science.gov (United States)

    Shtoyko, Tanya; Zudans, Imants; Seliskar, Carl J.; Heineman, William R.; Richardson, John N.

    2004-01-01

    A sensor experiment which can be applied to advanced undergraduate laboratory course in physical or analytical chemistry is described along with certain concepts like the demonstration of chemical sensing, preparation of thin films on a substrate, microtitration, optical determination of complex ion stoichiometry and isosbestic point. It is seen…

  18. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic analysis of regenerated bone

    Science.gov (United States)

    Benetti, Carolina; Kazarain, Sergei G.; Alves, Marco A. V.; Blay, Alberto; Correa, Luciana; Zezell, Denise M.

    2014-03-01

    The cutting of bone is routinely required in medical procedures, especially in dental applications. In such cases, bone regeneration and new bone quality can determine the success of the treatment. This study investigated the main spectral differences of undamaged and healed bone using the ATR-FTIR spectroscopy technique. Three rabbits were submitted to a surgical procedure; a small piece of bone (3x3 mm2) was removed from both sides of their jaws using a high speed drill. After 15 days, the rabbits were euthanized and the jaws were removed. A bone slice was cut from each side of the jaw containing regions of undamaged and newly formed bone, resulting in six samples which were polished for spectroscopic comparison. The samples were analyzed by FTIR spectroscopy using a diamond ATR accessory. Spectral characteristics were compared and particular attention was paid to the proportion of phosphate to amide I bands and the width of the phosphate band. The results show that the ratio of phosphate to amide I is smaller in new bone tissue than in the undamaged bone, indicating a higher organic content in the newly formed bone. The analysis of the width of the phosphate band suggests a crystallinity difference between both tissues, since the width was higher in the new bone than in the natural bone. These results suggest that the differences observed in bone aging processes by FTIR spectroscopic can be applied to the study of healing processes.

  19. X-Ray Measurements Of Total Reflectivity And Scattering From Au-Coated Foils

    DEFF Research Database (Denmark)

    Hornstrup, Allan; Christensen, Finn Erland; Schnopper, H. W.

    1989-01-01

    We present X-ray measurements of total reflectivity and scattering from gold coated foils. The foils are two sorts of 0.3 mm thick dip-lacquered aluminum, 0.125 mm thick plastic (Upilex) and 0.5 mm thick dip-lacquered nickel. The analysis of the data show a high reflectivity for all but the plast...... foil, and only small microroughness (-10A at lengthscales below -0.1 micron), evidenced by low resolution scat-tering measurements....

  20. Monte Carlo simulation applied in total reflection x-ray fluorescence: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Meira, Luiza L. C.; Inocente, Guilherme F.; Vieira, Leticia D.; Mesa, Joel [Departamento de Fisica e Biofisica - Instituto de Biociencias de Botucatu, Universidade Estadual Paulista Julio de Mesquita Filho (Brazil)

    2013-05-06

    The X-ray Fluorescence (XRF) analysis is a technique for the qualitative and quantitative determination of chemical constituents in a sample. This method is based on detection of the characteristic radiation intensities emitted by the elements of the sample, when properly excited. A variant of this technique is the Total Reflection X-ray Fluorescence (TXRF) that utilizes electromagnetic radiation as excitation source. In total reflection of X-ray, the angle of refraction of the incident beam tends to zero and the refracted beam is tangent to the sample support interface. Thus, there is a minimum angle of incidence at which no refracted beam exists and all incident radiation undergoes total reflection. In this study, we evaluated the influence of the energy variation of the beam of incident x-rays, using the MCNPX code (Monte Carlo NParticle) based on Monte Carlo method.

  1. Total-reflection X-ray fluorescence analysis of Austrian wine

    International Nuclear Information System (INIS)

    The concentration of major, minor and trace elements in Austrian wine was determined by total-reflection X-ray fluorescence using gallium as internal standard. A multi-elemental analysis was possible by pipetting 6 μl of wine directly on the reflector and drying. Total-reflection X-ray fluorescence analysis was performed with Atomika EXTRA II A (Cameca) X-rays from a Mo tube with a high-energy cut-off at 20 keV in total-reflection geometry. The results showed that it was possible to identify only by the elemental analysis as fingerprint the vineyards and year of vintage among 11 different wines

  2. Analysis of archaeological ceramics by total-reflection X-ray fluorescence: Quantitative approaches

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Ruiz, R. [Servicio Interdepartamental de Investigacion, Facultad de Ciencias, Universidad Autonoma de Madrid, Modulo C-9, Laboratorio de TXRF, Crta. Colmenar, Km 15, Cantoblanco, E-28049, Madrid (Spain)], E-mail: ramon.fernandez@uam.es; Garcia-Heras, M. [Grupo de Arqueometria de Vidrios y Materiales Ceramicos, Instituto de Historia, Centro de Ciencias Humanas y Sociales, CSIC, C/ Albasanz, 26-28, 28037 Madrid (Spain)

    2008-09-15

    This paper reports the quantitative methodologies developed for the compositional characterization of archaeological ceramics by total-reflection X-ray fluorescence at two levels. A first quantitative level which comprises an acid leaching procedure, and a second selective level, which seeks to increase the number of detectable elements by eliminating the iron present in the acid leaching procedure. Total-reflection X-ray fluorescence spectrometry has been compared, at a quantitative level, with Instrumental Neutron Activation Analysis in order to test its applicability to the study of this kind of materials. The combination of a solid chemical homogenization procedure previously reported with the quantitative methodologies here presented allows the total-reflection X-ray fluorescence to analyze 29 elements with acceptable analytical recoveries and accuracies.

  3. Total reflection and cloaking by zero index metamaterials loaded with rectangular dielectric defects

    KAUST Repository

    Wu, Ying

    2013-05-06

    In this work, we investigate wave transmission property through a zero index metamaterial (ZIM) waveguide embedded with rectangular dielectric defects. We show that total reflection and total transmission (cloaking) can be achieved by adjusting the geometric sizes and/or permittivities of the defects. Our work provides another possibility of manipulating wave propagation through ZIM in addition to the widely studied dielectric defects with cylindrical geometries.

  4. Resonant tunneling effect in one-dimensional twinned lattice photonic crystal under total reflection conditions

    Science.gov (United States)

    Feng, Xi; Li, Hu; Yuxia, Tang

    2016-07-01

    Under total reflection conditions, it typically seems as though light waves will be reflected completely on the interface; in actuality, the waves can penetrate the medium as evanescent waves. In this paper, we present a twinned lattice photonic crystal with a unit cell composed of AB layers and their mirror. We assume that the refractive index n 0 of the input and output end is equal to n B and larger than n A . We first demonstrate the dependence of band structure on the incidence angle and normalized wavelength, in which the resonant tunneling bands are exposed. We then draw a comparison of bands between ABBA and AB. To conclude, we discuss the resonant tunneling effect in the twinned lattice photonic crystal under the total reflection conditions. As incidence angle increases, the resonant tunneling band ultimately vanishes completely.

  5. MONTE CARLO CALCULATION FOR CALIBRATION FUNCTIONS IN TOTAL REFLECTION X—RAY FLUORESCENCE SPECTROMETRY

    Institute of Scientific and Technical Information of China (English)

    范钦敏; 刘亚雯; 等

    1995-01-01

    Simulation approach includes such processes as photon emissions from X-ray tube with a spectral distribution,total reflection on the sample support,photoelectric effect in thin layer sample,as well as characteristic line absorption and detection,The calculation results are in agreement with experimental ones.

  6. Optical Waveguide Switches Employing Total-Internal-Reflection (TIR) Effect (Invited Paper)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, our recent research work on the total-internal-reflection optical switch is presented. The thermo-optic effect of polymeric materials and the photon-induced carrier effect of GaAlAs/GaAs are used in our devices.

  7. Nondestructive Determination of Total Chlorophyll Content in Maize Using Three-Wavelength Diffuse Reflectance

    Science.gov (United States)

    Gu, D.-D.; Wang, W.-Z.; Hu, J.-D.; Zhang, X.-M.; Wang, J.-B.; Wang, B.-S.

    2016-09-01

    Chlorophyll in leaves plays a vital role in plant growth and can be used as an indicator of a plant's nutritional status. In this paper, an experimental setup for measuring total chlorophyll content using three-wavelength diffuse reflectance is proposed, for which light-emitting diodes with peak wavelengths of 640, 660, and 940 nm are used. Two different maize strains, Zhengdan-958 and Xundan-20, fertilized at different levels before the jointing stage, were used to validate this setup. Regression analyses between remission function values of diffuse reflectance and SPAD values, as well as remission function values of diffuse reflectance and the actual total chlorophyll content, were performed. The determination coefficients between remission function values and the actual total chlorophyll content were 0.9766 for Zhengdan-958 leaves and 0.9612 for Xundan-20 leaves. The experimental results validated the feasibility of using the diffuse reflectance spectrum to determine the total chlorophyll content. This paper also provides guidance for the development of a portable instrument to determine the actual chlorophyll content.

  8. X-ray measurements of total reflectivity and scattering from Au-coated foils

    DEFF Research Database (Denmark)

    Hornstrup, Allan; Christensen, Finn Erland; Jespersen, Ellen;

    1990-01-01

    We present x-ray measurements of total reflectivity and scattering from gold-coated foils. The foils are two sorts of 0.3 mm thick dip-lacquered aluminum, 0.125 mm thick plastic (Upilex) and 0.5 mm thick dip-lacquered nickel. The analysis of the data shows a high reflectivity for all but the plas...... but the plastic foil, and only small microroughness (∼15 Å at length scales below ∼0.1 μm), evidenced by low resolution scattering measurements....

  9. Super hydrophobic surface of polytetrafluoroethylene fabricated by picosecond laser and phenomenon of total internal reflection underwater

    Science.gov (United States)

    Jiang, Yijian; Cao, Wenshen; Zhao, Yan; Wu, Yan; Ji, Lingfei

    2015-03-01

    A groove-shaped array with average 25 μm interval, 25 μm wall thickness, 75 μm depth and a columnar array with average 30 μm side length, 25 μm interval, 43 μm depth are processed by 1064 nm picosecond laser on polytetrafluoroethylene (PTFE) surface at room temperature. The water contact angle of modified PTFE surface can reach 167°, which show super hydrophobic surface of PTFE is prepared. It is observed super hydrophobic surface reflects metal luster underwater through the glassware when super hydrophobic PTFE entirely immerses in pure water. The experiment conducts super hydrophobic surface will enhance intensity of reflection of visible light underwater, which is due to total internal reflection of super hydrophobic surface und erwater.

  10. Characterization of structure of surface and interface of matter using X-ray total reflection phenomenon

    International Nuclear Information System (INIS)

    A total reflection x-ray surface analysis makes possible to practice the structure analysis of surface of matter under the atmosphere. In this paper, the principle, equipments and the examples of measurements are explained. As the application of new X-ray structure analysis method, the determination of very accurate surface number density by the anomalous grazing X-ray reflectometry (AGXR) developed by us and the X-ray scattering apparatus to study the surface and interface of liquid are explained. The number densities of Cr and Fe atom in the passive film on the surface of stainless steel are 11.8 ± 0.4 and 7.4 ± 0.3 atoms/nm3, respectively. The reflection curve of water/mercury interface can be measured and the difference of reflectance from that of the free surface of mercury was found. (J.P.N.)

  11. Total reflection X-Ray Fluorescence in medicine. Technique and applications

    International Nuclear Information System (INIS)

    The developments Total reflection X-Ray Fluorescence techniques is make the method appropriate for sample, accurate and precise analysis of heavy element in organic fluid and tissue in health related and pollutions problems, Application include analysis as an advantageous aid in drug synthesis and characterization, trace elements determination in amniotic fluid in fetus malformation studies, analysis of brain specimens and cerebrospinal fluid in central nervous system disorders, the influence of trace elements in cataract genesis and blood, body fluids and tissue drug level- monitoring. Accuracy, precision and detection limits attained in the analysis of platinum in minute amounts of serum from oncological pediatric patients undergoing chemotherapy which Pt-containing drugs shows Total reflection X-Ray Fluorescence could be used for routine analysis as an aid in clinical practice

  12. Design of plasmonic nano-antenna for total internal reflection fluorescence microscopy.

    Science.gov (United States)

    Lee, Eun-Khwang; Song, Jung-Hwan; Jeong, Kwang-Yong; Seo, Min-Kyo

    2013-10-01

    We propose a gold modified bow-tie plasmonic nano-antenna, which can be suitably used in combination with total internal reflection fluorescence microscopy. The plasmonic nano-antenna, supporting well-separated multiple resonances, not only concentrates the total internal reflection evanescent field at the deep subwavelength scale, but also enhances fluorescence emission by the Purcell effect. Finite-difference time-domain computations show that the enhancement of the excitation light strongly correlates with the far-field radiation pattern radiated from the antenna. Depending on the antenna geometry, the resonant modes are widely tuned and their wavelengths can be easily matched to the diverse emission or excitation wavelengths of fluorophores. PMID:24104219

  13. Efficient optical path folding by using multiple total internal reflections in a microcavity

    CERN Document Server

    Shinohara, Susumu; Fukushima, Takehiro; Harayama, Takahisa; Arai, Kenichi; Yoshimura, Kazuyuki

    2014-01-01

    We propose using an asymmetric resonant microcavity for the efficient generation of an optical path that is much longer than the diameter of the cavity. The path is formed along a star polygonal periodic orbit within the cavity, which is stable and confined by total internal reflection. We fabricated a semiconductor device based on this idea with an average diameter of 0.3 mm, and achieved a path length of 2.79 mm experimentally.

  14. Variable-angle total internal reflection fluorescence microscopy of intact cells of Arabidopsis thaliana

    OpenAIRE

    Kim Myung K; Hao Huaiqin; Fan Lusheng; Ash William M; Wan Yinglang; Lin Jinxing

    2011-01-01

    Abstract Background Total internal reflection fluorescence microscopy (TIRFM) is a powerful tool for observing fluorescently labeled molecules on the plasma membrane surface of animal cells. However, the utility of TIRFM in plant cell studies has been limited by the fact that plants have cell walls, thick peripheral layers surrounding the plasma membrane. Recently, a new technique known as variable-angle epifluorescence microscopy (VAEM) was developed to circumvent this problem. However, the ...

  15. Investigation And Application Of The Frustrated-Total-Internal-Reflection Phenomenon in Optical Fibers

    OpenAIRE

    Rahnavardy, K.; Arya, Vivek; Wang, A.; Weiss, J.M.

    1997-01-01

    A detailed investigation of the frustrated-total-internal-reflection (FTIR) phenomenon in silica-glass-based optical fibers and its application to simple intensity-modulated strain and pressure sensors is presented. Such sensors may be readily fabricated with silica-based fibers and can be easily modified with sapphire fibers for high-temperature industrial applications where conventional silica-based fiber sensors are not feasible. We present the all-fiber FTIR sensor and show good correlati...

  16. Wave reflection in a reaction-diffusion system: breathing patterns and attenuation of the echo.

    Science.gov (United States)

    Tsyganov, M A; Ivanitsky, G R; Zemskov, E P

    2014-05-01

    Formation and interaction of the one-dimensional excitation waves in a reaction-diffusion system with the piecewise linear reaction functions of the Tonnelier-Gerstner type are studied. We show that there exists a parameter region where the established regime of wave propagation depends on initial conditions. Wave phenomena with a complex behavior are found: (i) the reflection of waves at a growing distance (the remote reflection) upon their collision with each other or with no-flux boundaries and (ii) the periodic transformation of waves with the jumping from one regime of wave propagation to another (the periodic trigger wave).

  17. Determination of total mass attenuation coefficients, effective atomic numbers and electron densities for different shielding materials used in radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Almeida J, A. T. [FUNDACENTRO, Centro Regional de Minas Gerais, Brazilian Institute for Safety and Health at Work, Belo Horizonte, 30180-100 Minas Gerais (Brazil); Nogueira, M. S. [Center of Development of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Santos, M. A. P., E-mail: mnogue@cdtn.br [Regional Center for Nuclear Science / CNEN, 50.740-540 Recife, Pernambuco (Brazil)

    2015-10-15

    Full text: In this paper, the interaction of X-rays with some shielding materials has been studied for materials containing different amounts of barite and aggregates. The total mass attenuation coefficient (μ{sub t}) for three shielding materials has been calculated by using WinXCOM program in the energy range from RQR qualities (RQR-4, RQR-6, RQR-9, and RQR-10). They were: cream barite (density 2.99 g/cm{sup 3} collected in the State of Sao Paulo), purple barite (density 2.95 g/cm{sup 3} collected in the State of Bahia) and white barite (density 3.10 g/cm{sup 3} collected in the State of Paraiba). The chemical analysis was carried out by an X-ray fluorescence spectrometer model EDX-720, through dispersive energy. The six elements of the higher concentration found in the sample and analyzed by Spectrophotometry of Energy Dispersive X-ray for the samples were Ba(60.9% - white barite), Ca(17,92% - cream barite), Ce(3,60% - white barite), Fe(17,16% - purple barite), S(12,11% - white barite) and Si(29,61% - purple barite). Also, the effective atomic number (Z{sub eff}) and the effective electron density (N{sub eff}) were calculated using the values of the total mass attenuation coefficient. The dependence of these parameters on the incident photon energy and the chemical composition has been examined. (Author)

  18. Total Glucosides of Danggui Buxue Tang Attenuate BLM-Induced Pulmonary Fibrosis via Regulating Oxidative Stress by Inhibiting NOX4

    Directory of Open Access Journals (Sweden)

    Ping Zhao

    2015-01-01

    Full Text Available Pulmonary fibrosis (PF is a serious chronic lung disease with unknown pathogenesis. Researches have confirmed that oxidative stress which is regulated by NADPH oxidase-4 (NOX4, a main source of reactive oxygen species (ROS, is an important molecular mechanism underlying PF. Previous studies showed that total glucosides of Danggui Buxue Tang (DBTG, an extract from a classical traditional Chinese herbal formula, Danggui Buxue Tang (DBT, attenuated bleomycin-induced PF in rats. However, the mechanisms of DBTG are still not clear. We hypothesize that DBTG attenuates PF through regulating the level of oxidative stress by inhibiting NOX4. And we found that fibrosis indexes hydroxyproline (HYP and type I collagen (Col-I were lower in DBTG groups compared with the model group. In addition, the expression of transforming growth factor-β1 (TGF-β1 and expression of alpha smooth muscle actin (α-SMA were also much more decreased than the model group. For oxidative stress indicators, DBTG blunted the decrease of superoxide dismutase (SOD activity, total antioxidant capacity (T-AOC, and the increase in malondialdehyde (MDA, 8-iso-prostaglandin in lung homogenates. Treatment with DBTG restrained the expression of NOX4 compared to the model group. Present study confirms that DBTG inhibits BLM-induced PF by modulating the level of oxidative stress via suppressing NOX4.

  19. Determination of total mass attenuation coefficients, effective atomic numbers and electron densities for different shielding materials used in radiation protection

    International Nuclear Information System (INIS)

    Full text: In this paper, the interaction of X-rays with some shielding materials has been studied for materials containing different amounts of barite and aggregates. The total mass attenuation coefficient (μt) for three shielding materials has been calculated by using WinXCOM program in the energy range from RQR qualities (RQR-4, RQR-6, RQR-9, and RQR-10). They were: cream barite (density 2.99 g/cm3 collected in the State of Sao Paulo), purple barite (density 2.95 g/cm3 collected in the State of Bahia) and white barite (density 3.10 g/cm3 collected in the State of Paraiba). The chemical analysis was carried out by an X-ray fluorescence spectrometer model EDX-720, through dispersive energy. The six elements of the higher concentration found in the sample and analyzed by Spectrophotometry of Energy Dispersive X-ray for the samples were Ba(60.9% - white barite), Ca(17,92% - cream barite), Ce(3,60% - white barite), Fe(17,16% - purple barite), S(12,11% - white barite) and Si(29,61% - purple barite). Also, the effective atomic number (Zeff) and the effective electron density (Neff) were calculated using the values of the total mass attenuation coefficient. The dependence of these parameters on the incident photon energy and the chemical composition has been examined. (Author)

  20. TX 2000: total reflection and 45o energy dispersive x-ray fluorescence spectrometer

    International Nuclear Information System (INIS)

    This equipment, developed by Ital Structures, combines two kinds of energy dispersive X-ray fluorescence techniques, the first using total reflection geometry and the second conventional 45o geometry. The equipment is completely controlled by a PC and to reach the condition of total reflection is very easy because it is enough to load the file with the right position for the corresponding energy. In this apparatus we used an x-ray tube with an alloy anode of Mo/W with a long fine focus at 2200 W. To monochromatize the x-ray beam while choosing, for example, the Mo K alpha or W L alpha or a piece of white spectrum of 33 keV, we use a highly reflective multilayer made of Si/W with 2d = 45.5 Ao. The detector used in the equipment is a lithium drifted silicon detector (Si(Li)) with an excellent energy resolution of 135 eV at 5.9 keV and 1000 cps. We developed two programs written in Windows 95, 98 and NT for a 32 bit microprocessor. The first one is called TYACQ32 and has the following functions: first, complete control of the hardware, second automatic alignment of the TX 2000 spectrometer and third acquisition of spectra. The second program is EDXRF32. This is a program to accomplish spectrum and quantitative analysis for TXRF and EDXRF 45o degrees analysis. (author)

  1. Total internal reflection optical switch using the reverse breakdown of a pn junction in silicon.

    Science.gov (United States)

    Kim, Jong-Hun; Park, Hyo-Hoon

    2015-11-01

    We demonstrate a new type of silicon total-internal-reflection optical switch with a simple pn junction functioning both as a reflector and a heater. The reflector is placed between asymmetrically y-branched multimode waveguides with an inclination angle corresponding to half of the branch angle. When the reflector is at rest, incident light is reflected in accordance to the refractive index difference due to the plasma dispersion effect of the pre-doped carriers. Switching to the transmission state is attained under a reverse breakdown of the pn junction by the thermo-optic effect which smears the refractive index difference. From this switching scheme, we confirmed the switching operation with a shallow total-internal-reflection region of 1 μm width. At a 6° branch angle, an extinction ratio of 12 dB and an insertion loss of -4.2  dB are achieved along with a thermal heating power of 151.5 mW.

  2. Total-internal-reflection-based photomask for large-area photolithography

    Science.gov (United States)

    Hung, Shao-Kang; Lin, Kung-Hsuan; Chen, Cheng-Lung; Chou, Chen-Hsun; Lin, You-Chuan

    2016-05-01

    Photolithography has been widely implemented with a photomask in contact or in close proximity to the photoresist layer. The flatness of the substrates is a crucial factor to guarantee the quality of the entire patterned photoresist (PR) layer especially for large-area photolithography. However, some substrates, such as sapphire wafers, do not possess highly uniform thickness as silicon wafer does. In this work, we demonstrate that a flexible polydimethylsiloxane (PDMS) photomask with optical total-internal-reflection structure can effectively circumvent this problem for mass production. Different from conventional photomask that the light is blocked by the patterned reflective/absorbing materials, the distributions of light intensity on the PR is engineered by the geometric structure of the transparent PDMS photomask. We demonstrate that 4 in. patterned sapphire wafers can be successfully fabricated by using this PDMS photomask, which can be easily integrated into the present techniques in industry for mass production of substrates for GaN-based optoelectronic devices.

  3. Attenuation fluctuations and local dermal reflectivity are indicators of immune cell infiltrate and epidermal hyperplasia in skin inflammation

    Science.gov (United States)

    Phillips, Kevin G.; Wang, Yun; Choudhury, Niloy; Levitz, David; Swanzey, Emily; Lagowski, James; Kulesz-Martin, Molly; Jacques, Steven

    2012-02-01

    Psoriasis is a common inflammatory skin disease resulting from genetic and environmental alterations of cutaneous immune responses responsible for skin homeostasis. While numerous therapeutic targets involved in the immunopathogenesis of psoriasis have been identified, the in vivo dynamics of psoriasis remains under investigated. To elucidate the spatial-temporal morphological evolution of psoriasis we undertook in vivo time course focus-tracked optical coherence tomography (OCT) imaging to non-invasively document dermal alterations due to immune cell infiltration and epidermal hyperplasia in an Imiquimod (IMQ) induced model of psoriasis-like inflammation in DBA2/C57Bl6 hybrid mice. Quantitative appraisal of dermal architectural changes was achieved through a three parameter fit of OCT axial scans in the dermis of the form A(z) = ρ exp(-mu;z +ɛ(z)). Ensemble averaging of the fit parameters over 2000 axial scans per mouse in each treatment arm revealed that the local dermal reflectivity ρ, decreased significantly in response to 6 day IMQ treatment (p = 0.0001), as did the standard deviation of the attenuation fluctuation std(ɛ(z)), (p = 0.04), in comparison to cream controls and day 1 treatments. No significant changes were observed in the average dermal attenuation rate, μ. Our results suggest these label-free OCT-based metrics can be deployed to investigate new therapeutic targets in animal models as well as aid in clinical staging of psoriasis in conjunction with the psoriasis area and severity index.

  4. Integrated optic polarization splitter based on total internal reflection from a birefringent polymer.

    Science.gov (United States)

    Huang, Guanghao; Park, Tae-Hyun; Chu, Woo-Sung; Oh, Min-Cheol

    2016-09-01

    An integrated optic polarization splitter with large fabrication tolerance and high reliability is required for optical signal processing in quantum-encrypted communication systems. A polarization splitter based on total internal reflection from a highly birefringent polymer-reactive mesogen-is proposed and demonstrated in this work. The device consists of a mode expander for reducing the wave vector distribution of the guided mode, and an interface with a large birefringence. Several polymers with suitable refractive indexes were used for fabricating the device. We obtained a polarization splitter with a low crosstalk (less than -30 dB), and a large fabrication tolerance. PMID:27607704

  5. Frustrated total internal reflection and critical coupling in a thick plasmonic grating with narrow slits

    International Nuclear Information System (INIS)

    We demonstrate the possibility of critical coupling through frustrated total internal reflection in a thick plasmonic grating below the first diffraction order. Differently from conventional approaches relying on the excitation of surface plasmon-polaritons, here we exploit the light coupling with the leaky modes supported by the grating. This mechanism entails a wide-angle coupling and effectively access spectral bands that would otherwise be difficult to probe using conventional plasmonic critical coupling techniques, such as the Otto configuration. Our finding may pave the way to efficient plasmonic bio-sensor devices.

  6. Microplate-compatible total internal reflection fluorescence microscopy for receptor pharmacology

    Science.gov (United States)

    Chen, Minghan; Zaytseva, Natalya V.; Wu, Qi; Li, Min; Fang, Ye

    2013-05-01

    We report the use of total internal reflection fluorescence (TIRF) microscopy for analyzing receptor pharmacology and the development of a microplate-compatible TIRF imaging system. Using stably expressed green fluorescence protein tagged β2-adrenergic receptor as the reporter, we found that the activation of different receptors results in distinct kinetic signatures of the TIRF intensity of cells. These TIRF signatures closely resemble the characteristics of their respective label-free dynamic mass redistribution signals in the same cells. This suggests that TIRF in microplate can be used for profiling and screening drugs.

  7. Frustrated total internal reflection and critical coupling in a thick plasmonic grating with narrow slits

    Energy Technology Data Exchange (ETDEWEB)

    Mattiucci, N.; D' Aguanno, G., E-mail: gdaguanno@aegistg.com, E-mail: giuseppe.daguanno@us.army.mil [AEgis Technologies, Inc., 410 Jan Davis Dr, Huntsville, Alabama 35806 (United States); Bloemer, M. J. [Department of the Army, C. M. Bowden Laboratory, Redstone Arsenal, Alabama 35898 (United States); Alù, A. [Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2014-06-02

    We demonstrate the possibility of critical coupling through frustrated total internal reflection in a thick plasmonic grating below the first diffraction order. Differently from conventional approaches relying on the excitation of surface plasmon-polaritons, here we exploit the light coupling with the leaky modes supported by the grating. This mechanism entails a wide-angle coupling and effectively access spectral bands that would otherwise be difficult to probe using conventional plasmonic critical coupling techniques, such as the Otto configuration. Our finding may pave the way to efficient plasmonic bio-sensor devices.

  8. Energy dispersive X-ray fluorescence analysis with multiple total reflection

    International Nuclear Information System (INIS)

    The development of a total reflection XRF analyzer and the performance data of this instrument are described. The drastic reduction of the scattered radiation is the outstanding property of the method. Detection limits of elements and matrix effects are discussed. The competition with other methods of analysis has proven its advantages in a wide range. In addition to its multi-element features down to the picogram level, particularly its universal calibration function has turned out to be a great help in the analytical practice. (orig./RB)

  9. Clinical applications of total reflection X-Ray Fluorescence in the treatment of cancer, Preliminary results

    International Nuclear Information System (INIS)

    A simple procedure is presents in which direct irradiation of small (10 ?l) quantities of blood serum, without chemical treatment or internal standard addition, allows reliable quantification of the PT plasma level with a 300 ppb detection limit and precision of 7% (n=7) It is shown that the method allows determination of the time evolution of the drug concentration and the drug half life in the patient the results indicated the viability of an improvement in the clinical practice of chemotherapy by the routine analysis of platinum with total reflection X-Ray Fluorescence

  10. Synchrotron total reflection X-ray fluorescence at BL-16 microfocus beamline of Indus-2

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, M. K., E-mail: mktiwari@rrcat.gov.in; Singh, A. K., E-mail: mktiwari@rrcat.gov.in; Das, Gangadhar, E-mail: mktiwari@rrcat.gov.in; Chowdhury, Anupam, E-mail: mktiwari@rrcat.gov.in; Lodha, G. S., E-mail: mktiwari@rrcat.gov.in [Indus Synchrotrons Utilisation Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

    2014-04-24

    Determination of ultra trace elements is important in many disciplines both in basic and applied sciences. Numerous applications show their importance in medical science, environmental science, materials science, food processing and semiconductor industries and in maintaining the quality control of ultra pure chemicals and reagents. We report commissioning of a synchrotron based total reflection x-ray fluorescence (TXRF) facility on the BL-16 microfocus beamline of Indus-2. This paper describes the performance of the BL-16 TXRF spectrometer and the detailed description of its capabilities through examples of measured results.

  11. Synchrotron total reflection X-ray fluorescence at BL-16 microfocus beamline of Indus-2

    International Nuclear Information System (INIS)

    Determination of ultra trace elements is important in many disciplines both in basic and applied sciences. Numerous applications show their importance in medical science, environmental science, materials science, food processing and semiconductor industries and in maintaining the quality control of ultra pure chemicals and reagents. We report commissioning of a synchrotron based total reflection x-ray fluorescence (TXRF) facility on the BL-16 microfocus beamline of Indus-2. This paper describes the performance of the BL-16 TXRF spectrometer and the detailed description of its capabilities through examples of measured results

  12. Energy Flux and Density of Nonuniform Electromagnetic Waves with Total Reflection

    Science.gov (United States)

    Petrov, N. S.

    2014-07-01

    Analytic expressions are obtained for the energy flux and density of refracted nonuniform waves produced during total reflection at the boundary between two isotropic media for the general case of elliptically polarized incident light. The average values are determined as functions of the parameters of the adjoining media and the angle of incidence. The cases of linearly and circularly polarized incident waves are examined in detail. An explicit general expression relating the energy fl ux and density of these waves for arbitrarily polarized incident light is obtained.

  13. Bromine and bromide content in soils: Analytical approach from total reflection X-ray fluorescence spectrometry.

    Science.gov (United States)

    Gallardo, Helena; Queralt, Ignasi; Tapias, Josefina; Candela, Lucila; Margui, Eva

    2016-08-01

    Monitoring total bromine and bromide concentrations in soils is significant in many environmental studies. Thus fast analytical methodologies that entail simple sample preparation and low-cost analyses are desired. In the present work, the possibilities and drawbacks of low-power total reflection X-ray fluorescence spectrometry (TXRF) for the determination of total bromine and bromide contents in soils were evaluated. The direct analysis of a solid suspension using 20 mg of fine ground soil (soils (Br content range in soils = 5-40 mg kg(-1)). Information about bromide determination in soils is also possible by analyzing the Br content in water soil extracts. In this case, the TXRF analysis can be directly performed by depositing 10 μL of the internal standardized soil extract sample on a quartz glass reflector in a measuring time of 1500 s. The bromide limit of detection by this approach was 10 μg L(-1). Good agreement was obtained between the TXRF results for the total bromine and bromide determinations in soils and those obtained by other popular analytical techniques, e.g. energy dispersive X-ray fluorescence spectrometry (total bromine) and ionic chromatography (bromide). As a study case, the TXRF method was applied to study bromine accumulation in two agricultural soils fumigated with a methyl bromide pesticide and irrigated with regenerated waste water. PMID:27179429

  14. Total reflection coefficients of low-energy photons presented as universal functions

    International Nuclear Information System (INIS)

    The possibility of expressing the total particle and energy reflection coefficients of low-energy photons in the form of universal functions valid for different shielding materials is investigated in this paper. The analysis is based on the results of Monte Carlo simulations of photon reflection by using MCNP, FOTELP, and PENELOPE codes. The normal incidence of the narrow monoenergetic photon beam of the unit intensity and of initial energies from 20 keV up to 100 keV is considered, and particle and energy reflection coefficients from the plane homogenous targets of water, aluminum, and iron are determined and compared. The representations of albedo coefficients on the initial photon energy, on the probability of large-angle photon scattering, and on the mean number of photon scatterings are examined. It is found out that only the rescaled albedo coefficients dependent on the mean number of photon scatterings have the form of universal functions and these functions are determined by applying the least square method. (author)

  15. Variable-angle total internal reflection fluorescence microscopy of intact cells of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Kim Myung K

    2011-09-01

    Full Text Available Abstract Background Total internal reflection fluorescence microscopy (TIRFM is a powerful tool for observing fluorescently labeled molecules on the plasma membrane surface of animal cells. However, the utility of TIRFM in plant cell studies has been limited by the fact that plants have cell walls, thick peripheral layers surrounding the plasma membrane. Recently, a new technique known as variable-angle epifluorescence microscopy (VAEM was developed to circumvent this problem. However, the lack of a detailed analysis of the optical principles underlying VAEM has limited its applications in plant-cell biology. Results Here, we present theoretical and experimental evidence supporting the use of variable-angle TIRFM in observations of intact plant cells. We show that when total internal reflection occurs at the cell wall/cytosol interface with an appropriate angle of incidence, an evanescent wave field of constant depth is produced inside the cytosol. Results of experimental TIRFM observations of the dynamic behaviors of phototropin 1 (a membrane receptor protein and clathrin light chain (a vesicle coat protein support our theoretical analysis. Conclusions These findings demonstrate that variable-angle TIRFM is appropriate for quantitative live imaging of cells in intact tissues of Arabidopsis thaliana.

  16. Smooth and rough Proteus mirabilis lipopolysaccharides studied by total internal reflection ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Gleńska-Olender, J., E-mail: joannaglenska@wp.pl [Institute of Biology, Jan Kochanowski University, 25-406 Kielce (Poland); Świętokrzyski Biobank, Regional Science and Technology Center, 26-060 Chęciny (Poland); Dworecki, K. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Sęk, S. [Department of Chemistry, University of Warsaw, 02-093 Warsaw (Poland); Kwinkowski, M.; Kaca, W. [Institute of Biology, Jan Kochanowski University, 25-406 Kielce (Poland)

    2013-12-02

    Total internal reflection ellipsometry (TIRE), a label-free optical detection technique for studying interactions between biomolecules, was used to examine the adsorption of various forms of lipopolysaccharides (LPSs) isolated from Proteus mirabilis S1959, R110, and R45 strains on a gold surface. The thickness of the adsorbed layers was determined by TIRE, with the average values for S1959, R110, and R45 LPS layers being 78 ± 5, 39 ± 3, and 12 ± 2 nm, respectively. The thickness of LPS layers corresponds to the presence and length of O-specific parts in P. mirabilis LPS molecules. Atomic force microscopy was used as a complementary technique for visualizing lipopolysaccharides on the surface. Force measurements seem to confirm the data obtained from TIRE experiments. - Highlights: • Proteus mirabilis lipopolysaccharides were adsorbed on the gold surface. • Thickness of adsorbed layers was determined by total internal reflection ellipsometry. • Atomic force microscopy was used to visualize lipopolysaccharide build-up on gold surface. • Time is important in the evolution of biomolecular film thickness created on gold surface.

  17. Direct analysis of biological samples by total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Lue M, Marco P. [Unidad de Analisis Instrumental, Departamento de Quimica y Suelos, Decanato de Agronomia, Universidad Centro-occidental Lisandro Alvarado, Apartado Postal 4076, Cabudare 3023 (Venezuela)]. E-mail: luemerumarco@yahoo.es; Hernandez-Caraballo, Edwin A. [Instituto Venezolano-Andino para la Investigacion Quimica (IVAIQUIM), Facultad de Ciencias, Universidad de los Andes, Merida 5101 (Venezuela)

    2004-08-31

    The technique of total reflection X-ray fluorescence (TXRF) is well suited for the direct analysis of biological samples due to the low matrix interferences and simultaneous multi-element nature. Nevertheless, biological organic samples are frequently analysed after digestion procedures. The direct determination of analytes requires shorter analysis time, low reactive consumption and simplifies the whole analysis process. On the other hand, the biological/clinical samples are often available in minimal amounts and routine studies require the analysis of large number of samples. To overcome the difficulties associated with the analysis of organic samples, particularly of solid ones, different procedures of sample preparation and calibration to approach the direct analysis have been evaluated: (1) slurry sampling, (2) Compton peak standardization, (3) in situ microwave digestion, (4) in situ chemical modification and (5) direct analysis with internal standardization. Examples of analytical methods developed by our research group are discussed. Some of them have not been previously published, illustrating alternative strategies for coping with various problems that may be encountered in the direct analysis by total reflection X-ray fluorescence spectrometry.

  18. The Mixture of Salvianolic Acids from Salvia miltiorrhiza and Total Flavonoids from Anemarrhena asphodeloides Attenuate Sulfur Mustard-Induced Injury

    Directory of Open Access Journals (Sweden)

    Jianzhong Li

    2015-10-01

    Full Text Available Sulfur mustard (SM is a vesicating chemical warfare agent used in numerous military conflicts and remains a potential chemical threat to the present day. Exposure to SM causes the depletion of cellular antioxidant thiols, mainly glutathione (GSH, which may lead to a series of SM-associated toxic responses. MSTF is the mixture of salvianolic acids (SA of Salvia miltiorrhiza and total flavonoids (TFA of Anemarrhena asphodeloides. SA is the main water-soluble phenolic compound in Salvia miltiorrhiza. TFA mainly includes mangiferin, isomangiferin and neomangiferin. SA and TFA possess diverse activities, including antioxidant and anti-inflammation activities. In this study, we mainly investigated the therapeutic effects of MSTF on SM toxicity in Sprague Dawley rats. Treatment with MSTF 1 h after subcutaneous injection with 3.5 mg/kg (equivalent to 0.7 LD50 SM significantly increased the survival levels of rats and attenuated the SM-induced morphological changes in the testis, small intestine and liver tissues. Treatment with MSTF at doses of 60 and 120 mg/kg caused a significant (p < 0.05 reversal in SM-induced GSH depletion. Gene expression profiles revealed that treatment with MSTF had a dramatic effect on gene expression changes caused by SM. Treatment with MSTF prevented SM-induced differential expression of 93.8% (973 genes of 1037 genes. Pathway enrichment analysis indicated that these genes were mainly involved in a total of 36 pathways, such as the MAPK signaling pathway, pathways in cancer, antigen processing and presentation. These data suggest that MSTF attenuates SM-induced injury by increasing GSH and targeting multiple pathways, including the MAPK signaling pathway, as well as antigen processing and presentation. These results suggest that MSTF has the potential to be used as a potential therapeutic agent against SM injuries.

  19. Tunneling mode in a frustrated total internal reflection structure with hyperbolic metamaterial

    Science.gov (United States)

    Luo, Li; Li, Chaoyang; Tang, Tingting

    2016-10-01

    We study the tunneling modes in a frustrated total internal reflection (FTIR) structure with hyperbolic metamaterial (HMM). The physical mechanism of tunneling mode is analyzed by the condition of general zero average permittivity. The influence of anisotropy, loss and dispersion of HMM on tunneling modes is discussed based on simulation results. Tunneling mode merging or splitting can be realized by adjusting the thickness of air or HMM. We can also find the absorption of HMM significantly reduces the transmittance peak of tunneling mode. When a recently reported HMM of ZnAlO/ZnO multilayer is introduced in the FTIR structure, the combined action of HMM loss and dispersion brings many small tunneling modes in the angular spectrum. The tunneling mode in the proposed structure can be used to design filters and wavelength selectors which may also have applications in wavelength de-multiplexing in optical communications.

  20. Redistribution of fluorescent molecules at the solid/liquid interface with total internal reflection illumination.

    Science.gov (United States)

    Wei, Lin; Ye, Zhongju; Luo, Wenjuan; Chen, Bo; Xiao, Lehui

    2016-08-01

    Many intriguing physical and chemical processes commonly take place at the solid/liquid interface. Total internal reflection illumination, together with single molecule spectroscopy, provides a robust platform for the selective exploration of kinetic processes close the interface. With these techniques, it was observed that the distribution of Rhodamine B molecules close to a solid/liquid interface could be regulated in a photo-induced route. The laser-induced repulsion force at this interface is enough to compromise the Brownian diffusion of single molecules in a range of several hundred nanometers normal to the solid/liquid interface. This observation is fundamentally and practically interesting because moderate laser intensity is enough to initiate this repulsion effect. Therefore, it might display extensive applications in the development of photo-modulation technique with high throughput capability. PMID:27216678

  1. Goos-H\\"anchen shifts in frustrated total internal reflection studied with wave packet propagation

    CERN Document Server

    Chen, Xi; Wei, Rong-Rong; Zhang, Yan

    2009-01-01

    We have investigated that the Goos-H\\"anchen (GH) shifts in frustrated total internal reflection (FTIR) studied with wave packet propagation. In the first-order approximation of the transmission coefficient, the GH shift is exactly the expression given by stationary phase method, thus saturates an asymptotic constant in two different ways depending on the angle of incidence. Taking account into the second-order approximation, the GH shift always depends on the width of the air gap due to the modification of the beam width. It is further shown that the GH shift with second-order correction increases with decreasing the beam width at the small incidence angles, while for the large incidence angles it reveals a strong decrease with decreasing the beam width. These phenomena offers the better understanding of the tunneling delay time in FTIR.

  2. Trace element determination in amniotic fluid by total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Greaves, E.D.; Sajo-Bohus, L.; Castelli, C.; Borgerg, C. [Universidad Simon Bolivar, Caracas (Venezuela); Meitin, J.; Liendo, J.

    1995-03-01

    A new method is reported for the determination of Fe, Cu, Zn, and Br in amniotic fluid (AF) by Total Reflection X-Ray Fluorescence. The irradiation of AF samples with monochromatic X-Rays reduces the scattering background from the organic matrix and avoids the need for sample digestion. Sample manipulation is reduced to centrifuging and adding cobalt as internal standard. Lower detection limits obtained are 109, 53, 44 and 37 ppb for Fe, Cu, Zn and Br respectively. Measurement precision depends on element concentrations and can be as low as 1.5% SD. Results of the analysis of 34 AF samples from Venezuelan pregnant patients agree with previously reported ranges of Fe, Cu and Zn. Other elements observed but not quantified are Cl, K, Ca in all spectra and Pb and Sr in some of them. (author).

  3. Colouration of medieval glass bracelets studied by total reflection x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    The contents of 3d-transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) in fragments of medieval glass bracelets, found in the necropolis of Stambolovo and the castle of Mezek, Bulgaria, were determined by total reflection X-ray fluorescence (TXRF) analysis using gallium as internal standard. The samples were analysed as slurries in Triton X 114. The experimental parameters: grain size of the glass sample, concentrations of glass sample, Triton X114 and internal standard in the slurry, volume of the slurry aliquot taken for analysis, as well as the excitation time, were optimised. For method validation the certified reference material BAM-S005 Type A soda-lime glass was used. It was proven that the elements Co, Mn and Fe are responsible for colour generation in the investigated glass samples. The precision of the determinations is characterised by an RSD in the range 3–11%

  4. Topography of Cells Revealed by Variable-Angle Total Internal Reflection Fluorescence Microscopy.

    Science.gov (United States)

    Cardoso Dos Santos, Marcelina; Déturche, Régis; Vézy, Cyrille; Jaffiol, Rodolphe

    2016-09-20

    We propose an improved version of variable-angle total internal reflection fluorescence microscopy (vaTIRFM) adapted to modern TIRF setup. This technique involves the recording of a stack of TIRF images, by gradually increasing the incident angle of the light beam on the sample. A comprehensive theory was developed to extract the membrane/substrate separation distance from fluorescently labeled cell membranes. A straightforward image processing was then established to compute the topography of cells with a nanometric axial resolution, typically 10-20 nm. To highlight the new opportunities offered by vaTIRFM to quantify adhesion process of motile cells, adhesion of MDA-MB-231 cancer cells on glass substrate coated with fibronectin was examined. PMID:27653490

  5. Watch your step! A frustrated total internal reflection approach to forensic footwear imaging

    Science.gov (United States)

    Needham, J. A.; Sharp, J. S.

    2016-02-01

    Forensic image retrieval and processing are vital tools in the fight against crime e.g. during fingerprint capture. However, despite recent advances in machine vision technology and image processing techniques (and contrary to the claims of popular fiction) forensic image retrieval is still widely being performed using outdated practices involving inkpads and paper. Ongoing changes in government policy, increasing crime rates and the reduction of forensic service budgets increasingly require that evidence be gathered and processed more rapidly and efficiently. A consequence of this is that new, low-cost imaging technologies are required to simultaneously increase the quality and throughput of the processing of evidence. This is particularly true in the burgeoning field of forensic footwear analysis, where images of shoe prints are being used to link individuals to crime scenes. Here we describe one such approach based upon frustrated total internal reflection imaging that can be used to acquire images of regions where shoes contact rigid surfaces.

  6. Trace elements determination in red and white wines using total-reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    Several wines produced in different regions from south of Brazil and available in markets in Rio de Janeiro were analyzed for their contents of elements such as: P, S, Cl, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb and Sr. Multi-element analysis was possible with simple sample preparation and subsequent analysis by total-reflection X-ray fluorescence using synchrotron radiation. The measurement was carried at the X-ray fluorescence beamline in the Synchrotron Light Source Laboratory in Campinas, Brazil. The levels of the various elements obtained were lower in the Brazilian wines than the values generally found in the literature. The present study indicates the capability of multi-element analysis for determining the contents of various elements present in wines coming from Brazil vineyards by using a simple, sensitive and precise method

  7. Total reflection X-ray fluorescence analysis of airborne particulate matter

    Energy Technology Data Exchange (ETDEWEB)

    Klockenkaemper, R.; Bayer, H.; Bohlen, A. von [Institut fuer Spektrochemie und Angewandte Spektroskopie, Dortmund (Germany)

    1995-03-01

    The collection of air dust by a `Berner`- and a `Battelle`-impactor was adapted to the subsequent analysis by Total reflection X-Ray Fluorescence (TXRF). A suitable impactor material has to be chosen in order to avoid high blank values, collection losses and memory effects. Stainless steel even coated by TiN is not at all suitable. Titanium and aluminium are less favourable than makrolon or another high polymer which may even be antistatic. Small sampling volumes of only 1 m{sup 3} and short sampling times of about 1 h are sufficient for a multielement analysis by TXRF. Low detection limits of ng/m{sup 3} and a repeatability of some % can be realized. (author).

  8. Observation of Insulin Exocytosis by a Pancreatic (3 Cell Line with Total Internal Reflection Fluorescence Microscopy

    Institute of Scientific and Technical Information of China (English)

    Zhao-ying Fu; Ya-ping Wang; Yu Chen

    2011-01-01

    @@ INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radio-immunoassay.However,these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis.In recent years,an imaging technique known as total internal reflection fluorescence (TIRF) microscopy has been employed to study insulin secretion.1-4 This imaging technique can explore events taking place near or on live cell membrane,such as secretory granule movement,exocytosis,vesicle content release,and membrane fusion.5-10 In the present paper,we applied TIRF microscopy to the observation of insulin exocytosis by the pancreatic β cell line Ins-1.

  9. First Total Reflection X-Ray Fluorescence round-robin test of water samples: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Borgese, Laura; Bilo, Fabjola [Chemistry for Technologies Laboratory, University of Brescia, Brescia (Italy); Tsuji, Kouichi [Graduate School of Engineering, Osaka City University, Osaka (Japan); Fernández-Ruiz, Ramón [Servicio Interdepartamental de Investigación (SIdI), Laboratorio de TXRF, Universidad Autónoma de Madrid, Madrid (Spain); Margui, Eva [Department of Chemistry, University of Girona, Girona (Spain); Streli, Christina [TU Wien, Atominstitut,Radiation Physics, Vienna (Austria); Pepponi, Giancarlo [Fondazione Bruno Kessler, Povo, Trento (Italy); Stosnach, Hagen [Bruker Nano GmbH, Berlin (Germany); Yamada, Takashi [Rigaku Corporation, Takatsuki, Osaka (Japan); Vandenabeele, Peter [Department of Archaeology, Ghent University, Ghent (Belgium); Maina, David M.; Gatari, Michael [Institute of Nuclear Science and Technology, University of Nairobi, Nairobi (Kenya); Shepherd, Keith D.; Towett, Erick K. [World Agroforestry Centre (ICRAF), Nairobi (Kenya); Bennun, Leonardo [Laboratorio de Física Aplicada, Departamento de Física, Universidad de Concepción (Chile); Custo, Graciela; Vasquez, Cristina [Gerencia Química, Laboratorio B025, Centro Atómico Constituyentes, San Martín (Argentina); Depero, Laura E., E-mail: laura.depero@unibs.it [Chemistry for Technologies Laboratory, University of Brescia, Brescia (Italy)

    2014-11-01

    Total Reflection X-Ray Fluorescence (TXRF) is a mature technique to evaluate quantitatively the elemental composition of liquid samples deposited on clean and well polished reflectors. In this paper the results of the first worldwide TXRF round-robin test of water samples, involving 18 laboratories in 10 countries are presented and discussed. The test was performed within the framework of the VAMAS project, interlaboratory comparison of TXRF spectroscopy for environmental analysis, whose aim is to develop guidelines and a standard methodology for biological and environmental analysis by means of the TXRF analytical technique. - Highlights: • The discussion of the first worldwide TXRF round-robin test of water samples (18 laboratories of 10 countries) is reported. • Drinking, waste, and desalinated water samples were tested. • Data dispersion sources were identified: sample concentration, preparation, fitting procedure, and quantification. • The protocol for TXRF analysis of drinking water is proposed.

  10. Recent trends in total reflection X-ray fluorescence spectrometry for biological applications

    International Nuclear Information System (INIS)

    This review is focused on the application of total reflection X-ray fluorescence (TXRF) spectrometry in the field of biological research. In the last decade, most papers were published by authors who applied laboratory-scale TXRF equipments. The application of synchrotron radiation as excitation source (SR-TXRF) shows a slowly increasing tendency. In the cited papers the micro-, trace and multielement capability of these TXRF techniques was demonstrated in the clinical and medical laboratory practice, as well as in various plant physiological studies. For speciation of elements in biological matrices, the TXRF was used as element specific detector following an off-line separation step (e.g., thin layer chromatography, high performance liquid chromatography), however, these off-line methods are not competitive with the on-line coupled HPLC-inductively coupled plasma mass spectrometry

  11. Calibration method for measurement of linear nanometric distances by scattered total internal reflection

    International Nuclear Information System (INIS)

    Scattered total internal reflection of visible light is used to measure linear nanometric distance to as small as 10 nm. Specifically, we measure the height of magnetic transducer heads above a rotating glass disk. A breakthrough in the approach to calibration, based on combining the second derivative of the transmittance of the scattered light and parameter fitting, substantially improves the quality of the measurement relative to previous demonstrations of this method. The results agree to 1 nm with an industry-standard three-color interferometer to and including the lowest values measured. The technique in principle remains robust to as low as the zero height. Furthermore the calibration point can be as low as 10 nm, which is especially attractive in practice

  12. Evaluation of lateral resolution of scanning surface microscopy by total internal reflection with thermal lens effect.

    Science.gov (United States)

    Shimosaka, Takuya; Izako, Masakazu; Uchiyama, Katsumi; Hobo, Toshiyuki

    2003-06-01

    We have developed a novel method for in situ and non-destructive surface analyses, or a total internal reflection with thermal lens spectroscopy (TIR-TLS), which has sufficient sensitivity to monitor phenomena in thin films, such as lipid bilayers. In this study, we applied TIR-TLS to microscopy for surface analyses, and we experimentally obtained its lateral resolution using the edge of a chromium film made by a photolithography technique. The obtained resolution was 20 microm, which was 60% of the diameter of an excitation beam at the interface. The estimated resolution with a simple model agreed with the experimental one, and from this model, TIR-TLS microscopy has the same resolution as that of ordinary optical microscopy. The microscopy by TIR-TLS was applied to a sample whose contrast was too weak to be visually seen, and an image of the sample was obtained without any loss of resolution.

  13. Characterization of nuclear materials by total reflection X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Nuclear energy is one of the available energy options for long term energy security of world. In order to produce electricity using this mode of energy generation in an efficient and safe manner, it is necessary that the materials used for such energy generation comply with the specifications assigned. The major and trace composition of these materials is an important specification for their quality control. Different analytical techniques are used for such quality control. Total reflection X-ray fluorescence (TXRF) is a comparatively new technique having several features well suited for trace and major element determinations in nuclear materials. However, this technique has not been used so far extensively for characterization of nuclear materials. The present paper gives a brief introduction of TXRF, its suitability for nuclear material characterization and some details of the TXRF studies made in our laboratory for the characterization of nuclear materials. (author)

  14. Observation of high heat flux boiling structures in a horizontal pool by a total reflection technique

    International Nuclear Information System (INIS)

    The experiments were carried out for a horizontal pool boiling of saturated water using a transparent ITO heating surface. Details of boiling structure near the heated surface have been clearly observed by applying the total reflection and diagonal view techniques in a synchronized manner. Mechanisms for the bubble coalescence and dry area expansion processes were clearly identified. The base of the large massive bubble was mostly dry with some trapped liquid. The appearance of this large dry area at high heat flux close to CHF was basically resulted from the multiple steps of bubble coalescences which occur while the bubbles are growing, attached to the boiling surface not before they depart from the boiling surface. The thin liquid layer with distributed vapor stems was not observed under the large massive bubble. (author)

  15. Beer analysis by synchrotron radiation total reflection X-ray fluorescence (SR-TXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Dept. de Recursos Hidricos]. E-mail: silvana@fec.unicamp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br; Zucchi, Orgheda L.D.A. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas de Ribeirao Preto]. E-mail: olzucchi@fcfrp.usp.br

    2005-07-01

    In this work the concentrations of P, S, Cl, K, Ca, Mn, Fe, Zn and Br in twenty-nine brands of national and international beers were determined by Synchrotron Radiation Total Reflection X-Ray Fluorescence analysis (SR-TXRF). The results were compared with the limits established by the Brazilian Legislation and the nutritive values established by National Agricultural Library (NAL). The measurements were performed at the X-ray Fluorescence Beamline at Synchrotron Light Source Laboratory, in Campinas, Sao Paulo, Brazil, using a polychromatic beam for excitation. A small volume of 5 {mu}L of sample beers containing just an internal standard, used to correct geometry effects, were analyzed without any pre-treatment. The measuring time was 100 s and the detection limits obtained varied from 1{mu}g.L{sup -1} for Mn and Fe to 15{mu}g.L{sup -1} for P. (author)

  16. Metals determination in coffee sample by total reflection X-ray fluorescence analysis (TXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Vives, Ana Elisa Sirito de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Brienza, Sandra Maria Boscolo [ Universidade Metodista de Piracicaba (UNIMEP), Piracicaba, SP (Brazil). Faculdade de Ciencias Matematicas, da Natureza e de Tecnologia da Informacao]. E-mail: sbrienza@unimep.br; Zucchi, Orgheda Luiza Araujo Domingues [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio Franco do [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: virgilio@cena.usp.br

    2005-07-01

    The objective of this study was to evaluate the inorganic concentration in five brands of coffee, three of them nationally marketed and the others of an exportation kind. The samples were prepared by infusion with deionized water. To carry out the calibration, standard solutions were prepared with different concentrations of Al, Si, K, Ca, Ti, Cr, Fe, Ni, Zn and Se. The measurements were carried out using a white beam of synchrotron radiation for excitation and a Si (Li) semiconductor detector for detection. By employing Synchrotron Radiation Total Reflection X-Ray Fluorescence Analysis (SR-TXRF) it was possible to evaluate the concentrations of P, S, Cl, K, Ca, Mn, Fe, Cu, Zn, Rb and Ba. The detection limits for 300 s counting time were in the range of 0.03 (Ca) to 30 ng.g{sup -1} (Rb), respectively. (author)

  17. Ambiental applications of Total Reflection X-Ray Fluorescence in Mexico

    International Nuclear Information System (INIS)

    Full text: The National Institute of Nuclear Investigations, through the Management of Environmental Sciences has recently acquired a Total Reflection X Ray Fluorescence equipment, Ital Structures I T-2000. This is the first reflection equipment that operates in Mexico, and it allows to increase the analytic capacity in the environmental surface area of the country. This completely automated equipment is used in the environmental samples analysis, which means natural and wastewaters, silts and soils, blood, urine, fish, plankton, vegetables, filters with particulated matter, among other, using as quantification method the one called internal standard. The limits of detection vary from 4 up to 100 μg/L depending of the element and the used x-rays tube. This equipment allows to give support to different projects related with the contamination and the environmental protection in Mexico, just as the study of the distribution heavy metals in water and silt from different bodies of water, the metal accumulation in plankton, aquatic flowers, fish and birds, the study of particulate matter in Mexico City atmosphere, and in the identification of heavy metals in ground waters polluted with leached derived from mining industry

  18. Total reflection X-ray fluorescence and archaeometry: Application in the Argentinean cultural heritage

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, Cristina [Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Laboratorio de Quimica de Sistemas Heterogeneos, Facultad de Ingenieria, Universidad de Buenos Aires, P. Colon 850 (C1063ACU), Buenos Aires (Argentina)], E-mail: Cristina.Vazquez@cnea.gov.ar; Albornoz, Ana [Agencia Rio Negro Cultura, Museo de la Patagonia F.P.Moreno, Centro Civico s/n Bariloche, Rio Negro (Argentina); Hajduk, Adam [CONICET, Museo de la Patagonia F.P.Moreno, Centro Civico s/n Bariloche, Rio Negro (Argentina); Elkin, Dolores [CONICET Instituto Nacional de Antropologia y Pensamiento Latinoamericano, 3 de febrero 1378 (C1426AEL) Buenos Aires (Argentina); Custo, Graciela; Obrustky, Alba [Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina)

    2008-12-15

    Archaeometry is an interdisciplinary research area involved in the development and use of scientific methods in order to answer questions concerned with the human history. In this way the knowledge of archaeological objects through advanced chemical and physical analyses permits a better preservation and conservation of the cultural heritage and also reveals materials and technologies used in the past. In this sense, analytical techniques play an important role in order to provide chemical information about cultural objects. Considering the non destructive characteristic of this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Taking into account the irreplaceable character of the archaeological and artistic materials considered in this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Total Reflection X-ray Fluorescence Spectrometry as a geometric variant of conventional X-ray fluorescence is a proved microanalytical technique considering the small amount of sample required for the analysis. A few micrograms are enough in order to reveal valuable information about elemental composition and in this context it is highly recommended for artwork studies. In this paper a case study is presented in which Total Reflection X-Ray Fluorescence Spectrometry has been successfully employed in the archaeometry field. Examples from Argentinean cultural heritage sites related with the determination of pigments in paintings on canvas and in rock sites as well as in underwater archaeology research are shown.

  19. Total reflection X-ray fluorescence and archaeometry: Application in the Argentinean cultural heritage

    International Nuclear Information System (INIS)

    Archaeometry is an interdisciplinary research area involved in the development and use of scientific methods in order to answer questions concerned with the human history. In this way the knowledge of archaeological objects through advanced chemical and physical analyses permits a better preservation and conservation of the cultural heritage and also reveals materials and technologies used in the past. In this sense, analytical techniques play an important role in order to provide chemical information about cultural objects. Considering the non destructive characteristic of this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Taking into account the irreplaceable character of the archaeological and artistic materials considered in this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Total Reflection X-ray Fluorescence Spectrometry as a geometric variant of conventional X-ray fluorescence is a proved microanalytical technique considering the small amount of sample required for the analysis. A few micrograms are enough in order to reveal valuable information about elemental composition and in this context it is highly recommended for artwork studies. In this paper a case study is presented in which Total Reflection X-Ray Fluorescence Spectrometry has been successfully employed in the archaeometry field. Examples from Argentinean cultural heritage sites related with the determination of pigments in paintings on canvas and in rock sites as well as in underwater archaeology research are shown

  20. Analysis of total oil and fatty acids composition by near infrared reflectance spectroscopy in edible nuts

    Science.gov (United States)

    Kandala, Chari V.; Sundaram, Jaya

    2014-10-01

    Near Infrared (NIR) Reflectance spectroscopy has established itself as an important tool in quantifying water and oil present in various food materials. It is rapid and nondestructive, easier to use, and does not require processing the samples with corrosive chemicals that would render them non-edible. Earlier, the samples had to be ground into powder form before making any measurements. With the development of new soft ware packages, NIR techniques could now be used in the analysis of intact grain and nuts. While most of the commercial instruments presently available work well with small grain size materials such as wheat and corn, the method present here is suitable for large kernel size products such as shelled or in-shell peanuts. Absorbance spectra were collected from 400 nm to 2500 nm using a NIR instrument. Average values of total oil contents (TOC) of peanut samples were determined by standard extraction methods, and fatty acids were determined using gas chromatography. Partial least square (PLS) analysis was performed on the calibration set of absorption spectra, and models were developed for prediction of total oil and fatty acids. The best model was selected based on the coefficient of determination (R2), Standard error of prediction (SEP) and residual percent deviation (RPD) values. Peanut samples analyzed showed RPD values greater than 5.0 for both absorbance and reflectance models and thus could be used for quality control and analysis. Ability to rapidly and nondestructively measure the TOC, and analyze the fatty acid composition, will be immensely useful in peanut varietal improvement as well as in the grading process of grain and nuts.

  1. Total reflection x-ray fluorescence: Determination of an optimum geometry

    International Nuclear Information System (INIS)

    Total reflection X-Ray Fluorescence (TXRF) is a widely used technique in which the normal trace element detection capability of hard x-ray fluorescence (XRF) is enhanced by use of an x-ray reflective substrate. TXRF is more sensitive than normal photon induced XRF due to the reduction of the substrate scattering and fluorescence signals. This reduction comes about because in total external reflection, the photon field only penetrates about 20 angstrom into the surface, instead of typically 50 μm for a silicon substrate at normal incidence for 10 KeV photons. The technique is used in many fields of trace element analysis, and is widely used in the determination of metal impurity concentrations on and in the surface of silicon wafers. The Semiconductor Industry Association roadmap (SIA) indicates a need for wafer contamination detection at the 107atoms/cm2 level in the next few years. Current commercial systems using rotating anode x-ray sources presently routinely operate with a sensitivity level of around 1010 atoms/cm2 and this has led to interest in the use of synchrotron radiation to extend the sensitivity by three orders of magnitude. The pioneering work of Pianetta and co-workers at SSRL has clearly shown that this should be possible, using a fully optimized source and detector. The purpose of this work is to determine whether ALS would be a suitable source for this type of highly sensitive wafer TXRF. At first look it appears improbable as the SSRL work used a high flux multipole wiggler source, and it is clear that the detected fluorescence for relevant concentrations is small. In addition, SSRL operates at 3.0 GeV rather than 1.9 GeV, and is therefore more naturally suited to hard x-ray experiments. The aim of this work was therefore to establish a theoretical model for the scattering and fluorescence processes, so that one could predict the differences between alternative geometries and select an optimum configuration

  2. Collection of airborne particulate matter for a subsequent analysis by total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Klockenkaemper, R.; Bayer, H.; Bohlen, A. von; Schmeling, M.; Klockow, D. [Institut fuer Spektrochemie und Angewandte Spektroskopie, Dortmund (Germany)

    1995-06-01

    The collection of airborne particulate matter by filtration and impaction was adapted to total reflection X-ray fluorescence analysis (TXRF). Cellulose nitrate filters were used for collecting in a Berner impactor. Single filter spots were punched out, placed on quartz-glass carriers, dissolved by tetrahydrofuran and re-precipitated prior to element determinations by TXRF. In a Battelle-type impactor, airborne dust was collected on Plexiglass carriers coated with medical Vaseline. The loaded carriers were directly analyzed by TXRF. In both cases, quantification was simply performed by the addition of an internal standard after sampling. Impactors were made of a suitable material in order to investigate high blank values, collection losses and memory effects. It could be shown that stainless steel, even coated with TiN, is less suitable and should be avoided as an impactor material. Although aluminum is partly recommendable, titanium and the polymer Makrolon are quite appropriate. By using an impactor made of these materials, a reliable multielement determination in airborne dust is made possible with low detection limits as low as 1 ng/m{sup 3} and a satisfactory repeatability of a few %. Short sampling times of only 1 h or less can be realized. The total procedure is simple and time-saving, and can be recommended for routine investigations of airborne particulate matter. (author).

  3. High nitrate to phosphorus regime attenuates negative effects of rising pCO2 on total population carbon accumulation

    Science.gov (United States)

    Matthiessen, B.; Eggers, S. L.; Krug, S. A.

    2012-03-01

    The ongoing rise in atmospheric pCO2 and consequent increase in ocean acidification have direct effects on marine calcifying phytoplankton, which potentially alters carbon export. To date it remains unclear, firstly, how nutrient regime, in particular by coccolithophores preferred phosphate limitation, interacts with pCO2 on particulate carbon accumulation; secondly, how direct physiological responses on the cellular level translate into total population response. In this study, cultures of Emiliania huxleyi were full-factorially exposed to two different N:P regimes and three different pCO2 levels. Cellular biovolume and PIC and POC content significantly declined in response to pCO2 in both nutrient regimes. Cellular PON content significantly increased in the Redfield treatment and decreased in the high N:P regime. Cell abundance significantly declined in the Redfield and remained constant in the high N:P regime. We hypothesise that in the high N:P regime severe phosphorous limitation could be compensated either by reduced inorganic phosphorous demand and/or by enzymatic uptake of organic phosphorous. In the Redfield regime we suggest that enzymatic phosphorous uptake to supplement enhanced phosphorous demand with pCO2 was not possible and thus cell abundance declined. These hypothesised different physiological responses of E. huxleyi among the nutrient regimes significantly altered population carrying capacities along the pCO2 gradient. This ultimately led to the attenuated total population response in POC and PIC content and biovolume to increased pCO2 in the high N:P regime. Our results point to the fact that the physiological (i.e. cellular) PIC and POC response to ocean acidification cannot be linearly extrapolated to total population response and thus carbon export. It is therefore necessary to consider both effects of nutrient limitation on cell physiology and their consequences for population size when predicting the influence of coccolithophores on

  4. Novel Propagation Properties of Total Internal Reflection Photonic Crystal Fibres with Rhombic Air Holes

    Institute of Scientific and Technical Information of China (English)

    YAN Hai-Feng; YU Zhong-Yuan; LIU Yu-Min; TIAN Hong-Da; HAN Li-Hong

    2011-01-01

    We investigate the propagation properties of a multi-layer photonic crystal fiber with novel rhombic air holes using the finite element method,and calculate the dependence of the propagation properties on the wavelength in the fiber with different geometrical structural parameters,including the internal angle and the external arrangement of the rhombic air holes.Optimizing these parameters,we design a photonic crystal which exhibits both a small dispersion value and low loss near the wavelength of 1.55 μm.Photonic crystal fibers are known as microstructured optical fibers or multi-hole optical fibers,and their cross sections have periodic structures with hollows in the centers due to one or more missing air holes as shown in Fig.1.The light wave can propagate along this hollow structure,which can be considered as the core of the fiber.According to the light-guiding mechanism,there are two types of photonic crystal fibers:total internal reflection photonic crystal fibers and photonic bandgap photonic crystal fibers.[1] The propagation properties of total internal reflection photonic crystal fibers are determined by the arrangements of holes in the transverse field.[1,2] With the flexibility to control the arrangement,size and shape of the air holes,various photonic crystal fibers with different optical properties can be designed as desired.Recently the microstructural design of photonic crystal fibers has drawn extensive attention over the world.[3] As a novel kind of optical fiber,photonic crystal fibers have been widely used for optoelectronic devices.%We investigate the propagation properties of a multi-layer photonic crystal fiber with novel rhombic air holes using the finite element method, and calculate the dependence of the propagation properties on the wavelength in the fiber with different geometrical structural parameters, including the internal angle and the external arrangement of the rhombic air holes. Optimizing these parameters, we design a photonic

  5. Thermal dissociation cavity attenuated phase shift spectroscopy for continuous measurement of total peroxy and organic nitrates in the clean atmosphere

    Science.gov (United States)

    Sadanaga, Yasuhiro; Takaji, Ryo; Ishiyama, Ayana; Nakajima, Kazuo; Matsuki, Atsushi; Bandow, Hiroshi

    2016-07-01

    A thermal dissociation cavity attenuated phase shift spectroscopy (TD-CAPS) instrument was developed for measuring total peroxy nitrates (PNs) and organic nitrates (ONs) concentrations in the clean atmosphere. This instrument is easy to operate and can be applied to continuous measurement of PNs and ONs. A continuously measurable system is convenient to perform observations, especially in remote areas. Three lines (NO2, PNs, and ONs lines) were used for thermal dissociation. The NO2 line contains a quartz tube that is not heated, while the PN and ON lines contain quartz tubes that are heated at 433 K and 633 K, respectively. The concentrations of NO2, NO2 + PNs, and NO2 + PNs + ONs can be obtained from the NO2, PN, and ON lines, respectively. The lower limit values of the detection limit (3σ) for PNs and ONs were estimated to be 21 parts per trillion by volume with an integration time of 2 min. PNs were selectively thermally decomposed in the PNs line and formed NO2 quantitatively. In the ONs line, both PNs and ONs were thermally decomposed to produce NO2 quantitatively, but partial decomposition of HNO3 at 633 K interfered with the ONs measurement. Therefore, a HNO3 scrubber is required before the ONs line. Continuous observations were conducted with the TD-CAPS instrument in a remote area, and the instrument performed well for obtaining PNs and ONs concentrations.

  6. Radio-frequency Attenuation Length, Basal-Reflectivity, Depth, and Polarization Measurements from Moore's Bay in the Ross Ice-Shelf

    CERN Document Server

    Barwick, S W; Besson, D; Duffin, T; Hanson, J C; Klein, S R; Kleinfelder, S A; Reed, C; Roumi, M; Stezelberger, T; Tatar, J; Walker, J; Zou, L

    2014-01-01

    Radio-glaciological parameters from Moore's Bay, in the Ross Ice Shelf, have been measured. The thickness of the ice shelf in Moore's Bay was measured from reflection times of radio-frequency pulses propagating vertically through the shelf and reflecting from the ocean. The average depth obtained is $576\\pm8$ m. The temperature-averaged attenuation length of the ice column, $\\langle L \\rangle$, is derived from the returned power assuming 100\\% reflection. A linear fit to the data yields $\\langle L(\

  7. Portable total reflection x-ray fluorescence spectrometer for ultra trace elemental determination

    International Nuclear Information System (INIS)

    It has been believed that the use of high power monochromatic incident X-rays such as monochromatic synchrotron radiation is essential for improving detection limits in the total reflection X-ray fluorescence (TXRF) analysis. On the other hand, we have reported that polychromatic excitation improves detection limits in the TXRF analysis compared with monochromatic excitation. We have developed portable TXRF spectrometers using polychromatic X-rays from a low power (several watts) X-ray tube, and a 10 pg (10-11 g) detection limit is achieved with the weak polychromatic X-rays. This low detection limit is obtained using the following methods with polychromatic excitation: (1) measuring smaller amounts of a sample, (2) optimization of a tube voltage, and tube current, (3) optimization of a glancing angle, (4) the use of an appropriate target material of an X-ray tube, and (5) the use of an X-ray waveguide. In the present paper, experimental set-up of the present portable spectrometer and the change of detection sensitivity by changing experimental conditions such as tube voltage are explained. Applications to trace elemental analysis of urine and pigments are also shown. (author)

  8. Analysis of mineral water from Brazil using total reflection X-ray fluorescence by synchrotron radiation

    International Nuclear Information System (INIS)

    The total reflection X-ray fluorescence using synchrotron radiation (SRTXRF) has become a competitive technique for the determination of trace elements in samples that the concentrations are lower than 100 ng ml-1. In this work, thirty-seven mineral waters commonly available in supermarkets of Rio de Janeiro, Brazil, were analyzed by SRTXRF. The measurements were performed at the X-Ray Fluorescence Beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo, using a polychromatic beam with maximum energy of 20 keV for the excitation. Standard solutions with gallium as internal standard were prepared for calibration of the system. Mineral water samples of 10 μl were added to Perspex sample carrier, dried under infrared lamp and analyzed for 200 s measuring time. It was possible to determine the concentrations of the following elements: Si, S, K, Ca, Ti, Cr, Mn, Ni, Cu, Zn, Ge, Rb, Sr, Ba and Pb. The elemental concentration values were compared with the limits established by the Brazilian legislation

  9. Frustrated total internal reflection in organic light-emitting diodes employing sphere cavity embedded in polystyrene

    Science.gov (United States)

    Zhu, Peifen

    2016-02-01

    The light extraction efficiency of top-emitting organic light-emitting diodes (OLEDs) is numerically investigated employing the finite-difference time-domain method. The periodic nanostructures formed by embedding the sphere arrays in polystyrene (PS) are placed on top of OLED to frustrate the total internal reflection at the interface between OLED and free space. These nanostructures serve as an intermediate medium to extract the light out of OLED devices. Efficiently coupling both evanescent waves and propagation waves into spheres and subsequently extracting these light waves out of the sphere is key to achieving high extraction efficiency. By tuning the thickness of PS layer, both of the in-coupling efficiency and out-coupling efficiency are optimized for achieving high light extraction efficiency. Thicker PS layer results in higher in-coupling efficiency in sphere while the thinner PS layer leads to higher out-coupling efficiency. Thus the maximum light extraction is a trade-off between the in-coupling efficiency and out-coupling efficiency. The study shows that light extraction efficiency of 89% can be achieved by embedding 0.90 μm TiO2 sphere in 0.30 μm PS layer with optimized in-coupling efficiency, out-coupling efficiency and cavity effect.

  10. Characterization and classification of spirituous beverages by total reflection x-ray fluorescence

    International Nuclear Information System (INIS)

    The total reflection x-ray fluorescence (TXRF) technique was applied for the multi-elemental analysis of spirituous beverages like rum, cocuy (typical spirituous beverage in Venezuela), whiskey and wine, in order to classify the samples by product processing and geographical origin by chemometric analysis. Special attention was paid to the cocuy samples, since there is a lack of quality control of this beverage, mainly due to the home-made product processing. The use of the Compton peak information was evaluated for the determination of organic content in samples. In the specifically case of cocuy samples the Compton peak area was correlated to the ash content for detection of adulteration with sugar syrup. Cocuy samples were also analyzed using gas chromatography, for pH, acidity, ash content and refractometry, in order to develop the recognition pattern. The TXRF analysis was carried out in a Canberra spectrometer, using the K α-line of a Motube, by a direct procedure previously developed. The analysis of the data was done by using principal components analysis and a confidence test. The results show that TXRF and chemometric analysis is a useful tool for quality control of spirituous beverages, not only concerning to metal content, but also in the evaluation of sugar and non volatile organic content. (author)

  11. Near-wall nanovelocimetry based on Total Internal Reflection Fluorescence with continuous tracking

    CERN Document Server

    Li, Zhenzhen; Lee, Choongyeop; Monti, Fabrice; Yonger, Marc; Chollet, Benjamin; Bresson, Bruno; Tran, Yvette; Tabeling, Patrick

    2014-01-01

    The goal of this work is to make progress in the domain of near-wall velocimetry. The technique we use is based on the tracking of nanoparticles in an evanescent field, close to a wall, a technique called TIRF (Total Internal Reflection Fluorescence)-based velocimetry. At variance with the methods developed in the literature, we permanently keep track of the light emitted by each particle during the time the measurements of their positions ('altitudes') and speeds are performed. By performing the Langevin simulation, we quantified effect of biases such as Brownian motion, heterogeneities induced by the walls, statistical biases, photo bleaching, polydispersivity and limited depth of field. Using this method, we obtained slip length on hydrophilic surfaces of 1$ \\pm $5 nm for sucrose solution, and 9$ \\pm $10 nm for water; On hydrophobic surface, 32$ \\pm $5 nm for sucrose solution, and 55$ \\pm $9 nm for water. The errors (based on 95% confidence intervals) are significantly smaller than the state-of-the-art, bu...

  12. Use of liposomal amplifiers in total internal reflection fluorescence fiber-optic biosensors for protein detection.

    Science.gov (United States)

    Chang, Ying-Feng; Fu, Chen; Chen, Yi-Ting; Fang-Ju Jou, Amily; Chen, Chii-Chang; Chou, Chien; Annie Ho, Ja-An

    2016-03-15

    Evanescent-wave excited fluorescence technology has been demonstrated to enhance sensitivity and reduce matrix effects, making it suitable for biosensor development. In this study, we developed a liposome-based, total internal reflection fluorescence, fiber-optic biosensor (TIRF-FOB) for protein detection, which integrates a liposomal amplifier and sandwich immunoassay format with TIRF-FOB. In addition, the antibody-tagged and fluorophore-entrapped liposomes for heterogeneous detection of target molecules were designed and synthesized. This biosensor successfully detected the target protein (model analyzed here is IgG) with a limit of detection (LOD) of 2.0 attomoles for the target protein (equivalent to 2.0 pg/mL of protein presented in 150 μL of sample solution). The features of this ultra-sensitive liposomal TIRF-FOB are (i) fluorescence is excited via evanescent waves and amplified via liposomes; (ii) the use of two polyclonal antibodies in the sandwich assay format increases the specificity and lowers the cost of our assay. Based on the exceptional detection sensitivity and cost-effectiveness, we believe that the proposed biosensor has great potential as a practical, clinical diagnostic tool in the near future. PMID:26595485

  13. Angle-invariant imaging using a total internal reflection virtual aperture.

    Science.gov (United States)

    Agurok, Ilya P; Ford, Joseph E

    2016-07-10

    Conventional lens stops, implemented with an absorptive physical aperture, have an angle-dependent projection that introduces field dependent loss and reduces diffraction-limited resolution. Retro-telephoto lenses obtain uniform response using aberration vignetting, but this results in low wide-angle resolution and significant lens volume. However, an angle-independent "virtual" aperture can be created by total internal reflection (TIR) from a thin low index layer inside the lens. We apply this to monocentric wide-angle imaging and find a simple relationship between the filtering layer index and radius and the resulting lens F/#. We provide two detailed designs of lenses with 12 mm focal length and a F/2.5 TIR stop, one using a low index adhesive within a solid fixed-focus lens, the other using an air cavity within an adjustable focus lens. We show the designs provide absolutely uniform resolution and light collection over an angle range of 84° and 106°, respectively, resulting in a dramatic improvement of both light collection and angular resolution per unit volume over conventional wide-angle lenses. PMID:27409309

  14. Sample pretreatment strategies for total reflection X-ray fluorescence analysis: A tutorial review

    Energy Technology Data Exchange (ETDEWEB)

    De La Calle, I.; Cabaleiro, N.; Romero, V.; Lavilla, I.; Bendicho, C., E-mail: bendicho@uvigo.es

    2013-12-01

    In the last years, there has been a revival of total reflection X-ray fluorescence spectrometry (TXRF), which was firstly applied for analytical purposes in the late 80s. The aim of this work is to discuss and compare the current approaches for sample pretreatment including in situ microdigestion, slurry preparation, acid digestion, extraction, etc. prior to TXRF analysis. Advantages and drawbacks inherent to each of those procedures are considered. A comprehensive revision in the period January 2008–July 2013 about different sample preparation strategies prior to TXRF analysis apart from early pioneering reports dealing with sample pretreatment are included in the review. Non-conventional sample pretreatment approaches such as microflow online preconcentration, lab-on-a-chip, etc., are also discussed. Finally, future prospects in sample preparation prior to TXRF analysis are outlined. - Highlights: • We review sample pretreatment for TXRF in a comprehensive way. • Strategies for analysis of solid, liquid and gaseous samples are discussed. • A tutorial review is presented covering the period January 2008–July 2013. • Future prospects for sample pretreament approaches in TXRF are outlined.

  15. Preparation of Reactions for Imaging with Total Internal Reflection Fluorescence Microscopy.

    Science.gov (United States)

    Kudalkar, Emily M; Davis, Trisha N; Asbury, Charles L

    2016-01-01

    Here we present our standard protocol for studying the binding of kinetochore proteins to microtubules as a paradigm for designing single-molecule total internal reflection fluorescence (TIRF) microscopy experiments. Several aspects of this protocol require empirical optimization, including the method for anchoring the polymer or substrate to the coverslip, the type and amount of blocking protein to prevent nonspecific protein adsorption to the glass, the appropriate protein concentration, the laser power, and the duration of imaging. Our method uses bovine serum albumin and κ-casein as blocking agents to coat any imperfections in the coverslip silanization and thereby prevent protein adsorption to the coverslip. Protein concentration and duration of imaging must be optimized for each experiment and protein of interest. Ideally, a range is determined that allows for resolution of single complexes binding to microtubules to ensure proper measurement of kinetic off rates and diffusion along microtubules. Excessively high concentrations may lead to overlapping binding of proteins on microtubules, making it impossible to resolve single binding events. The duration of imaging must be long enough to capture very low off rates (long residence time on microtubules) and we typically image at 10 frames/sec for 200 sec. The laser power can be adjusted to prevent photobleaching, but must be high enough to achieve a sufficient signal/noise ratio. PMID:27140912

  16. Development of a total reflection X-ray fluorescence spectrometer for ultra-trace element analysis

    Indian Academy of Sciences (India)

    M K Tiwari; B Gowrishankar; V K Raghuvanshi; R V Nandedkar; K J S Sawhney

    2002-10-01

    A simple and fairly inexpensive total reflection X-ray fluorescence (TXRF) spectrometer has been designed, constructed and realized. The spectrometer is capable of ultra-trace multielement analysis as well as performs surface characterization of thin films. The TXRF setup comprises of an X-ray generator, a slitcollimator arrangement, a monochromator/cutoff-stage, a sample reflector stage and an X-ray detection system. The glancing angle of incidence on the two reflectors is implemented using a sine-bar mechanism that enables precise angle adjustments. An energy dispersive detector and a GM counter are employed for measuring respectively the fluorescence intensities and the direct X-ray beam intensity. A Cu-target X-ray generator with its line focus window is used as an excitation source. The spectrometer is quite portable with its compact design and use of a peltier cooled solid state detector for energy dispersive detection. Alignment and characterization of the TXRF system has been performed and the minimum detection limits for various elements have been determined to be in the range of 100 pg to 5 ng even at low X-ray generator powers of 30 kV, 5 mA. The capability of the TXRF system developed for thin film characterization is also demonstrated.

  17. Total Reflection X-ray Fluorescence Analysis (TXRF) using the high flux SAXS camera

    CERN Document Server

    Wobrauschek, P; Pepponi, G; Bergmann, A; Glatter, O

    2002-01-01

    Combining the high photon flux from a rotating anode X-ray tube with an X-ray optical component to focus and monochromatize the X-ray beam is the most promising instrumentation for best detection limits in the modern XRF laboratory. This is realized by using the design of a high flux SAXS camera in combination with a 4 kW high brilliant rotating Cu anode X-ray tube with a graded elliptically bent multilayer and including a new designed module for excitation in total reflection geometry within the beam path. The system can be evacuated thus reducing absorption and scattering of air and removing the argon peak in the spectra. Another novelty is the use of a Peltier cooled drift detector with an energy resolution of 148 eV at 5.9 keV and 5 mm sup 2 area. For Co detection limits of about 300 fg determined by a single element standard have been achieved. Testing a real sample NIST 1643d led to detection limits in the range of 300 ng/l for the medium Z.

  18. Multielemental analysis in cigarettes using total reflection X-ray fluorescence with synchrotron radiation

    International Nuclear Information System (INIS)

    Full text: It is well known that trace elements have important ejects in the life processes. Some of these elements are toxic for the human even at a very low level of intake. It is known that tobacco plant easily absorbs the heavy metals from the soil, especially Cd and Ni, accumulating them in its leaves. Part of these metals are transferred from tobacco to human body where they will be accumulated and damage some organs, mainly kidneys and liver. In this way, cigarettes are responsible for the death of millions of people in the world, about one death every eight seconds. The aim of this work was to determine the elemental concentrations of ten different elements in tobacco of Brazilian cigarettes used Total Reflection X-Ray Fluorescence with Synchrotron Radiation method. The fluorescence measurements were carried out at Brazilian Synchrotron Light Laboratory, Campinas - Sao Paulo. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, chromium, manganese, iron, copper, rubidium and strontium. Among these elements, calcium, potassium and iron presented the highest concentrations. There was a wide range in the elemental concentrations in the tobacco, due various factors, such as agricultural practices, soil characteristics, climatic conditions and plant varieties. Our results are in good concern with the results reported by the scientific literature

  19. Total reflection X-ray fluorescence as a tool for food screening

    Science.gov (United States)

    Borgese, Laura; Bilo, Fabjola; Dalipi, Rogerta; Bontempi, Elza; Depero, Laura E.

    2015-11-01

    This review provides a comprehensive overview of the applications of total reflection X-ray fluorescence (TXRF) in the field of food analysis. Elemental composition of food is of great importance, since food is the main source of essential, major and trace elements for animals and humans. Some potentially toxic elements, dangerous for human health may contaminate food, entering the food chain from the environment, processing, and storage. For this reason the elemental analysis of food is fundamental for safety assessment. Fast and sensitive analytical techniques, able to detect major and trace elements, are required as a result of the increasing demand on multi-elemental information and product screening. TXRF is suitable for elemental analysis of food, since it provides simultaneous multi-elemental identification in a wide dynamic range of concentrations. Several different matrices may be analyzed obtaining results with a good precision and accuracy. In this review, the most recent literature about the use of TXRF for the analysis of food is reported. The focus is placed on the applications within food quality monitoring of drinks, beverages, vegetables, fruits, cereals, animal derivatives and dietary supplements. Furthermore, this paper provides a critical outlook on the developments required to transfer these methods from research to the industrial and analytical laboratories contexts.

  20. Elemental concentration analysis in prostate tissues using total reflection X-ray fluorescence

    Science.gov (United States)

    Leitão, R. G.; Palumbo, A.; Souza, P. A. V. R.; Pereira, G. R.; Canellas, C. G. L.; Anjos, M. J.; Nasciutti, L. E.; Lopes, R. T.

    2014-02-01

    Prostate cancer (PCa) currently represents the second most prevalent malignant neoplasia in men, representing 21% of all cancer cases. Benign Prostate Hyperplasia (BPH) is an illness prevailing in men above the age of 50, close to 90% after the age of 80. The prostate presents a high zinc concentration, about 10-fold higher than any other body tissue. In this work, samples of human prostate tissues with cancer, BPH and normal tissue were analyzed utilizing total reflection X-ray fluorescence spectroscopy using synchrotron radiation technique (SR-TXRF) to investigate the differences in the elemental concentrations in these tissues. SR-TXRF analyses were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, São Paulo. It was possible to determine the concentrations of the following elements: P, S, K, Ca, Fe, Cu, Zn and Rb. By using Mann-Whitney U test it was observed that almost all elements presented concentrations with significant differences (α=0.05) between the groups studied.

  1. Investigation of polyelectrolytes by total reflection x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Water soluble polyelectrolyte samples containing mono-, bi- and trivalent metal ions were investigated without any pretreatment. Acid digestion of linear polymers may lead to a product insoluble in water so the digestion has to be avoided. The aim of this paper was the determination of analytical characteristics and limitations of the total reflection x-ray fluorescence (TXRF) analysis for poly (vinylalcohol-vinylsulphate) salts and poly (acrylic acid, acrylamide) copolymers containing the following cations: K+, Cs+, Ba2+, Cu2+ and La3+. On the basis of our results efficiency of ion-exchange during preparation of polyelectrolytes and stoichiometry of the end-product were determined. TXRF results were compared with data gained by inductively coupled plasma atomic emission spectrometry (ICP-AES) measurements except in the case of Cs+ which has poor sensitivity in ICP-AES. Good agreement was found between the results of the two techniques and calculations from titrimetric data. Concentration of Li+ and Mg2+ in polymer samples was measured by ICP-AES. In majority of cases film-like dry residues of aqueous solutions of polyelectrolytes can be characterized by homogeneous spatial distribution of metal ions within the organic matrix. This is because the migration of the ions is hindered during drying process. Determination of metals in polyelectrolyte films by TXRF is quite ideal as model for analysis of plant, animal or human tissues which is a frequent task in environmental and inorganic biomedical analytical chemistry. (author)

  2. Novel Bio, Chemical, Environmental Sensing Based on New Model of Total Internal Reflection in Turbid Media

    Science.gov (United States)

    Bali, Samir; Judge, Patrick; Phillip, Nathan; Boivin, Jordan; Scaffidi, Jonathan; Berberich, Jason; Bali, Lalit

    2014-05-01

    We have initiated a collaborative experimental research program that combines new advances in optical physics, field portable chemical analysis, and biosensing. Our goal is to discover and characterize new optical sensing methodologies in opaque, highly scattering (i.e., ``turbid'') media, and demonstrate new paradigms for optical sensing in research and industry. We have three specific objectives. First, we propose to fully characterize and validate a new model of total internal reflection (TIR) from highly turbid media thus enabling a first demonstration of non-invasive, in-situ, real-time particle sizing for the case of arbitrary scattering particle size-a holy grail in colloidal science. Second, we propose to implement a first demonstration of real-time non-invasive measurement of nanoparticle aggregation in highly turbid media. Third, we propose to use our new sensing methodology to demonstrate real-time in-situ label-free monitoring of molecular interactions and adsorption at surfaces. We gratefully acknowledge support from the American Chemical Society Petroleum Research Fund and Miami University's Interdisciplinary Roundtable Fund. We also gratefully acknowledge experimental help from the Miami University Instrumentation Laboratory.

  3. Total reflection X-ray fluorescence analysis of pollen as an indicator for atmospheric pollution*1

    Science.gov (United States)

    Pepponi, G.; Lazzeri, P.; Coghe, N.; Bersani, M.; Gottardini, E.; Cristofolini, F.; Clauser, G.; Torboli, A.

    2004-08-01

    The viability of pollen is affected by environmental pollution and its use as a bio-indicator is proposed. Such effects can be observed and quantified by biological tests. However, a more accurate identification of the agents affecting the viability is required in order to validate the biological assay for environmental monitoring. The chemical analysis of pollen is meant to ascertain the existence of a correlation between its reduced biological functions and the presence of pollutants. Moreover, such biological systems act as accumulators and allow the detection and quantification of species present in the environment at low concentrations. Total reflection X-ray fluorescence analysis (TXRF) has been chosen for the investigation due to its high sensitivity, multielement capability and wide dynamic range. Corylus avellana L. (hazel) pollen has been collected in areas with different anthropic impact in the province of Trento, Italy. For the TXRF measurements, a liquid sample is needed, especially if a quantitative analysis is required. In the present work, the analysis after a microwave digestion has been compared with the analysis of a suspension of the pollen samples. In both cases, an internal standard has been used for the quantification. The concentrations of 17 elements ranging from Al to Pb have been determined in 13 samples. Analysis of the suspensions showed to be comparable to that of digested samples in terms of spectral quality, but the latter preparation method gave better reproducibility. Sub-ppm lowest limits of detection were obtained for iron and heavier elements detected.

  4. High nitrate to phosphorus regime attenuates negative effects of rising pCO2 on total population carbon accumulation

    Directory of Open Access Journals (Sweden)

    S. A. Krug

    2012-03-01

    Full Text Available The ongoing rise in atmospheric pCO2 and consequent increase in ocean acidification have direct effects on marine calcifying phytoplankton, which potentially alters carbon export. To date it remains unclear, firstly, how nutrient regime, in particular by coccolithophores preferred phosphate limitation, interacts with pCO2 on particulate carbon accumulation; secondly, how direct physiological responses on the cellular level translate into total population response. In this study, cultures of Emiliania huxleyi were full-factorially exposed to two different N:P regimes and three different pCO2 levels. Cellular biovolume and PIC and POC content significantly declined in response to pCO2 in both nutrient regimes. Cellular PON content significantly increased in the Redfield treatment and decreased in the high N:P regime. Cell abundance significantly declined in the Redfield and remained constant in the high N:P regime. We hypothesise that in the high N:P regime severe phosphorous limitation could be compensated either by reduced inorganic phosphorous demand and/or by enzymatic uptake of organic phosphorous. In the Redfield regime we suggest that enzymatic phosphorous uptake to supplement enhanced phosphorous demand with pCO2 was not possible and thus cell abundance declined. These hypothesised different physiological responses of E. huxleyi among the nutrient regimes significantly altered population carrying capacities along the pCO2 gradient. This ultimately led to the attenuated total population response in POC and PIC content and biovolume to increased pCO2 in the high N:P regime. Our results point to the fact that the physiological (i.e. cellular PIC and POC response to ocean acidification cannot be linearly extrapolated to total population response and thus carbon export. It is therefore necessary to consider both effects of nutrient limitation on cell physiology and their consequences for population size when predicting the influence of

  5. Adhesion of living cells revealed by variable-angle total internal reflection fluorescence microscopy (Conference Presentation)

    Science.gov (United States)

    Cardoso Dos Santos, Marcelina; Vézy, Cyrille; Jaffiol, Rodolphe

    2016-02-01

    Total Internal Reflection Fluorescence Microscopy (TIRFM) is a widespread technique to study cellular process occurring near the contact region with the glass substrate. In this field, determination of the accurate distance from the surface to the plasma membrane constitutes a crucial issue to investigate the physical basis of cellular adhesion process. However, quantitative interpretation of TIRF pictures regarding the distance z between a labeled membrane and the substrate is not trivial. Indeed, the contrast of TIRF images depends on several parameters more and less well known (local concentration of dyes, absorption cross section, angular emission pattern…). The strategy to get around this problem is to exploit a series of TIRF pictures recorded at different incident angles in evanescent regime. This technique called variable-angle TIRF microscopy (vaTIRFM), allowing to map the membrane-substrate separation distance with a nanometric resolution (10-20 nm). vaTIRFM was developed by Burmeister, Truskey and Reichert in the early 1990s with a prism-based TIRF setup [Journal of Microscopy 173, 39-51 (1994)]. We propose a more convenient prismless setup, which uses only a rotatable mirror to adjust precisely the laser beam on the back focal plane of the oil immersion objective (no azimuthal scanning is needed). The series of TIRF images permit us to calculate accurately membrane-surface distances in each pixel. We demonstrate that vaTIRFM are useful to quantify the adhesion of living cells for specific and unspecific membrane-surface interactions, achieved on various functionalized substrates with polymers (BSA, poly-L-lysin) or extracellular matrix proteins (collagen and fibronectin).

  6. Characterization of urban air pollution by total reflection X-ray fluorescence*1

    Science.gov (United States)

    Schmeling, Martina

    2004-08-01

    Besides photochemical smog, particulate air pollution is a constantly growing problem in urban areas. The particulate matter present in pollution events contains often toxic or health impacting elements and is responsible for low visibility, might be triggering respiratory diseases like asthma, and can play an important role in formation or duration of smog events. To characterize particulate pollution in two different cities, samples were taken during intensive field campaigns in Chicago, IL, in 2002 and Phoenix, AZ, in 2001. Both cities experience regularly photochemical smog events as well as particulate pollution, but show very different meteorological and topographical conditions. Therefore it is expected that the particulate composition varies significantly, providing information about different pollution forms. Sampling took place in both cases at elevated locations and had a temporal resolution of 1.5 h and 1 h, respectively. The samples were analyzed by total reflection X-ray fluorescence after digestion of the filter matrix. As expected the elemental composition of particulate matter varied between both cities substantially with Phoenix showing a higher abundance of crustal elements, and Chicago enrichment in anthropogenically produced ones. In both cities diurnal patterns were found, exerting maxima in the morning and minima in the early afternoon. The diurnal pattern was much more regularly and also more strongly pronounced in Phoenix. Phoenix's valley location permits for a more stable nocturnal boundary layer to build up during the night thus trapping particulates efficiently during this time, until mixing occurs in the early morning hours and the residual layer lifts. In Chicago, the diurnal variation was less extreme, but another pattern determines the situation with the lake breeze. The lake breeze corresponds to a shift in wind direction towards the east, i.e. from Lake Michigan during the late morning. It was found that certain elemental species

  7. Total reflection x-ray fluorescence spectrometers for multielemental analysis: status of commercial equipment

    International Nuclear Information System (INIS)

    Multi-elemental analysis by total reflection x-ray fluorescence spectrometry has evolved during two decades. At the present there are commercial equipment available for the chemical analysis in all kind of biological and mineral samples. The electronic industry has also been benefited from the scientific and technological developments in the field of TXRF. The basic components of the spectrometers can be summarized as follow: a) excitation source; b) geometric arrangement (optics) for collimation and monochromatization of the primary radiation; c) x-ray detector; d) hardware and software for operation of the instrument, data acquisition and spectral deconvolution to determine the concentrations of the element present in the sample (quantitative analysis). As optional there are manufacturers offering the conventional 45 degrees geometry for direct excitation of bulky liquid or solid samples. Personal communications of the author and the commercial brochures available at the moment of writing this presentation have allowed to list the following type of components used in the TXRF spectrometers for multi-elemental analysis (the devices used in the electronic industry to analyze silicon wafers are excluded). Excitation: high power x-ray tube, output from 1300 to 2000 watts; metal ceramic low power-ray tube, output up to 50 watts. Different anodes are used but molybdenum, tungsten and copper are frequent. The excitation systems can be customized according to the requirements of the laboratory. Detector: Si-Li semi-conductor liquid nitrogen cooled; silicon solid state thermoelectrically cooled (silicon drift detector SDD and Si-PIN diode). Optics: multilayer monochromator of Si-W or Ni-C; double multilayer monochromator. Electronics: spectroscopy amplifier, analog to digital converter adapted to a PC compatible computer with software in Windows environment for the whole operation of the spectrometer and for qualy/quantitative analysis of samples are standards in the

  8. Total internal reflection fluorescence (TIRF) microscopy for real-time imaging of nanoparticle-cell plasma membrane interaction

    DEFF Research Database (Denmark)

    Parhamifar, Ladan; Moghimi, Seyed Moien

    2012-01-01

    Nanoparticulate systems are widely used for site-specific drug and gene delivery as well as for medical imaging. The mode of nanoparticle-cell interaction may have a significant effect on the pathway of nanoparticle internalization and subsequent intracellular trafficking. Total internal reflection...

  9. Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

    Energy Technology Data Exchange (ETDEWEB)

    Mihucz, Victor G. [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); Moricz, Agnes M. [L. Eoetvoes University, Department of Chemical Technology and Environmental Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Kroepfl, Krisztina [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Szikora, Szilvia [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Tatar, Eniko [Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Parra, Lue Meru Marco [Universidad Centro-occidental Lisandro Alvarado, Decanato de Agronomia, Departamento de Quimica y Suelos Unidad de Analisis Instrumental, Apartado Postal 4076, Cabudare 3023 (Venezuela); Zaray, Gyula [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary) and Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary) and L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary)]. E-mail: zaray@ludens.elte.hu

    2006-11-15

    Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods.

  10. A plastic total internal reflection-based photoluminescence device for enzymatic biosensors

    Science.gov (United States)

    Thakkar, Ishan G.

    Growing concerns for quality of water, food and beverages in developing and developed countries drive sizeable markets for mass-producible, low cost devices that can measure the concentration of contaminant chemicals in water, food, and beverages rapidly and accurately. Several fiber-optic enzymatic biosensors have been reported for these applications, but they exhibit very strong presence of scattered excitation light in the signal for sensing, requiring expensive thin-film filters, and their non-planar structure makes them challenging to mass-produce. Several other planar optical waveguide-based biosensors prove to be relatively costly and more fragile due to constituent materials and the techniques involved in their fabrication. So, a plastic total internal reflection (TIR)-based low cost, low scatter, field-portable device for enzymatic biosensors is fabricated and demonstrated. The design concept of the TIR-based photoluminescent enzymatic biosensor device is explained. An analysis of economical materials with appropriate optical and chemical properties is presented. PMMA and PDMS are found to be appropriate due to their high chemical resistance, low cost, high optical transmittance and low auto-fluorescence. The techniques and procedures used for device fabrication are discussed. The device incorporated a PMMA-based optical waveguide core and PDMS-based fluid cell with simple multi-mode fiber-optics using cost-effective fabrication techniques like molding and surface modification. Several techniques of robustly depositing photoluminescent dyes on PMMA core surface are discussed. A pH-sensitive fluorescent dye, fluoresceinamine, and an O2-sensitive phosphorescent dye, Ru(dpp) both are successfully deposited using Si-adhesive gel-based as well as HydroThane-based deposition methods. Two different types of pH-sensors using two different techniques of depositing fluoresceinamine are demonstrated. Also, the effect of concentration of fluoresceinamine-dye molecules

  11. Grazing incidence reflectivity and total electron yield effects in soft x-ray absorption spectroscopy

    NARCIS (Netherlands)

    Alders, D; Hibma, T; Sawatzky, G.A; Cheung, K.C.; van Dorssen, G.E.; Roper, M.D.; Padmore, H.A.; van der Laan, G.; Vogel, J; Sacchi, M.

    1997-01-01

    We report on a study of grazing incidence absorption and reflection spectra of NiO in the region of the Ni 2p edge. The aim is to evaluate the distortion of the near edge spectrum by the critical angle behavior of individual components within the spectrum. This can be used to improve the separation

  12. Total reflection X-ray fluorescence trace mercury determination by trapping complexation: Application in advanced oxidation technologies

    Energy Technology Data Exchange (ETDEWEB)

    Custo, Graciela [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Litter, Marta I. [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Escuela de Posgrado, Universidad de General San Martin, San Lorenzo 3391 Villa Ballester, 1653. Prov. de Buenos Aires (Argentina); Rodriguez, Diana [Universidad Nacional de Lujan, Ruta 5 y 7. Prov. de Buenos Aires (Argentina); Vazquez, Cristina [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina) and Laboratorio de Quimica de Sistemas Heterogeneos, Facultad de Ingenieria, Universidad de Buenos Aires, P. Colon 850 (C1063ACU), Buenos Aires (Argentina)]. E-mail: Cristina.Vazquez@cnea.gov.ar

    2006-11-15

    It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 {mu}g/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these volatile species in liquid samples by using complexing agents is proposed. Acetate, oxalic acid, ethylenediaminetetracetic acid and ammonium pyrrolidine-dithiocarbamate were assayed for trapping the analytes into the solution during the preparation of the sample and onto the reflector during total reflection X-ray fluorescence measurements. The proposed method was applied to evaluate Hg concentration during TiO{sub 2}-heterogeneous photocatalysis, one of the most known advanced oxidation technologies. Advanced oxidation technologies are processes for the treatment of effluents in waters and air that involve the generation of very active oxidative and reductive species. In heterogeneous photocatalysis, Hg is transformed to several species under ultraviolet illumination in the presence of titanium dioxide. Total reflection X-ray fluorescence was demonstrated to be applicable in following the extent of the heterogeneous photocatalysis reaction by determining non-transformed Hg in the remaining solution.

  13. Total reflection X-ray fluorescence trace mercury determination by trapping complexation: Application in advanced oxidation technologies

    Science.gov (United States)

    Custo, Graciela; Litter, Marta I.; Rodríguez, Diana; Vázquez, Cristina

    2006-11-01

    It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 μg/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these volatile species in liquid samples by using complexing agents is proposed. Acetate, oxalic acid, ethylenediaminetetracetic acid and ammonium pyrrolidine-dithiocarbamate were assayed for trapping the analytes into the solution during the preparation of the sample and onto the reflector during total reflection X-ray fluorescence measurements. The proposed method was applied to evaluate Hg concentration during TiO 2-heterogeneous photocatalysis, one of the most known advanced oxidation technologies. Advanced oxidation technologies are processes for the treatment of effluents in waters and air that involve the generation of very active oxidative and reductive species. In heterogeneous photocatalysis, Hg is transformed to several species under ultraviolet illumination in the presence of titanium dioxide. Total reflection X-ray fluorescence was demonstrated to be applicable in following the extent of the heterogeneous photocatalysis reaction by determining non-transformed Hg in the remaining solution.

  14. Rapid evaluation and quantitative analysis of eugenol derivatives in essential oils and cosmetic formulations on human skin using attenuated total reflectance–infrared spectroscopy

    OpenAIRE

    Wang, Lai-Hao; Sung, Wei-Chien

    2011-01-01

    We studied the fragrances 4-allylbenzenes (eugenol, methyl eugenol, acetyl eugenol) as well as 4-propenylbenzenes (isoeugenol) in commercial essential oils using a fast and nondestructive attenuated total reflectance–infrared (ATR–IR) spectroscopy method. The method was based on ATR–IR utilizing partial least square regression. The calibrations were modeled in the characteristic region for eugenol (1430–1432 cm−1), isoeugenol (960–970 cm−1) and methyl eugenol (803–807 cm−1). The models were t...

  15. Total number albedo and average cosine of the polar angle of low-energy photons reflected from water

    Directory of Open Access Journals (Sweden)

    Marković Srpko

    2007-01-01

    Full Text Available The total number albedo and average cosine of the polar angle for water and initial photon energy range from 20 keV to 100 keV are presented in this pa per. A water shield in the form of a thick, homogenous plate and per pendicular incidence of the monoenergetic photon beam are assumed. The results were obtained through Monte Carlo simulations of photon reflection by means of the MCNP computer code. Calculated values for the total number albedo were compared with data previously published and good agreement was confirmed. The dependence of the average cosine of the polar angle on energy is studied in detail. It has been found that the total average cosine of the polar angle has values in the narrow interval of 0.66-0.67, approximately corresponding to the reflection angle of 48°, and that it does not depend on the initial photon energy.

  16. Use of Attenuated Total Reflectance Mid-Infrared Spectroscopy for Rapid Prediction of Amino Acids in Chinese Rice Wine.

    Science.gov (United States)

    Wu, Zhengzong; Xu, Enbo; Long, Jie; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

    2015-08-01

    The high content of amino acids of Chinese rice wine (CRW), especially essential amino acids makes it a food increasingly demanded by consumers. Rapid detection technique of amino acid content, which is an important quality and function index of CRW, is highly desirable for consumers, producers as well as administrative authorities. In this study, the potential of Fourier transform infrared spectroscopy (FT-IR) as a novel and rapid analytical technique to determine 17 free amino acids in CRW were investigated. Genetic algorithms (GA) and synergy interval partial least squares (SiPLS) were used to select the most efficient spectral variables to improve the prediction precision of the classic partial least squares (PLS) model constructed on the full-spectrum. The results demonstrated that compared with the PLS model using all wavelengths of FT-IR spectra, the prediction precision of model based on the spectral variables selected by GA and SiPLS was significantly improved, especially for arginine and proline. After systemic comparison and discussion, it was found that GA-SiPLS model achieved the best performance, with the correlation coefficient in calibration (R(2) (cal)) higher than 0.80 and the residual predictive deviation higher than 2.00 for all of the free amino acids analyzed in this study. The overall results confirmed that FT-IR combined with efficient variable selection algorithms is a method that may be useful to replace the traditional methods for routine analysis of free amino acids in CRW.

  17. Determination of Optical Constants in the Mid-Infrared Spectral Range by use of the Attenuated Total Reflection Method

    OpenAIRE

    Biliškov, N.

    2010-01-01

    Infrared (IR) spectroscopy is one of the most useful experimental methods in the investigation of hydrogen-bonded systems. However, application of transmission IR spectroscopy to aqueous systems is only of limited value due to the very strong water absorption. The necessity of very short pathlengths to obtain quantitative spectra is accompanied by very low reproducibility of the spectra obtained in such a way. However, in the last two decades, a reliable procedure which allows the calculation...

  18. Total Reducing Capacity in Aquifer Minerals and Sediments: Quantifying the Potential to Attenuate Cr(VI) in Groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Sisman, S. Lara [Univ. of Virginia, Charlottesville, VA (United States); Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-07-20

    Hexavalent chromium, Cr(VI), is present in the environment as a byproduct of industrial processes. Due to its mobility and toxicity, it is crucial to attenuate or remove Cr(VI) from the environment. The objective of this investigation was to quantify potential natural attenuation, or reduction capacity, of reactive minerals and aquifer sediments. Samples of reduced-iron containing minerals such as ilmenite, as well as Puye Formation sediments representing a contaminated aquifer in New Mexico, were reacted with chromate. The change in Cr(VI) during the reaction was used to calculate reduction capacity. This study found that minerals that contain reduced iron, such as ilmenite, have high reducing capacities. The data indicated that sample history may impact reduction capacity tests due to surface passivation. Further, this investigation identified areas for future research including: a) refining the relationships between iron content, magnetic susceptibility and reduction capacity, and b) long term kinetic testing using fresh aquifer sediments.

  19. Total Reducing Capacity in Aquifer Minerals and Sediments: Quantifying the Potential to Attenuate Cr(VI) in Groundwater

    International Nuclear Information System (INIS)

    Hexavalent chromium, Cr(VI), is present in the environment as a byproduct of industrial processes. Due to its mobility and toxicity, it is crucial to attenuate or remove Cr(VI) from the environment. The objective of this investigation was to quantify potential natural attenuation, or reduction capacity, of reactive minerals and aquifer sediments. Samples of reduced-iron containing minerals such as ilmenite, as well as Puye Formation sediments representing a contaminated aquifer in New Mexico, were reacted with chromate. The change in Cr(VI) during the reaction was used to calculate reduction capacity. This study found that minerals that contain reduced iron, such as ilmenite, have high reducing capacities. The data indicated that sample history may impact reduction capacity tests due to surface passivation. Further, this investigation identified areas for future research including: a) refining the relationships between iron content, magnetic susceptibility and reduction capacity, and b) long term kinetic testing using fresh aquifer sediments.

  20. Effect of weight fraction of different constituent elements on the total mass attenuation coefficients of biological materials

    Indian Academy of Sciences (India)

    Karamjit Singh; Charanjeet Singh; Parjit S Singh; Gurmel S Mudahar

    2002-07-01

    The mass attenuation coefficients, m, of biological materials have been studied as a function of weight fraction of constituent elements (hydrogen, carbon, oxygen and nitrogen). A considerable change in m is seen only in low energy region whereas no change is observed with the increasing percentage of constituent elements in high energy region up to 10 MeV. The results have been presented in graphical form.

  1. Effect of surface plasmon polaritons on the sensitivity of refractive index measurement using total internal reflection method

    Energy Technology Data Exchange (ETDEWEB)

    Roshan Entezar, S., E-mail: s-roshan@tabrizu.ac.ir

    2015-05-01

    The phase difference between two p-polarized and s-polarized plane waves which are reflected under total internal reflection from the base of a prism with a thin metal coating is studied. Typically such a quantity can be used to measure the refractive index of a test material using the total internal reflection method. It is shown that due to the excitation of surface plasmon polaritons at the interface between the tested dielectric material and the thin metal layer, the p-polarized light experiences a large phase shift which enlarges the phase difference between the p-polarized and the s-polarized waves. As a result, the sensitivity of refractive index measurement increases and the error in determining the refractive index decreases. - Highlights: • Phase difference of totally internally reflected p and s polarized beams is studied. • Excitation of the surface wave increases the phase shift of the p-polarized light. • The sensitivity of refractive index measurement increases by using a coated prism. • The error in determining the refractive index decreases using the coated prism.

  2. Controllable transmission and total reflection through an impedance-matched acoustic metasurface

    KAUST Repository

    Mei, Jun

    2014-12-02

    A general design paradigm for a novel type of acoustic metasurface is proposed by introducing periodically repeated supercells on a rigid thin plate, where each supercell contains multiple cut-through slits that are filled with materials possessing different refractive indices but the same impedance as that of the host medium. When the wavelength of the incident wave is smaller than the periodicity, the direction of the transmitted wave with nearly unity transmittance can be chosen by engineering the phase discontinuities along the transverse direction. When the wavelength is larger than the periodicity, even though the metasurface is impedance matched to the host medium, most of the incident energy is reflected back and the remaining portion is converted into a surface-bound mode. We show that both the transmitted wave control and the high reflection with the surface mode excitation can be interpreted by a unified analytic model based on mode-coupling theory. Our general design principle not only supplies the functionalities of reflection-type acoustic metasurfaces, but also exhibits unprecedented flexibility and efficiency in various domains of wave manipulation for possible applications in fields like refracting, collimating, focusing or absorbing wave energy.

  3. On the tunneling of full-vector X-Waves through a slab under frustrated total reflection condition

    KAUST Repository

    Salem, Mohamed

    2012-07-01

    Tunneling of full-vector X-Waves through a dielectric slab under frustrated total reflection condition is investigated. Full-vector X-Waves are obtained by superimposing transverse electric and magnetic polarization components, which are derived from the scalar X-Wave solution. The analysis of reflection and transmission at the dielectric interfaces is carried out analytically in a straightforward fashion using vector Bessel beam expansion. Investigation of the fields propagating away from the farther end of the slab (transmitted fields) shows an advanced (superluminal) transmission of the X-Wave peak. Additionally, a similar advanced reflection is also observed. The apparent tunneling of the peak is shown to be due to the phase shift in the fields\\' spectra and not to be causally related to the incident peak. © 2012 IEEE.

  4. Assessment of serum selenium levels in 2-month-old sucking calves using Total Reflection Technique

    International Nuclear Information System (INIS)

    The assessment of selenium status of livestock is an important aspect of production medicine as evidence for the influence of low Se levels on disease resistance in ruminants is reviewed with emphasis on susceptibility to various pathologies (such as infections, exudative diathesis, pneumonia, pancreatic degeneration). Additional evidence suggests that Se deficiency may cause muscular dystrophy in calves, while, severe deficiency has been associated with cardiomyopathy and even death. Serum Se content is a good indicator of the short term Se status and reflects the recent dietary intake of the element. Since Serum Se content is a good indicator of the short term status of the element and reflects the its recent dietary intake, the present work is aimed to determine Se concentration in serum from a group of 2 month old sucking calves suspected to be severely deficient. We used the TX 2000 X-ray spectrometer manufactured by Ital Structures. The energy resolution (FWHM) of the Si(Li) detector was 137 eV for Mn Kα. Among nuclear techniques the TXRF method is the best suitable for trace element analysis in liquid or dissolved samples and can deal much easier with elemental investigation. Physical basis of used analytical method, experimental set up and the sample preparation procedure are described. The concentration data obtained are presented and discussed

  5. Assessment of serum selenium levels in 2-month-old sucking calves using total reflection technique

    International Nuclear Information System (INIS)

    The assessment of selenium status of livestock is an important aspect of production medicine as evidence for the influence of low Se levels on disease resistance in ruminants is reviewed with emphasis on susceptibility to various pathologies (such as infections, exudative diathesis, pneumonia, pancreatic degeneration). Additional evidence suggests that Se deficiency may cause muscular dystrophy in calves, while, severe deficiency has been associated with cardiomyopathy and even death. Serum Se content is a good indicator of the short term Se status and reflects the recent dietary intake of the element. Since serum Se content is a good indicator of the short term status of the element and reflects the its recent dietary intake, the present work is aimed to determine Se concentration in serum from a group of 2 months old sucking calves suspected to be severely deficient. We used the TX 2000 X-ray spectrometer manufactured by Ital Structures. The energy resolution (FWHM) of the Si(Li) detector was 137 eV for Mn Kα. Among nuclear techniques the TXRF method is the best suitable for trace element analysis in liquid or dissolved samples and can deal much easier with elemental investigation. Physical basis of used analytical method, experimental set up and the sample preparation procedure are described. The concentration data obtained are presented and discussed. (author)

  6. l-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men.

    Science.gov (United States)

    Figueroa, Arturo; Alvarez-Alvarado, Stacey; Jaime, Salvador J; Kalfon, Roy

    2016-07-01

    Combined isometric exercise or metaboreflex activation (post-exercise muscle ischaemia (PEMI)) and cold pressor test (CPT) increase cardiac afterload, which may lead to adverse cardiovascular events. l-Citrulline supplementation (l-CIT) reduces systemic arterial stiffness (brachial-ankle pulse wave velocity (baPWV)) at rest and aortic haemodynamic responses to CPT. The aim of this study was to determine the effect of l-CIT on aortic haemodynamic and baPWV responses to PEMI+CPT. In all, sixteen healthy, overweight/obese males (age 24 (sem 6) years; BMI 29·3 (sem 4·0) kg/m2) were randomly assigned to placebo or l-CIT (6 g/d) for 14 d in a cross-over design. Brachial and aortic systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), aortic augmented pressure (AP), augmentation index (AIx), baPWV, reflection timing (Tr) and heart rate (HR) were evaluated at rest and during isometric handgrip exercise (IHG), PEMI and PEMI+CPT at baseline and after 14 d. No significant effects were evident after l-CIT at rest. l-CIT attenuated the increases in aortic SBP and wave reflection (AP and AIx) during IHG, aortic DBP, MAP and AIx during PEMI, and aortic SBP, DBP, MAP, AP, AIx and baPWV during PEMI+CPT compared with placebo. HR and Tr were unaffected by l-CIT in all conditions. Our findings demonstrate that l-CIT attenuates aortic blood pressure and wave reflection responses to exercise-related metabolites. Moreover, l-CIT attenuates the exaggerated arterial stiffness response to combined metaboreflex activation and cold exposure, suggesting a protective effect against increased cardiac afterload during physical stress. PMID:27160957

  7. 1. Latin American Workshop on Total Reflection X-Ray Fluorescence (TXRF) and its Applications: TARABANA 99. Programme and Abstracts

    International Nuclear Information System (INIS)

    It concerns about the advances in Total Reflection X-Ray Fluorescence (TXRF) instrumentation; structure, characteristic and potential of TXRF equipment used for chemical multielemental survey; TXRF: an approach to nano analysis; microanalytical investigation of environmental samples by TXRF spectrometry; TXRF of low Z elements; assessment of serum selenium levels in 2 month old sucking calves using TXRF: A powerful method to investigate the elemental composition of spheroids; environmental applications of TXRF; use of modifiers for the elimination in situ of chlorides in the analysis of TXRF; experimental methodology and analysis spectra for the determination of mercury by means of TXRF using amalgamation with gold; multielemental analysis of human amniotic fluid by use of Total Reflection X-Ray Fluorescence and rutherford forward scattering; determination of metal in samples of handmade penca; determination of oligo elements, platinum and relationship Zn/Cu in samples of blood serum and urine in oncological pediatric patient

  8. Progress of standardization activity of Total reflection X-Ray Fluorescence method ISO TC 201 W62

    International Nuclear Information System (INIS)

    The measurement of metal impurities on the surface of silicon wafer by Total reflection X-Ray Fluorescence is commonly accepted by the semiconductor industry ISO TC 201 W62 was organized in 1993 as a secretary country in Japan ISO 14706 specified a Total reflection X-Ray Fluorescence method for measurements of metal impurities on the silicon wafer surface with atomic surface density from 1x1010 atoms/cm2 to 1x1014 atoms/cm2 at Dec 2000. In ULSI manufacturing, the measurements for metal impurities of less than 1010 atoms/cm2 are currently required on the silicon wafer of Total reflection X-Ray Fluorescence chemical preparation method (DADD) has been adopted to collected and concentrate metal impurities into a small area on the surface of silicon wafer. In order to certificate the accuracy of quantification of metal impurities in the drying residue that is obtained by chemical preparation method we are going to specify this chemical preparation method. The results of the firsts round robin test RRT) carried out with three experimental conditions depended on each laboratories had pretty big measurement error the second RRT was done under the experimental conditions used with the recovery solution of HF(2%) H2O2(2%) and the addition of vanadium of scandium as a internal standard. 20 Laboratories (Japan: 11, US: 3, Europe: 6)gave a combination of the chemical preparation method and Total reflection X-Ray Fluorescence, AAS or ICP-MS results good reproducibility of less than 20 % Cv and repeatability of less than 10 % Cv

  9. Mapping of healthy oral mucosal tissue using diffuse reflectance spectroscopy: ratiometric-based total hemoglobin comparative study.

    Science.gov (United States)

    Hafez, Razan; Hamadah, Omar; Bachir, Wesam

    2015-11-01

    The objective of this study is to clinically evaluate the diffuse reflectance spectroscopy (DRS) ratiometric method for differentiation of normal oral mucosal tissues with different histological natures and vascularizations in the oral cavity. Twenty-one healthy patients aged 20-44 years were diagnosed as healthy and probed with a portable DRS system. Diffuse reflectance spectra were recorded in vivo in the range (450-650 nm). In this study, the following three oral mucosal tissues were considered: masticatory mucosa, lining mucosa, and specialized mucosa. Spectral features based on spectral intensity ratios were determined at five specific wavelengths (512, 540, 558, 575, and 620 nm). Total hemoglobin based on spectral ratios for the three anatomical regions have also been evaluated. The three studied groups representing different anatomical regions in the oral cavity were compared using analysis of variance and post hoc least significant difference tests. Statistical analysis showed a significant difference in the mean of diffuse spectral ratios between the groups (P oral sites in terms of total hemoglobin content. Diffuse reflectance spectroscopy might be used for creating a DRS databank of normal oral mucosal tissue with specific spectral ratios featuring the total hemoglobin concentrations. That would further enhance the discrimination of oral tissue for examining the histological nature of oral mucosa and diagnosis of early precancerous changes in the oral cavity based on non-invasive monitoring of neovascularization. PMID:25987341

  10. Resolution of Internal Total Reflection Scanning Near-field Optical Microscopy

    Institute of Scientific and Technical Information of China (English)

    GE Huayong; GUO Qizhi; TAN Weihan

    2002-01-01

    In this paper, the probe-sample interaction equation based on Mie′s scattering theory is derived, and the resolution of scanning near field optical microscopy is calculated numerically. The results show that the offset of far-field component to near-field component in total field plays an important role in the resolution and the size of samples also has influence on resolution.

  11. Surface characterization of selected polymer thin films by total-reflection x-ray fluorescence spectroscopy and x-ray reflectivity

    International Nuclear Information System (INIS)

    Development of available x-ray characterizations tools for grazing incidence techniques was done to be able to probe nano-size thin films. Alignment of a Philips x-ray powder diffractometer was improved to let it perform as an x-ray reflectometer. X-ray reflectometry was coupled with total-reflection x-ray fluorescence spectroscopy. Evaluation of the performance of this grazing incidence techniques was done by preparing polymer thin films of carboxymethylcellulose, carrageenan and polyvinylpyrrolidone (PVP). The thickness of the films were varied by varying the process parameters such as concentration, spin speed and spin time. Angle-dispersive total-reflection x-ray fluorescence spectroscopy profiles of three films showed film formation only in carrageenan and PVP. For both carrageenan and PVP, an increase in concentration yielded a corresponding increase in intensity of the fluorescent or scattered peaks. XRR profiles of carrageenan thin films yielded a mean value for the critical angle close to quartz substrate. Thickness measurements of the prepared carrageenan thin films showed that concentration was the main determinant for final film thickness over the other process parameters. Sulfur fluorescent intensity derived from the TXRF measurement showed a linear relationship with the measured thickness by XRR. For PVP, measured critical angle is lower than quartz. Poor adhesion of the polymer onto the substrate yielded a limited number of thickness measurements made from the XRR profiles. (Author)

  12. Recent results of synchrotron radiation induced total reflection X-ray fluorescence analysis at HASYLAB, beamline L

    Energy Technology Data Exchange (ETDEWEB)

    Streli, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria)]. E-mail: streli@ati.ac.at; Pepponi, G. [ITC-irst, Povo (Italy); Wobrauschek, P. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria); Jokubonis, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria); Falkenberg, G. [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22603 Hamburg (Germany); Zaray, G. [Institute of Inorganic and Applied Chemistry, 3 EOTVOS Univ, Budapest (Hungary); Broekaert, J. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Fittschen, U. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Peschel, B. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)

    2006-11-15

    At the Hamburger Synchrotronstrahlungslabor (HASYLAB), Beamline L, a vacuum chamber for synchrotron radiation-induced total reflection X-ray fluorescence analysis, is now available which can easily be installed using the adjustment components for microanalysis present at this beamline. The detector is now in the final version of a Vortex silicon drift detector with 50-mm{sup 2} active area from Radiant Detector Technologies. With the Ni/C multilayer monochromator set to 17 keV extrapolated detection limits of 8 fg were obtained using the 50-mm{sup 2} silicon drift detector with 1000 s live time on a sample containing 100 pg of Ni. Various applications are presented, especially of samples which are available in very small amounts: As synchrotron radiation-induced total reflection X-ray fluorescence analysis is much more sensitive than tube-excited total reflection X-ray fluorescence analysis, the sampling time of aerosol samples can be diminished, resulting in a more precise time resolution of atmospheric events. Aerosols, directly sampled on Si reflectors in an impactor were investigated. A further application was the determination of contamination elements in a slurry of high-purity Al{sub 2}O{sub 3}. No digestion is required; the sample is pipetted and dried before analysis. A comparison with laboratory total reflection X-ray fluorescence analysis showed the higher sensitivity of synchrotron radiation-induced total reflection X-ray fluorescence analysis, more contamination elements could be detected. Using the Si-111 crystal monochromator also available at beamline L, XANES measurements to determine the chemical state were performed. This is only possible with lower sensitivity as the flux transmitted by the crystal monochromator is about a factor of 100 lower than that transmitted by the multilayer monochromator. Preliminary results of X-ray absorption near-edge structure measurements for As in xylem sap from cucumber plants fed with As(III) and As(V) are

  13. Ganoderma lucidum total triterpenes attenuate DLA induced ascites and EAC induced solid tumours in Swiss albino mice.

    Science.gov (United States)

    Smina, T P; Mathew, J; Janardhanan, K K

    2016-01-01

    G. lucidum total triterpenes were assessed for its apoptosis-inducing and anti-tumour activities. The ability of the total triterpenes to induce apoptosis was evaluated in Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines. Total triterpenes were found to be highly cytotoxic to DLA and EAC cell lines with IC50 values 5 ± 0.32 and 7.9 ± 0.2 µg/ml respectively. Total triterpenes induced apoptosis in both cell lines which is evident from the DNA fragmentation assay. Anti-tumour activity was accessed using DLA induced solid and EAC induced ascites tumour models in Swiss albino mice. Administration of 10, 50 and 100 mg/kg b. wt. total triterpenes showed 11.86, 27.27 and 40.57% increase in life span of animals in ascites tumour model. Treatment with 10, 50 and 100 mg/kg b. wt. total triterpenes exhibited 76.86, 85.01 and 91.03% inhibition in tumour volume and 67.96, 72.38 and 77.90% inhibition in tumour weight respectively in the solid tumour model. The study reveals the significant dose-dependent anti-tumour activity of total triterpenes in both models. Total triterpenes were more active against the solid tumour than the ascites tumour. The anti-oxidant potential and ability to induce cell-specific apoptosis could be contributing to its anti-tumour activities. PMID:27188870

  14. Approximate analytical formulas for total cross sections and for mass attenuation coefficients of narrow gamma beams for 3 to 100 MeV

    International Nuclear Information System (INIS)

    Tabulated data by Storm and Israel for total cross sections and mass attenuation coefficients for narrow gamma beams of 3 to 100 MeV and elements with Z equal to 26 to 94 were approximated by an analytical formula analogous to the ultrarelativistic case of Compton scattering and pair creation. The reproduction accuracy of the tabulated data is better than 1 to 2% in a region of 3 to 60 MeV and better than 3 to 4% from 60 to 100 MeV. In the analytical formula three constants were needed for each Z, the tables of which are given. (author)

  15. Total reflection X-ray fluorescence analysis of trace-elements in candies marketed in Mexico

    International Nuclear Information System (INIS)

    Trace metals concentrations in food are significant for nutrition, due either to their nature or toxicity. Sweets, including chewing gum and candies, are not exactly a food, but they usually are unwearied consumed by children, the most vulnerable age-group to any kind of metal contamination in the food chain. The presence of relatively high concentrations of heavy metals such as Lead elicits concern since children are highly susceptible to heavy metals poisoning. Trace-metals concentrations were determined for six different flavors of a Mexican candy by means of Total X-ray Fluorescence Spectrometry. Triplicate samples of the various candy's flavours (strawberry, pineapple, lemon, blackberry, orange and chilli) were digested in 8 mL of a mix of supra-pure HNO3 and H2O2 (6 mL: 2 mL) in a microwave oven MARS-X. Results show the presence of essential and toxic elements such as Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, and Pb. All metal concentrations were higher and significantly different (α = 0.05) in chilli candy, compared to other candy flavours. Lead concentration fluctuated in the range of 0.102 to 0.342 μg g-1. A discussion about risk consumption and concentration allowed by Mexican and International Norms is made. As a part of the Quality Control Program, a NIST standard of 'Citrus Leaves' and a blank were treated in the same way.

  16. Quantitative Analysis of Total Petroleum Hydrocarbons in Soils: Comparison between Reflectance Spectroscopy and Solvent Extraction by 3 Certified Laboratories

    Directory of Open Access Journals (Sweden)

    Guy Schwartz

    2012-01-01

    Full Text Available The commonly used analytic method for assessing total petroleum hydrocarbons (TPH in soil, EPA method 418.1, is usually based on extraction with 1,1,2-trichlorotrifluoroethane (Freon 113 and FTIR spectroscopy of the extracted solvent. This method is widely used for initial site investigation, due to the relative low price per sample. It is known that the extraction efficiency varies depending on the extracting solvent and other sample properties. This study’s main goal was to evaluate reflectance spectroscopy as a tool for TPH assessment, as compared with three commercial certified laboratories using traditional methods. Large variations were found between the results of the three commercial laboratories, both internally (average deviation up to 20%, and between laboratories (average deviation up to 103%. Reflectance spectroscopy method was found be as good as the commercial laboratories in terms of accuracy and could be a viable field-screening tool that is rapid, environmental friendly, and cost effective.

  17. Total reflection X-ray fluorescence analysis of trace-elements in candies marketed in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, T., E-mail: tmc@servidor.unam.m [Facultad de Quimica, Departamento de Quimica Inorganica y Nuclear. Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510 (Mexico); Lartigue, J. [Facultad de Quimica, Departamento de Quimica Inorganica y Nuclear. Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510 (Mexico); Zarazua, G.; Avila-Perez, P. [National Institute of Nuclear Research. Ocoyoacac, Edo. de Mexico, 05045 (Mexico); Navarrete, M. [Facultad de Quimica, Departamento de Quimica Inorganica y Nuclear. Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510 (Mexico); Tejeda, S. [National Institute of Nuclear Research. Ocoyoacac, Edo. de Mexico, 05045 (Mexico)

    2010-06-15

    Trace metals concentrations in food are significant for nutrition, due either to their nature or toxicity. Sweets, including chewing gum and candies, are not exactly a food, but they usually are unwearied consumed by children, the most vulnerable age-group to any kind of metal contamination in the food chain. The presence of relatively high concentrations of heavy metals such as Lead elicits concern since children are highly susceptible to heavy metals poisoning. Trace-metals concentrations were determined for six different flavors of a Mexican candy by means of Total X-ray Fluorescence Spectrometry. Triplicate samples of the various candy's flavours (strawberry, pineapple, lemon, blackberry, orange and chilli) were digested in 8 mL of a mix of supra-pure HNO{sub 3} and H{sub 2}O{sub 2} (6 mL: 2 mL) in a microwave oven MARS-X. Results show the presence of essential and toxic elements such as Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, and Pb. All metal concentrations were higher and significantly different ({alpha} = 0.05) in chilli candy, compared to other candy flavours. Lead concentration fluctuated in the range of 0.102 to 0.342 {mu}g g{sup -1}. A discussion about risk consumption and concentration allowed by Mexican and International Norms is made. As a part of the Quality Control Program, a NIST standard of 'Citrus Leaves' and a blank were treated in the same way.

  18. A method for thickness determination of thin films of amalgamable metals by total-reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results.

  19. Achromatic and high-resolution full-field X-ray microscopy based on total-reflection mirrors.

    Science.gov (United States)

    Matsuyama, Satoshi; Emi, Yoji; Kino, Hidetoshi; Kohmura, Yoshiki; Yabashi, Makina; Ishikawa, Tetsuya; Yamauchi, Kazuto

    2015-04-20

    We developed an achromatic and high-resolution full-field X-ray microscope based on advanced Kirkpatrick-Baez mirror optics that comprises two pairs of elliptical mirrors and hyperbolic mirrors utilizing the total reflection of X-rays. Performance tests to investigate the spatial resolution and chromatic aberration were performed at SPring-8. The microscope clearly resolved the pattern with ~100-nm feature size. Imaging the pattern by changing the X-ray energy revealed achromatism in the wide energy range of 8-11 keV.

  20. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions

    International Nuclear Information System (INIS)

    Highlights: → Treatment with Clonorchis sinensis-derived total protein attenuates OVA-induced airway inflammation and AHR to methacholine. → Induction of CD4+CD25+Foxp3+ T cells and IL-10 along with suppression of splenocyte proliferation by C. sinensis-derived total protein. → C. sinensis-derived total protein interferes with the expression of co-stimulatory molecules in DCs. -- Abstract: Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4+CD25+Foxp3+ regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naive T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical relationship between the allergic immune response and

  1. Mapping of healthy oral mucosal tissue using diffuse reflectance spectroscopy: ratiometric-based total hemoglobin comparative study.

    Science.gov (United States)

    Hafez, Razan; Hamadah, Omar; Bachir, Wesam

    2015-11-01

    The objective of this study is to clinically evaluate the diffuse reflectance spectroscopy (DRS) ratiometric method for differentiation of normal oral mucosal tissues with different histological natures and vascularizations in the oral cavity. Twenty-one healthy patients aged 20-44 years were diagnosed as healthy and probed with a portable DRS system. Diffuse reflectance spectra were recorded in vivo in the range (450-650 nm). In this study, the following three oral mucosal tissues were considered: masticatory mucosa, lining mucosa, and specialized mucosa. Spectral features based on spectral intensity ratios were determined at five specific wavelengths (512, 540, 558, 575, and 620 nm). Total hemoglobin based on spectral ratios for the three anatomical regions have also been evaluated. The three studied groups representing different anatomical regions in the oral cavity were compared using analysis of variance and post hoc least significant difference tests. Statistical analysis showed a significant difference in the mean of diffuse spectral ratios between the groups (P spectroscopy might be used for creating a DRS databank of normal oral mucosal tissue with specific spectral ratios featuring the total hemoglobin concentrations. That would further enhance the discrimination of oral tissue for examining the histological nature of oral mucosa and diagnosis of early precancerous changes in the oral cavity based on non-invasive monitoring of neovascularization.

  2. Light-trap design using multiple reflections and solid-angle attenuation - Application to a spaceborne electron spectrometer

    Science.gov (United States)

    Herrero, Federico A.

    1992-01-01

    The design and performance of a new light trap for a spaceborne electron spectrometer are described. The light trap has a measured photon-rejection ratio of 2 x 10 exp -11, allowing only one in 5 x 10 exp 10 incident photons to reach the sensitive area of the instrument. This rejection is more than sufficient because the ambient UV in earth orbit requires a rejection no better than 10 exp -8 to maintain the photon interference to less than 10 count/s. The light trap uses triple reflections to keep most of the light passing through the entrance slit away from the sensitive area of the spectrometer. It is shown that the average reflectance of all the internal surfaces must be less than 0.006, which is consistent with the data on the black coating applied to all surfaces. The analysis makes it possible to compare the photon contributions of each of the internal reflecting areas and to estimate the effective scattering width of the metallic electrode edge.

  3. Attenuation of global ultraviolet and visible irradiance over Greece during the total solar eclipse of 29 March 2006

    Directory of Open Access Journals (Sweden)

    A. Kazantzidis

    2007-12-01

    Full Text Available The variability of ultraviolet and photosynthetically active radiation (PAR during the total solar eclipse of 29 March 2006 was examined in this study. The measurements from NILU-UV multichannel radiometers at 7 stations of the Greek UV Network were used, where the maximum eclipse percentage ranged from 73.1% to 94.8%. In addition, an extra instrument was established at a remote Greek island, Kastelorizo, which was within the Moon's umbral shadow. The reduction of irradiance at 305 and 312 nm relative to non-eclipse conditions at all sites was almost 1.5 times more than the corresponding decrease in the UVA and visible part of the spectrum and reached 98% for eclipse percentage equal to 94%. The availability of several instruments in close proximity to the path of the umbral shadow provided a challenging test for the models. The measured changes in UV and visible irradiance were compared with 1-D model calculations accounting for the limb darkening effect. The agreement between measurements and modeled values at all sites is within 3% for eclipse percentages of less than 30% and becomes worse as the eclipse progresses. The 1-D model reproduced the spectral effect of the eclipse in UVA and PAR wavelength regions within 3% for eclipse percentages up to 50%, but only the half of the observed change was captured as the eclipse progressed. At three sites, where the eclipse maximum was more than 94%, the measured irradiance at 305 nm for eclipse percentages of more than 85% decreased with slower rates than for longer wavelengths. As a result, the total ozone values, derived from the 305/320 nm ratios, apparently decreased significantly for high eclipse percentages. The effect is similar at all three sites, but the interpretation of this observation remains a challenge. Comparison results with 3-D model calculations shortly before, during and shortly after totality were performed for the first time and revealed an agreement with measurements

  4. Total reflection x-ray fluorescence spectroscopy as a tool for evaluation of iron concentration in ferrofluids and yeast samples

    Science.gov (United States)

    Kulesh, N. A.; Novoselova, I. P.; Safronov, A. P.; Beketov, I. V.; Samatov, O. M.; Kurlyandskaya, G. V.; Morozova, M.; Denisova, T. P.

    2016-10-01

    In this study, total reflection x-ray fluorescent (TXRF) spectrometry was applied for the evaluation of iron concentration in ferrofluids and biological samples containing iron oxide magnetic nanoparticles obtained by the laser target evaporation technique. Suspensions of maghemite nanoparticles of different concentrations were used to estimate the limitation of the method for the evaluation of nanoparticle concentration in the range of 1-5000 ppm in absence of organic matrix. Samples of single-cell yeasts grown in the nutrient media containing maghemite nanoparticles were used to study the nanoparticle absorption mechanism. The obtained results were analyzed in terms of applicability of TXRF for quantitative analysis in a wide range of iron oxide nanoparticle concentrations for biological samples and ferrofluids with a simple established protocol of specimen preparation.

  5. Use of total-reflection X-ray fluorescence in search of a biomonitor for environmental pollution in Vietnam

    Science.gov (United States)

    Brauer, Hans; Wagner, Annemarie; Boman, Johan; Viet Binh, Doan

    2001-11-01

    The concentration of trace elements in tissues of several animals collected in the Ha Nam province, approximately 40 km south of Hanoi, Vietnam, has been investigated using total-reflection X-ray fluorescence analysis. We find that the freshwater mussel is probably the optimal choice of biomonitor for the pollution situation in Vietnam, but the freshwater crab, the toad and the catfish are also good candidates. The krait is probably also well suited for this purpose. It is shown that since several elements show a more or less pronounced accumulation tendency in a particular tissue it can be of great use to determine the levels in different tissues. When selecting an organism to be used as a biomonitor, other factors besides the mere concentration of trace elements must be considered, for instance the abundance and feeding habits.

  6. Application of a portable total reflection x-ray fluorescence spectrometer to a trace elemental analysis of wines

    International Nuclear Information System (INIS)

    A portable total reflection X-ray fluorescence (TXRF) spectrometer has been applied to a trace elemental analysis of wines. Sulfur, K, Mn, Fe, and Rb were detected. These five elements were quantified by using 1 ppm of Co as an internal standard. The quantified concentrations ranged from sub-ppm to several hundred ppm. Because of organic substances in wines, the scattering of the incident X-rays from the dry residues of wines becomes strong. Therefore, a high spectral background appears in TXRF spectra of wines. Because of this background, relative standard deviations of the quantified concentrations were from 4 to 28%. Although the high spectral background appeared in the TXRF spectra of the wines, a detection limit down to several tens of ppb was achieved. The present portable spectrometer can be applied to screening for trace elements in wines before an accurate and precise analysis using a large elemental analyzer. (author)

  7. In-situ analysis of fruit anthocyanins by means of total internal reflectance, continuous wave and time-resolved spectroscopy

    Science.gov (United States)

    Zude, Manuela; Spinelli, Lorenzo; Dosche, Carsten; Torricelli, Alessandro

    2009-08-01

    In sweet cherry (Prunus avium), the red pigmentation is correlated with the fruit maturity stage and can be measured by non-invasive spectroscopy. In the present study, the influence of varying fruit scattering coefficients on the fruit remittance spectrum (cw) were corrected with the effective pathlength and refractive index in the fruit tissue obtained with distribution of time-of-flight (DTOF) readings and total internal reflection fluorescence (TIRF) analysis, respectively. The approach was validated on fruits providing variation in the scattering coefficient outside the calibration sample set. In the validation, the measuring uncertainty when non-invasively analyzing fruits with cw method in comparison with combined application of cw, DTOF, and TIRF measurements showed an increase in r2 up to 22.7 % with, however, high errors in all approaches.

  8. Asymmetric structure of germanene on an Al(111) surface studied by total-reflection high-energy positron diffraction

    Science.gov (United States)

    Fukaya, Yuki; Matsuda, Iwao; Feng, Baojie; Mochizuki, Izumi; Hyodo, Toshio; Shamoto, Shin-ichi

    2016-09-01

    The structure of germanene on an Al(111) surface has been experimentally investigated using the total-reflection high-energy positron diffraction (TRHEPD) method. The observed spot intensities are asymmetric, revealing no mirror symmetry in the atomic coordinates of germenene with respect to the direction. Quantitative TRHEPD rocking curve analysis, based on dynamical diffraction theory, has revealed that the germanene layer has a 3 × 3 structure with asymmetrical buckling due to the protrusion of one of the Ge atoms in the unit cell, which is unlike the structural model proposed in previous studies. The magnitude of the buckling was found to be 0.94 Å, and the spacing between the germanene and the Al(111) substrate to be 2.51 Å. The new structure proposed in the present investigations, though different from that reported in studies before, does not contradict the other characteristics which were found experimentally in the previous studies.

  9. Practical guidelines for best practice on Total Reflection X-ray Fluorescence spectroscopy: Analysis of aqueous solutions

    Science.gov (United States)

    Riaño, Sofía; Regadío, Mercedes; Binnemans, Koen; Vander Hoogerstraete, Tom

    2016-10-01

    Despite the fact that Total Reflection X-ray Fluorescence (TXRF) is becoming more and more popular as a quantification technique in analytical chemistry due to its simplicity and robustness, there are still some key aspects related to the sample preparation that need to be improved. In this work, the effect of different parameters is investigated: measurement time, carrier position, sample volume and sample drying time. The measurement time and the sample volume on the carriers mainly affect the recovery rate and relative standard deviation of the quantified metal from aqueous solutions. The most important parameters that play a fundamental role in the calibration of a TXRF machine such as choice of the standard element and concentration ratio between the analyte and the standard are discussed. Practical and easy guidelines for the correct preparation of aqueous samples are presented. These can be used by both less and more experienced TXRF users, interested in measuring metal ion concentrations in aqueous samples.

  10. Fish samples as bioindicator of environmental quality: synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Vives, Ana Elisa Sirito de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Brienza, Sandra Maria Boscolo [Universidade Metodista de Piracicaba (UNIMEP), SP (Brazil). Faculdade de Ciencias Matematicas, da Natureza e de Tecnologia da Informacao]. E-mail: sbrienza@unimep.br; Zucchi, Orgheda Luiza Araujo Domingues [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio Franco do [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: virgilio@cena.usp.br

    2005-07-01

    In this study fish were used as bioindicators of environmental contamination. The species were collected in Piracicaba River, Sao Paulo state, Brazil and the toxic elements concentrations were determined in muscle tissue and viscus (liver, intestine and stomach) by Synchrotron Radiation Total Reflection X-Ray Fluorescence Analysis (SR-TXRF). Were determined the elements Ti, Cr, Mn, Fe, Ni, Cu, Zn and Ba. The results were compared with values established by Brazilian Legislation for general food. The elements concentrations evidenced potential risk to human health and environmental quality alteration of the studied area. The measurements were realized at the 'Laboratorio Nacional de Luz Sincrotron' (LNLS) located in Campinas, Sao Paulo State, Brazil. (author)

  11. A total internal reflection fluorescence microscopy study of mass diffusion enhancement in water-based alumina nanofluids

    Science.gov (United States)

    Veilleux, Jocelyn; Coulombe, Sylvain

    2010-11-01

    Mass diffusion of rhodamine 6G (R6G) in water-based alumina nanofluids is studied by means of total internal reflection fluorescence (TIRF) microscopy. We report a mass diffusivity enhancement that reaches an order of magnitude in a 2 vol % nanofluid when compared to the value in deionized water. Since experiments were performed with positively charged R6G, interfacial complexation between the dye and the nanoparticles was not observed. The effect of local density variations on mass diffusivity measurements is also addressed. An explanation for the enhancement of mass diffusion is presented using arguments based on dispersion, and it is shown that it correctly describes the order of magnitude differences between the thermal conductivity and mass diffusivity enhancements reported in the literature.

  12. Elemental concentration analysis in the brain of young and old Wistar rats by total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, Renata F.B.; Jesus, Edgar F.O. de; Lopes, Ricardo T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Nuclear Instrumentation Lab.]. E-mail: renata@lin.ufrj.br; Anjos, Marcelino J. dos [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Physics Inst.]. E-mail: marcelin@lin.ufrj.br; Carmo, Maria G.T. do [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Nutrition Inst.; Rocha, Monica S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. of Basics and Clinic Pharmacy; Moreira, Silvana [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Civil Engineering Dept.; Martinez, Ana M.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. of Histology and Embryology

    2007-07-01

    It is well known that aging is associated with neurobehavioral deficits. The aging process of human brain is characterized by progressive neuronal loss. Furthermore, certain brain areas are more vulnerable to neuronal degeneration than others, reflecting an altered resistance to stress of the tissue itself and/or the lack of adequate immunological defense mechanisms in these regions. About the elemental levels in the brain, it is known that the excess ou deficiency of some elements are toxic for human healthy, being also related to several neurodegenerative diseases. In this way, the main goal of this work was to determine the elemental concentration in the hippocampus of young and old male (n = 10) and female (n = 10) Wistar rats by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). These measurements were carried out at XRF beam line at Light Synchrotron Brazilian Laboratory, Campinas, Brazil. About the results, we could observe that Al, Fe, Cu, Zn and Br levels were higher in the hippocampus of the old female rats than the young ones. On the other hand, only Cu levels were higher in the hippocampus of the old male rats than the young ones. Therefore, the aging of the hippocampus of the female rats can be characterized by an accumulate for Al, Fe, Cu, Zn and Br. The excess in these elements levels are also associated with several neurodegenerative disorders, such as Alzheimer' disease, Parkinson's disease and Huntington's disease. (author)

  13. Determination of heavy metals in macrozoobenthos from the rivers Tisza and Szamos by total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Woelfl, S. [Universidad Austral de Chile, Instituto de Zoologia, Casilla 567, Valdivia (Chile)]. E-mail: swoelfl@uach.cl; Mages, M. [Helmhotz Centre for Environmental Research (UFZ), Department of River Ecology, Brueckstrasse 3a, D-39114, Magdeburg (Germany); Ovari, M. [Ovari, M. Eoetvoes University, Department of Organic Chemistry, H-1117, Budapest, Pazmany P. stny. 1/a (Hungary); Geller, W. [Helmhotz Centre for Environmental Research (UFZ), Department of River Ecology, Brueckstrasse 3a, D-39114, Magdeburg (Germany)

    2006-11-15

    In 2000, accidents in the Romanian mining industry in key catchment areas led to heavy metal contamination of the Hungarian rivers Tisza and Szamos resulting in substantial heavy metal loads in several sediments of the upper river basins. This enhanced metal content might have been bioaccumulated in benthic organisms during the following years. Therefore, the aim of this study was to test, whether the zoobenthic fauna showed an enhanced metal content 3 years after the industrial accident. Macrozoobenthic insect larvae (chironomids) were sampled 100 m below and above the confluent site of the rivers Tisza and Szamos during summer 2003 and for comparison purpose also in the river Maros, a tributary of the Tisza river, during 2005. In order to determine their heavy metal content, single specimens were prepared and analysed by Total Reflection X-ray Fluorescence Spectrometry (TRXF) according to the modified dry method. Fe was much lower and Mn and Zn much higher concentrated in benthos from the more contaminated Szamos river compared to the Tisza and Maros rivers. In this sense, the benthic organisms reflected very well the enhanced metal concentrations in the contaminated rivers being suitable as bioindicators of metal contamination. However, the sediment bioaccumulation factor was low at all sampling sites indicating a low bioavailability of trace metals for benthic organisms.

  14. p38 MAPK Inhibitor Insufficiently Attenuates HSC Senescence Administered Long-Term after 6 Gy Total Body Irradiation in Mice

    Directory of Open Access Journals (Sweden)

    Lu Lu

    2016-06-01

    Full Text Available Senescent hematopoietic stem cells (HSCs accumulate with age and exposure to stress, such as total-body irradiation (TBI, which may cause long-term myelosuppression in the clinic. However, the methods available for long-term myelosuppression remain limited. Previous studies have demonstrated that sustained p38 mitogen-activated protein kinases (p38 MAPK activation in HSCs following exposure to TBI in mice and the administration of its inhibitor twenty-four hours after TBI may partially prevent long-term myelosuppression. However, long-term myelosuppression is latent and identified long after the administration of radiation. In this study, we investigated the effects of SB203580 (a small molecule inhibitor of p38 MAPK on long-term myelosuppression induced by TBI. Mice with hematopoietic injury were injected intraperitoneally with SB203580 every other day five times beginning 70 days after 6 Gy of 137Cs γ ray TBI. Our results at 80 days demonstrated that SB203580 did not significantly improve the TBI-induced long-term reduction of peripheral blood cell and bone marrow nucleated cell (BMNC counts, or defects in hematopoietic progenitor cells (HPCs and HSC clonogenic function. SB203580 reduced reactive oxygen species (ROS production and p-p38 expression; however, SB203580 had no effect on p16 expression in the HSCs of mice. In conclusion, these findings suggest that treatment with SB203580 70 days after TBI in mice inhibits the ROS-p38 oxidative stress pathway; however, it has no therapeutic effect on long-term myelosuppression induced by TBI.

  15. Glutamine-supplemented total parenteral nutrition attenuates plasma interleukin-6 in surgical patients with lower disease severity

    Institute of Scientific and Technical Information of China (English)

    Ming-Tsan Lin; Sung-Pao Kung; Sung-Ling Yeh; Koung-Yi Liaw; Ming-Yang Wang; Ming-Liang Kuo; Po-Houng Lee; Wei-Jao Chen

    2005-01-01

    AIM: To evaluate whether the effect of Gln dipeptideenriched total parenteral nutrition (TPN) on postoperative cytokine alteration depended on the disease severity of surgical patients.METHODS: Forty-eight patients with major abdominal surgery were allocated to two groups to receive isonitrogenous (0.228 g nitrogen/kg per d) and isocaloric(30 kcal/kg per d) TPN for 6 d. Control group (Conv)using conventional TPN solution received 1.5 g amino adds/kg per day, whereas the test group received 0.972 g amino acids/kg per day and 0.417 g L-alanyl-L-glutamine(Ala-Gln)/kg per day. Blood samples were collected on d 1 and d 6 postoperatively for plasma interleukin (IL)-2,IL-6, IL-8, and interferon (IFN)-γ analysis.RESULTS: Plasma IL-2 and IFN-γ were not detectable.IL-6 concentrations were significantly lower on the 6th postoperative day in the Ala-Gln group than those in the Conv group in patients with APACHE Ⅱ≤6, whereas no difference was noted in patients with APACHE Ⅱ>6. There was no difference in IL-8 levels between the two groups.No difference in cumulative nitrogen balance was observed on d 2-5 after the operation between the two groups(Ala-Gln -3.2±1.6 g vs Conv -6.5±2.7 g). A significant inverse correlation was noted between plasma IL-6 levels and cumulative nitrogen balance postoperatively in the Ala-Gln group, whereas no such correlation was observed in the Conv group.CONCLUSION: TPN supplemented with Gln dipeptide had no effect on plasma IL-8 levels after surgery. However,Gln supplementation had a beneficial effect on decreasing systemic IL-6 production after surgery in patients with low admission illness severity, and lower plasma IL-6 may improve nitrogen balance in patients with abdominal surgery when Gln was administered.

  16. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Young-Il [Div. of Malaria and Parasitic Diseases, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of); Kim, Seung Hyun [Div. of AIDS, National Institute of Health, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of); Ju, Jung Won; Cho, Shin Hyeong; Lee, Won Ja [Div. of Malaria and Parasitic Diseases, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of); Park, Jin Wook; Park, Yeong-Min [Dept. of Microbiology and Immunology, College of Medicine, Pusan National University, Yang-San (Korea, Republic of); Lee, Sang Eun, E-mail: ondalgl@cdc.go.kr [Div. of Malaria and Parasitic Diseases, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of)

    2011-04-22

    Highlights: {yields} Treatment with Clonorchis sinensis-derived total protein attenuates OVA-induced airway inflammation and AHR to methacholine. {yields} Induction of CD4{sup +}CD25{sup +}Foxp3{sup +} T cells and IL-10 along with suppression of splenocyte proliferation by C. sinensis-derived total protein. {yields} C. sinensis-derived total protein interferes with the expression of co-stimulatory molecules in DCs. -- Abstract: Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4{sup +}CD25{sup +}Foxp3{sup +} regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naive T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical

  17. Herschel PEP/HerMES: the redshift evolution (0 ≤ z ≤ 4) of dust attenuation and of the total (UV+IR) star formation rate density

    Science.gov (United States)

    Burgarella, D.; Buat, V.; Gruppioni, C.; Cucciati, O.; Heinis, S.; Berta, S.; Béthermin, M.; Bock, J.; Cooray, A.; Dunlop, J. S.; Farrah, D.; Franceschini, A.; Le Floc'h, E.; Lutz, D.; Magnelli, B.; Nordon, R.; Oliver, S. J.; Page, M. J.; Popesso, P.; Pozzi, F.; Riguccini, L.; Vaccari, M.; Viero, M.

    2013-06-01

    Using new homogeneous luminosity functions (LFs) in the far-ultraviolet (FUV) from VVDS and in the far-infrared (FIR) from Herschel/PEP and Herschel/HerMES, we studied the evolution of the dust attenuation with redshift. With this information, we were able to estimate the redshift evolution of the total (FUV + FIR) star formation rate density (SFRDTOT). By integrating SFRDTOT, we followed the mass building and analyzed the redshift evolution of the stellar mass density (SMD). This article aims at providing a complete view of star formation from the local Universe to z ~ 4 and, using assumptions on earlier star formation history, compares this evolution with previously published data in an attempt to draw a homogeneous picture of the global evolution of star formation in galaxies. Our main conclusions are that: 1) the dust attenuation AFUV is found to increase from z = 0 to z ~ 1.2 and then starts to decrease until our last data point at z = 3.6; 2) the estimated SFRD confirms published results to z ~ 2. At z > 2, we observe either a plateau or a small increase up to z ~ 3 and then a likely decrease up to z = 3.6; 3) the peak of AFUV is delayed with respect to the plateau of SFRDTOT and a probable origin might be found in the evolution of the bright ends of the FUV and FIR LFs; 4) using assumptions (exponential rise and linear rise with time) for the evolution of the star formation density from z = 3.6 to zform = 10, we integrated SFRDTOT and obtained a good agreement with the published SMDs. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  18. Structure, characteristics and potential of commercial equipment Total Reflection X Ray Fluorescence for multielemental chemical analysis: Current State

    International Nuclear Information System (INIS)

    The method Total Reflection X-Ray Fluorescence for chemical multielemental analysis has evolved in the last years with the availability of commercial systems for applications in the field of electronics and chemical multielemental analysis in samples of mineral and biological origin. The basic components of these equipment cam be summarized in a system of excitement, a geometric arrangement (optics) for collimate and monochromatize the primary radiation, a X-rays detector, and the electronic si stem for spectral data acquisition including the software for spectra unfolding, qualitative and quantitative analysis, and the complete instrument operation. Additionally the makers offer the conventional 45 degrees geometry for the excitement solid and liquid samples of bigger volume in direct form. The available bibliographical and commercial information to the moment of preparing this lecture, basically reports the following types of components for the X-rays spectrometers in geometry of total reflection chemical multielemental analysis (they are excluded those RTFX equipment dedicated to the electronic industry for quality control of Si wafers purity used for the production of circuits (chips). Excitation: X-rays tube of high vacuum with power among 1300 to 2000 watts and different types of anode; X-rays ceramic metal tube, with power up to 40 watts, and anode of molybdenum, tug steno, etc. Detection: detector semiconductor of silicon-lithium cooled with liquid nitrogen; detector of solid state silicon cooled electrically (Si-PI N diode or detector of diffused silicon Sdd). Optics: multi stratum monochromator; multi stratum Ni-C monochromator; double multi stratum monochromator. Electronic: spectroscopical amplifier espectroscopico and ana logical digital convertor adapted to a personal computer IBM compatible, with software for qualitative and quantitative analysis of samples by means of Windows, and for the complete operation of the analyzer from the Pc. In this work

  19. Variable laser attenuator

    Science.gov (United States)

    Foltyn, Stephen R.

    1988-01-01

    The disclosure relates to low loss, high power variable attenuators comprng one or more transmissive and/or reflective multilayer dielectric filters. The attenuator is particularly suitable to use with unpolarized lasers such as excimer lasers. Beam attenuation is a function of beam polarization and the angle of incidence between the beam and the filter and is controlled by adjusting the angle of incidence the beam makes to the filter or filters. Filters are selected in accordance with beam wavelength.

  20. Determination of platinum group metal catalyst residues in active pharmaceutical ingredients by means of total reflection X-ray spectrometry

    Science.gov (United States)

    Marguí, Eva; Queralt, Ignasi; Hidalgo, Manuela

    2013-08-01

    The control of metal catalyst residues (i.e., platinum group metals (PGMs)) in different stages of the manufacturing processes of the active pharmaceutical ingredients (APIs) and, especially, in the final product is crucial. For API specimens, there are strict guidelines to limit the levels of metal residues based on their individual levels of safety concern. For PGMs the concentration limit has been established at 10 mg/kg in the API. Therefore great effort is currently being devoted to the development of new and simple procedures to control metals in pharmaceuticals. In the present work, an analytical methodology based on benchtop total reflection X-ray fluorescence spectrometry (TXRF) has been developed for the rapid and simple determination of some PGM catalyst impurities (Rh, Pd, Ir and Pt) in different types of API samples. An evaluation of different sample treatments (dissolution and digestion of the solid pharmaceutical samples) has been carried out and the developed methodologies have been validated according to the analytical parameters to be considered and acceptance criteria for PGM determination according to the United States Pharmacopeia (USP). Limits of quantification obtained for PGM metals were in the range of 2-4 mg/kg which are satisfactory according to current legislation. From the obtained results it is shown that the developed TXRF method can be implemented in the pharmaceutical industries to increase productivity of the laboratory; offering an interesting and complementary analytical tool to other atomic spectroscopic methods.

  1. Determination of arsenic in water samples by Total Reflection X-Ray Fluorescence using pre-concentration with alumina

    International Nuclear Information System (INIS)

    The determination of arsenic in water samples requires techniques of high sensitivity. Total Reflection X-Ray Fluorescence (TXRF) allows the determination but a prior separation and pre-concentration procedure is necessary. Alumina is a suitable substrate for the selective separation of the analytes. A method for separation and pre-concentration in alumina, followed by direct analysis of the alumina is evaluated. Quantification was performed using the Al-Kα and Co-Kα lines as internal standard in samples prepared on an alumina matrix, and compared to a calibration with aqueous standards. Artificial water samples of As (III) and As (V) were analyzed after the treatment. Fifty milliliters of the sample at ppb concentration levels were mixed with 10 mg of alumina. The pH, time and temperature were controlled. The alumina was separated from the slurry by centrifugation, washed with de-ionized water and analyzed directly on the sample holder. A pre-concentration factor of 100 was found, with detection limit of 0.7 μgL-1. The percentage of recovery was 98% for As (III) and 95% for As (V) demonstrating the suitability of the procedure.

  2. Multielemental analysis of human amniotic fluid by use of Total Reflection X-Ray Fluorescence and Rutherford Forward Scattering

    International Nuclear Information System (INIS)

    Full text: Correlation studies between the concentrations of certain elements present in human amniotic fluid (A F) and fetal disorders are important. There is a need for a technique or a group of complementary techniques for the reliable elemental analysis of A F. In order to study the reliability of Total Reflection X-Ray Fluorescence (TXRF), a comparison between TXRF and the well established technique of Proton Induced X-Ray Emission (PIXE) has been carried out by measuring the concentrations of Cl, K, Ca, Fe, Cu, Zn and Br in 10 common samples of A F. Different degrees of consistency have been obtained depending on the element being analyzed. There is a need to establish the experimental conditions under which a complete agreement between TXRF and PIXE is achieved. A common weakness of TXRF and PIXE is the difficulty to obtain adequate signals from elements lighter than Aluminum. To overcome this problem, a method based on Rutherford Forward Scattering (RFS) for the quantification of elements as light as Lithium is under development. Details on the experimental configuration (beam type, beam energy, detector angle, sample preparation, etc) that leads to an appropriate mass separation by using RFS will be given. Both TXRF and RFS are extremely convenient for correlating physical and medical data because they are non-destructive multielemental techniques which require small amounts of the sample to be analyzed

  3. Determination of arsenic in water samples by Total Reflection X-Ray Fluorescence using pre-concentration with alumina

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Haydn [Laboratorio de Fisica Nuclear, Dpto. De Fisica, Universidad Simon Bolivar, Sartenejas, Baruta (Venezuela, Bolivarian Republic of); Marco Parra, Lue-Meru, E-mail: luemerumarco@yahoo.e [Universidad Centroccidental Lisandro Alvarado, Dpto. Quimica y Suelos, Decanato de Agronomia, Tarabana, Cabudare, Edo.Lara (Venezuela, Bolivarian Republic of); Bennun, Leonardo [Universidad de Concepcion, Concepcion (Chile); Greaves, Eduardo D. [Laboratorio de Fisica Nuclear, Dpto. De Fisica, Universidad Simon Bolivar, Sartenejas, Baruta (Venezuela, Bolivarian Republic of)

    2010-06-15

    The determination of arsenic in water samples requires techniques of high sensitivity. Total Reflection X-Ray Fluorescence (TXRF) allows the determination but a prior separation and pre-concentration procedure is necessary. Alumina is a suitable substrate for the selective separation of the analytes. A method for separation and pre-concentration in alumina, followed by direct analysis of the alumina is evaluated. Quantification was performed using the Al-K{alpha} and Co-K{alpha} lines as internal standard in samples prepared on an alumina matrix, and compared to a calibration with aqueous standards. Artificial water samples of As (III) and As (V) were analyzed after the treatment. Fifty milliliters of the sample at ppb concentration levels were mixed with 10 mg of alumina. The pH, time and temperature were controlled. The alumina was separated from the slurry by centrifugation, washed with de-ionized water and analyzed directly on the sample holder. A pre-concentration factor of 100 was found, with detection limit of 0.7 {mu}gL{sup -1}. The percentage of recovery was 98% for As (III) and 95% for As (V) demonstrating the suitability of the procedure.

  4. Planar solar concentrator featuring alignment-free total-internal-reflection collectors and an innovative compound tracker.

    Science.gov (United States)

    Teng, Tun-Chien; Lai, Wei-Che

    2014-12-15

    This study proposed a planar solar concentrator featuring alignment-free total-internal-reflection (TIR) collectors and an innovative compound tracker. The compound tracker, combining a mechanical single-axis tracker and scrollable prism sheets, can achieve a performance on a par with dual-axis tracking while reducing the cost of the tracking system and increasing its robustness. The alignment-free TIR collectors are assembled on the waveguide without requiring alignment, so the planar concentrator is relatively easily manufactured and markedly increases the feasibility for use in large concentrators. Further, the identical TIR collector is applicable to various-sized waveguide slab without requiring modification, which facilitates flexibility regarding the size of the waveguide slab. In the simulation model, the thickness of the slab was 2 mm, and its maximal length reached 6 m. With an average angular tolerance of ±0.6°, and after considering both the Fresnel loss and the angular spread of the sun, the simulation indicates that the waveguide concentrator of a 1000-mm length provides the optical efficiencies of 62-77% at the irradiance concentrations of 387-688, and the one of a 2000-mm length provides the optical efficiencies of 52-64.5% at the irradiance concentrations of 645-1148. Alternatively, if a 100-mm horizontally staggered waveguide slab is collocated with the alignment-free TIR collectors, the optical efficiency would be greatly improved up to 91.5% at an irradiance concentration of 1098 (C(geo) = 1200X).

  5. Analytical performance of benchtop total reflection X-ray fluorescence instrumentation for multielemental analysis of wine samples

    Science.gov (United States)

    Dalipi, Rogerta; Marguí, Eva; Borgese, Laura; Bilo, Fabjola; Depero, Laura E.

    2016-06-01

    Recent technological improvements have led to a widespread adoption of benchtop total reflection X-ray fluorescence systems (TXRF) for analysis of liquid samples. However, benchtop TXRF systems usually present limited sensitivity compared with high-scale instrumentation which can restrict its application in some fields. The aim of the present work was to evaluate and compare the analytical capabilities of two TXRF systems, equipped with low power Mo and W target X-ray tubes, for multielemental analysis of wine samples. Using the Mo-TXRF system, the detection limits for most elements were one order of magnitude lower than those attained using the W-TXRF system. For the detection of high Z elements like Cd and Ag, however, W-TXRF remains a very good option due to the possibility of K-Lines detection. Accuracy and precision of the obtained results have been evaluated analyzing spiked real wine samples and comparing the TXRF results with those obtained by inductively coupled plasma emission spectroscopy (ICP-OES). In general, good agreement was obtained between ICP-OES and TXRF results for the analysis of both red and white wine samples except for light elements (i.e., K) which TXRF concentrations were underestimated. However, a further achievement of analytical quality of TXRF results can be achieved if wine analysis is performed after dilution of the sample with de-ionized water.

  6. Inorganic pigment study of the San Pedro Gonzalez Telmo Sibyls using total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, Cristina, E-mail: vazquez@cnea.gov.a [Universidad de Buenos Aires, Facultad de Ingenieria, Paseo Colon 850. C1063ACU, Buenos Aires (Argentina); Comision Nacional de Energia Atomica, Gerencia Quimica, Av. Gral Paz 1499, B1650KNA, San Martin (Argentina); Custo, Graciela, E-mail: custo@cnea.gov.a [Comision Nacional de Energia Atomica, Gerencia Quimica, Av. Gral Paz 1499, B1650KNA, San Martin (Argentina); Barrio, Nestor, E-mail: nbarrio@unsam.edu.a [CEIRCAB-TAREA, Universidad Nacional de San Martin (UNSAM), Escuela de Humanidades, Campus Miguelete, 25 de Mayo y Francia, B1650KNA, San Martin (Argentina); Burucua, Jose, E-mail: gburucua@unsam.edu.a [CEIRCAB-TAREA, Universidad Nacional de San Martin (UNSAM), Escuela de Humanidades, Campus Miguelete, 25 de Mayo y Francia, B1650KNA, San Martin (Argentina); Boeykens, Susana [Universidad de Buenos Aires, Facultad de Ingenieria, Paseo Colon 850. C1063ACU, Buenos Aires (Argentina); Marte, Fernando, E-mail: fmarte@unsam.edu.a [CEIRCAB-TAREA, Universidad Nacional de San Martin (UNSAM), Escuela de Humanidades, Campus Miguelete, 25 de Mayo y Francia, B1650KNA, San Martin (Argentina)

    2010-09-15

    This article describes the study carried out on a series of oil paintings on canvas from the eighteenth century that were restored at Centro de Produccion e Investigacion en Restauracion y Conservacion Artistica y Bibliografica - Tarea (CEIRCAB-Tarea), Buenos Aires, Argentina: the San Pedro Gonzalez Telmo Sibyls. Experimental study was undertaken to identify inorganic pigments and the technique used in their confection; and, in this way, try to add information about their local origin. Therefore special emphasis was put to infer technologies used in the manufacturing of these paintings. Elemental analysis was performed by total reflection X-ray fluorescence spectrometry (TXRF) and complemented by optical and polarized light microscopy. Microsampling was carefully done over areas of the paintings which were damaged and where a small additional loss will not be noticed. This investigation has shown that a variety of pigments were used, namely earth pigments (red and yellow ochres), white lead, vermilion, etc., and they were used either pure or in mixtures. This characterization helped conservators in their decisions regarding a better understanding of the deterioration processes. In addition, this research about the material composition allowed the art historians and restorers the possibility to obtain information about where, when or by whom The San Pedro Gonzalez Telmo Sibyls may have been painted.

  7. Intelligent Simultaneous Quantitative Online Analysis of Environmental Trace Heavy Metals with Total-Reflection X-Ray Fluorescence

    Directory of Open Access Journals (Sweden)

    Junjie Ma

    2015-05-01

    Full Text Available Total-reflection X-ray fluorescence (TXRF has achieved remarkable success with the advantages of simultaneous multi-element analysis capability, decreased background noise, no matrix effects, wide dynamic range, ease of operation, and potential of trace analysis. Simultaneous quantitative online analysis of trace heavy metals is urgently required by dynamic environmental monitoring and management, and TXRF has potential in this application domain. However, it calls for an online analysis scheme based on TXRF as well as a robust and rapid quantification method, which have not been well explored yet. Besides, spectral overlapping and background effects may lead to loss of accuracy or even faulty results during practical quantitative TXRF analysis. This paper proposes an intelligent, multi-element quantification method according to the established online TXRF analysis platform. In the intelligent quantification method, collected characteristic curves of all existing elements and a pre-estimated background curve in the whole spectrum scope are used to approximate the measured spectrum. A novel hybrid algorithm, PSO-RBFN-SA, is designed to solve the curve-fitting problem, with offline global optimization and fast online computing. Experimental results verify that simultaneous quantification of trace heavy metals, including Cr, Mn, Fe, Co, Ni, Cu and Zn, is realized on the online TXRF analysis platform, and both high measurement precision and computational efficiency are obtained.

  8. Intelligent simultaneous quantitative online analysis of environmental trace heavy metals with total-reflection X-ray fluorescence.

    Science.gov (United States)

    Ma, Junjie; Wang, Yeyao; Yang, Qi; Liu, Yubing; Shi, Ping

    2015-05-06

    Total-reflection X-ray fluorescence (TXRF) has achieved remarkable success with the advantages of simultaneous multi-element analysis capability, decreased background noise, no matrix effects, wide dynamic range, ease of operation, and potential of trace analysis. Simultaneous quantitative online analysis of trace heavy metals is urgently required by dynamic environmental monitoring and management, and TXRF has potential in this application domain. However, it calls for an online analysis scheme based on TXRF as well as a robust and rapid quantification method, which have not been well explored yet. Besides, spectral overlapping and background effects may lead to loss of accuracy or even faulty results during practical quantitative TXRF analysis. This paper proposes an intelligent, multi-element quantification method according to the established online TXRF analysis platform. In the intelligent quantification method, collected characteristic curves of all existing elements and a pre-estimated background curve in the whole spectrum scope are used to approximate the measured spectrum. A novel hybrid algorithm, PSO-RBFN-SA, is designed to solve the curve-fitting problem, with offline global optimization and fast online computing. Experimental results verify that simultaneous quantification of trace heavy metals, including Cr, Mn, Fe, Co, Ni, Cu and Zn, is realized on the online TXRF analysis platform, and both high measurement precision and computational efficiency are obtained.

  9. Characterization of GLUT4-containing vesicles in 3T3-L1 adipocytes by total internal reflection fluorescence microscopy

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Insulin-responsive GLUT4(glucose transporter 4) translocation plays a major role in regulating glucose uptake in adipose tissue and muscle.Whether or not there is a specialized secretory GSV(GLUT4 storage vesicle) pool,and more importantly how GSVs are translocated to the PM(plasma membrane) under insulin stimulation is still under debate.In the present study,we systematically analyzed the dynamics of a large number of single GLUT4-containing vesicles in 3T3-L1 adipocytes by TIRFM(total internal reflection fluorescence microscopy).We found that GLUT4-containing vesicles can be classified into three groups according to their mobility,namely vertical,stable,and lateral GLUT4-containing vesicles.Among these groups,vertical GLUT4-containing vesicles exclude transferrin receptors and move towards the PM specifically in response to insulin stimulation,while stable and lateral GLUT4-containing vesicles contain transferrin receptors and show no insulin responsiveness.These data demonstrate that vertical GLUT4-containing vesicles correspond to specialized secretory GSVs,which approach the PM directly and bypass the constitutive recycling pathway.

  10. Total reflection X-ray fluorescence applied to the chemical elements analysis of the mate tea infusion (Ilex-paraguariensis)

    International Nuclear Information System (INIS)

    The purpose was to evaluate simultaneously the chemical element concentrations from K to Sr (19≤Z≤38) range in six samples of mate tea (Ilex paraguariensis) infusion, commercially available in Paraguay and South of Brazil. The chemical analysis of this beverage has a great nutritional importance for the native people of these areas, due to their large daily consumption. For the determination of these elements the dry-ashing and total reflection X-rays fluorescence (TXRF) were used. The methodology showed limits of detection among 81 ng.mL-1 for K to 10 ng.mL-1 for Zn. Six infusion samples were prepared in triplicate, and the concentration was 3,8 to 10,2 μg.mL-1 for K, Ca and Mn, 0,21 to 1,07 μg. mL-1 for Fe and Zn and 0.03 to 0,17 μg.mL-1 for Ni, Cu, Br, Rb and Sr. The Mn and Ni concentrations are above the maximum permissible values for drinking water established by World Health Organization and Brazilian legislation (these organisms do not regulate the maximum permissible values for chemical elements in mate tea infusion). (author)

  11. Inorganic pigment study of the San Pedro Gonzalez Telmo Sibyls using total reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    This article describes the study carried out on a series of oil paintings on canvas from the eighteenth century that were restored at Centro de Produccion e Investigacion en Restauracion y Conservacion Artistica y Bibliografica - Tarea (CEIRCAB-Tarea), Buenos Aires, Argentina: the San Pedro Gonzalez Telmo Sibyls. Experimental study was undertaken to identify inorganic pigments and the technique used in their confection; and, in this way, try to add information about their local origin. Therefore special emphasis was put to infer technologies used in the manufacturing of these paintings. Elemental analysis was performed by total reflection X-ray fluorescence spectrometry (TXRF) and complemented by optical and polarized light microscopy. Microsampling was carefully done over areas of the paintings which were damaged and where a small additional loss will not be noticed. This investigation has shown that a variety of pigments were used, namely earth pigments (red and yellow ochres), white lead, vermilion, etc., and they were used either pure or in mixtures. This characterization helped conservators in their decisions regarding a better understanding of the deterioration processes. In addition, this research about the material composition allowed the art historians and restorers the possibility to obtain information about where, when or by whom The San Pedro Gonzalez Telmo Sibyls may have been painted.

  12. Depth profiling using total reflection X-ray fluorescence spectrometry alone and in combination with ion beam sputtering

    Science.gov (United States)

    Schwenke, H.; Knoth, J.; Günther, R.; Wiener, G.; Bormann, R.

    1997-07-01

    The capability of total reflection X-ray fluorescence spectrometry (TXRF) for depth profiling is examined by means of selected examples including organometallic layers, an implantation profile of arsenic in silicon and a layered nickel/cobalt structure. For structures without density differences that are deeper than 20 nm or so, and also for buried layers and for the examination of sharp interfaces, which require the highest resolution, two different combinations of ion beam sputtering with TXRF have been employed. A microsectioning technique was investigated in which samples were etched to a bevel shape and subsequently scanned by TXRF. A depth resolution of 2.5 nm was obtained. Alternatively, the so called "transfer technique" was investigated. This involves surface atoms being sputtered by an ion beam and immediately deposited on a silicon wafer rotated behind a slit which is moved in step with the sputter progress. Subsequently, the wafer is scanned by TXRF. Using this technique, the width of a coherent Ti/Al interface within a layered structure was measured to be 1.4 nm. The depth resolutions of the "microsectioning" and the "transfer" techniques are compared with data from RBS, XPS, SIMS and SNMS.

  13. Determination of platinum group metal catalyst residues in active pharmaceutical ingredients by means of total reflection X-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Marguí, Eva, E-mail: eva.margui@udg.edu [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Queralt, Ignasi, E-mail: iqueralt@ictja.csic.es [Laboratory of X-ray Analytical Applications, Institute of Earth Sciences “Jaume Almera”, CSIC, Solé Sabarís s/n, 08028 Barcelona (Spain); Hidalgo, Manuela, E-mail: manuela.hidalgo@udg.edu [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain)

    2013-08-01

    The control of metal catalyst residues (i.e., platinum group metals (PGMs)) in different stages of the manufacturing processes of the active pharmaceutical ingredients (APIs) and, especially, in the final product is crucial. For API specimens, there are strict guidelines to limit the levels of metal residues based on their individual levels of safety concern. For PGMs the concentration limit has been established at 10 mg/kg in the API. Therefore great effort is currently being devoted to the development of new and simple procedures to control metals in pharmaceuticals. In the present work, an analytical methodology based on benchtop total reflection X-ray fluorescence spectrometry (TXRF) has been developed for the rapid and simple determination of some PGM catalyst impurities (Rh, Pd, Ir and Pt) in different types of API samples. An evaluation of different sample treatments (dissolution and digestion of the solid pharmaceutical samples) has been carried out and the developed methodologies have been validated according to the analytical parameters to be considered and acceptance criteria for PGM determination according to the United States Pharmacopeia (USP). Limits of quantification obtained for PGM metals were in the range of 2–4 mg/kg which are satisfactory according to current legislation. From the obtained results it is shown that the developed TXRF method can be implemented in the pharmaceutical industries to increase productivity of the laboratory; offering an interesting and complementary analytical tool to other atomic spectroscopic methods. - Highlights: • A TXRF method for PGM catalyst residue determination in API samples is presented. • Analysis can be performed using 10 μL of the internal standardized dissolved API. • The method is rapid, simple and suitable according to the USP requirements.

  14. Total reflection X-ray fluorescence analysis of oral fluids of women affected by osteoporosis and osteopenia

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Hector Jorge [Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina)], E-mail: jsan@famaf.unc.edu.ar; Valentinuzzi, Maria Cecilia [Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina); Grenon, Miram [Facultad de Odontologia, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina); Abraham, Jose [Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina)

    2008-12-15

    Osteoporosis is a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures; the early stage of decreased bone density is called osteopenia. More than 200 million people are affected and about 50% of post-menopausic women are expected to develop the disease. Osteoporosis, osteopenia and periodontal disease have in common several risk factors, being hyperthyroidism and smoking habits the most important ones. There is scarce information in the literature about the association between periodontal disease and osteoporosis and/or osteopenia. Some works suggest that osteoporotic women are susceptible to a higher loss of periodontal insertion, alveolar bones, and teeth. Thirty adult post-menopausic women were studied; some of them were healthy (control group) and the rest of them were undergoing some stage of osteoporosis or osteopenia. All the subjects were healthy, non-smokers, not having dental implants, and with communitarian periodontal index higher than 1(CPI > 1). Samples of saliva and gingival crevice fluid were extracted with calibrated micro-capillaries and deposited on Si reflectors. Known amounts of Ga were added to the samples in order to act as internal standard for quantification by the total reflection x-ray fluorescence technique. Experimental concentrations of several elements (P, S, Cl, K, Ca, Cr, Fe, NI, Cu, and Zn) were determined. The concentration of some elements in saliva showed different behavior as compared to gingival crevice fluid. Some critical elements of bone composition, such as Ca and Zn, present very distinguishable behavior. Improvements in the statistics are required for a better assessment of a routine method and to establish some correlation with periodontal disease. TXRF seems to be a promising method to evaluate the evolution of osteoporosis.

  15. Zinc and cadmium accumulation in single zebrafish (Danio rerio) embryos - A total reflection X-ray fluorescence spectrometry application

    Energy Technology Data Exchange (ETDEWEB)

    Mages, Margarete [UFZ - Helmholtz Centre for Environmental Research, Dept. River Ecology Brueckstr. 3a/39114 Magdeburg/Germany (Germany); University of Lueneburg, Institute of Ecology and Environmental Chemistry, Department Environmental Chemistry, Scharnhorststrasse 1/21335 Lueneburg/Germany (Germany)], E-mail: margarete.mages@ufz.de; Bandow, Nicole [UFZ - Helmholtz Centre for Environmental Research, Dept. Effect Directed Analysis, Permoser Strasse 15/ 04318 Leipzig/Germany (Germany); Kuester, Eberhard [UFZ - Helmholtz Centre for Environmental Research, Dept. Bioanalytical Ecotoxicology, Permoser Strasse 15/ 04318 Leipzig/Germany (Germany); Brack, Werner [UFZ - Helmholtz Centre for Environmental Research, Dept. Effect Directed Analysis, Permoser Strasse 15/ 04318 Leipzig/Germany (Germany); Tuempling, Wolf von [UFZ - Helmholtz Centre for Environmental Research, Dept. River Ecology Brueckstr. 3a/39114 Magdeburg/Germany (Germany)

    2008-12-15

    Trace metals such as Cadmium (Cd) and Zinc (Zn) are known to exhibit adverse effects on many aquatic organisms including early life stages of fish. In contact with contaminated sediment, fish eggs and embryos may be exposed to metals via the water phase as well as via direct contact with contaminated particles. This may result in body burdens that are difficult to predict and may vary according to individual micro scale exposure conditions. The highly sensitive total reflection X-ray fluorescence spectrometry (TXRF) may provide a tool to analyse individual embryos for internal contaminant concentrations and thus helps to develop a better understanding of dose-response relationships. To test this hypothesis, embryos of Danio rerio were exposed to Cd and Zn spiked sediment in different treatments applying an ion exchange resin for modification of bioavailable concentrations. The TXRF analysis indicated individual embryos with dramatically enhanced exposure compared to other individuals despite uniform exposure conditions on a macro scale. Ion exchanger reduced embryo Zn concentrations to values close to control value with a comparably low standard deviation. Cadmium concentrations in embryos were in the range of 4000 to 7000 {mu}g/g with a median of 5740 {mu}g/g. A commercial ion exchanger reduced individual body burdens by a factor 50 to 100. Individual peak body burdens of up to 3160 {mu}g/g were accompanied by reduced weight of the fish eggs due to early death i.e. coagulation. The investigation of exposure and effects on an individual-based scale may significantly help to reduce uncertainty and inconsistencies occurring in conventional analysis of pooled fish embryo samples.

  16. Application of CO2 Snow Jet Cleaning in Conjunction with Laboratory Based Total Reflection X-Ray Fluorescence

    Science.gov (United States)

    Schmeling, M.; Burnett, D. S.; Allton, J. H.; Rodriquez, M.; Tripa, C. E.; Veryovkin, I. V.

    2013-01-01

    The Genesis mission was the first mission returning solar material to Earth since the Apollo program [1,2]. Unfortunately the return of the space craft on September 8, 2004 resulted in a crash landing, which shattered the samples into small fragments and exposed them to desert soil and other debris. Thus only small fragments of the original collectors are available, each having different degrees of surface contamination. Thorough surface cleaning is required to allow for subsequent analysis of solar wind material embedded within. An initial cleaning procedure was developed in coordination with Johnson Space Center which focused on removing larger sized particulates and a thin film organic contamination acquired during collection in space [3]. However, many of the samples have additional residues and more rigorous and/or innovative cleaning steps might be necessary. These cleaning steps must affect only the surface to avoid leaching and re-distribution of solar wind material from the bulk of the collectors. To aid in development and identification of the most appropriate cleaning procedures each sample has to be thoroughly inspected before and after each cleaning step. Laboratory based total reflection X-ray fluorescence (TXRF) spectrometry lends itself to this task as it is a non-destructive and surface sensitive analytical method permitting analysis of elements from aluminum onward present at and near the surface of a flat substrate [4]. The suitability of TXRF has been demonstrated for several Genesis solar wind samples before and after various cleaning methods including acid treatment, gas cluster ion beam, and CO2 snow jet [5 - 7]. The latter one is non-invasive and did show some promise on one sample [5]. To investigate the feasibility of CO2 snow jet cleaning further, several flown Genesis samples were selected to be characterized before and after CO2 snow application with sample 61052 being discussed below.

  17. Determination of platinum group metal catalyst residues in active pharmaceutical ingredients by means of total reflection X-ray spectrometry

    International Nuclear Information System (INIS)

    The control of metal catalyst residues (i.e., platinum group metals (PGMs)) in different stages of the manufacturing processes of the active pharmaceutical ingredients (APIs) and, especially, in the final product is crucial. For API specimens, there are strict guidelines to limit the levels of metal residues based on their individual levels of safety concern. For PGMs the concentration limit has been established at 10 mg/kg in the API. Therefore great effort is currently being devoted to the development of new and simple procedures to control metals in pharmaceuticals. In the present work, an analytical methodology based on benchtop total reflection X-ray fluorescence spectrometry (TXRF) has been developed for the rapid and simple determination of some PGM catalyst impurities (Rh, Pd, Ir and Pt) in different types of API samples. An evaluation of different sample treatments (dissolution and digestion of the solid pharmaceutical samples) has been carried out and the developed methodologies have been validated according to the analytical parameters to be considered and acceptance criteria for PGM determination according to the United States Pharmacopeia (USP). Limits of quantification obtained for PGM metals were in the range of 2–4 mg/kg which are satisfactory according to current legislation. From the obtained results it is shown that the developed TXRF method can be implemented in the pharmaceutical industries to increase productivity of the laboratory; offering an interesting and complementary analytical tool to other atomic spectroscopic methods. - Highlights: • A TXRF method for PGM catalyst residue determination in API samples is presented. • Analysis can be performed using 10 μL of the internal standardized dissolved API. • The method is rapid, simple and suitable according to the USP requirements

  18. Total reflection X-ray fluorescence analysis of oral fluids of women affected by osteoporosis and osteopenia

    Science.gov (United States)

    Sánchez, Héctor Jorge; Valentinuzzi, María Cecilia; Grenón, Miram; Abraham, José

    2008-12-01

    Osteoporosis is a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures; the early stage of decreased bone density is called osteopenia. More than 200 million people are affected and about 50% of post-menopausic women are expected to develop the disease. Osteoporosis, osteopenia and periodontal disease have in common several risk factors, being hyperthyroidism and smoking habits the most important ones. There is scarce information in the literature about the association between periodontal disease and osteoporosis and/or osteopenia. Some works suggest that osteoporotic women are susceptible to a higher loss of periodontal insertion, alveolar bones, and teeth. Thirty adult post-menopausic women were studied; some of them were healthy (control group) and the rest of them were undergoing some stage of osteoporosis or osteopenia. All the subjects were healthy, non-smokers, not having dental implants, and with communitarian periodontal index higher than 1(CPI > 1). Samples of saliva and gingival crevice fluid were extracted with calibrated micro-capillaries and deposited on Si reflectors. Known amounts of Ga were added to the samples in order to act as internal standard for quantification by the total reflection x-ray fluorescence technique. Experimental concentrations of several elements (P, S, Cl, K, Ca, Cr, Fe, NI, Cu, and Zn) were determined. The concentration of some elements in saliva showed different behavior as compared to gingival crevice fluid. Some critical elements of bone composition, such as Ca and Zn, present very distinguishable behavior. Improvements in the statistics are required for a better assessment of a routine method and to establish some correlation with periodontal disease. TXRF seems to be a promising method to evaluate the evolution of osteoporosis.

  19. On revealing the vertical structure of nanoparticle films with elemental resolution: A total external reflection X-ray standing waves study

    Energy Technology Data Exchange (ETDEWEB)

    Zargham, Ardalan, E-mail: zargham@ifp.uni-bremen.d [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany); Schmidt, Thomas; Flege, Jan Ingo; Sauerbrey, Marc; Hildebrand, Radowan [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany); Roehe, Sarah; Baeumer, Marcus [Applied and Physical Chemistry, University of Bremen, Leobener Str. 2, 28359, Bremen (Germany); Falta, Jens [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany)

    2010-02-15

    We present a promising combination of methods to precisely determine the morphology of nanostructures, drawing on the example of monodisperse CoPt{sub 3} nanoparticle films deposited by spin coating and dip coating techniques on functionalized Au substrates. Ex-situ X-ray standing waves in total external reflection combined with X-ray reflectivity measurements were employed to determine element-specific atomic-density distributions in vertical direction.

  20. Impulsive solar X-ray bursts. 4: Polarization, directivity and spectrum of the reflected and total bremsstrahlung radiation from a beam of electrons directed toward the photosphere

    Science.gov (United States)

    Langer, S. H.; Petrosian, V.

    1976-01-01

    A Monte Carlo method is described for evaluation of the spectrum, directivity and polarization of X-rays diffusely reflected from stellar photospheres. the accuracy of the technique is evaluated through comparison with analytic results. Using the characteristics of the incident X-rays of the model for solar X-ray flares, the spectrum, directivity and polarization of the reflected and the total X-ray fluxes are evaluated. The results are compared with observations.

  1. Total reflection x-ray fluorescence (TXRF) - a tool to obtain information about different air masses and air pollution

    International Nuclear Information System (INIS)

    Aerosols are solid particles dissolved in the atmosphere and have strong influence in the earth climate. Their solid surfaces are the only atmospheric medium for condensation of water leading to cloud formation and ultimately to precipitation. Besides their role in cloud formation, the elemental composition of aerosols reveals useful information about air masses and their transport patterns as well as air pollution. The elemental composition can be considered like a fingerprint of an air mass telling the story about its origin and fate. The presence of Al, Ti and Fe for instance indicates a source located in a highly exposed soil or often desert region, whereas Ni, V and Pb can be traced back to anthropogenic activities like fuel combustion or industrial processes. Other important source regions are the oceans, which emit the main aerosol constituents Na, Cl, and S. The concentrations of these elements in the atmosphere are extremely low and long sampling times are necessary to gain reliable results with most of the common analysis techniques. In contrast to this total reflection x-ray fluorescence (TXRF), as a technique capable to cope with tiny sample amounts, offers the unique possibility to reduce collection times to a minimum of minutes to hours. Such short sampling times in turn render it possible to monitor different air masses either passing through a ground based station or -in the ideal case- flown into by a small research aircraft. Different aerosol samples were taken by aircraft during the second aerosol characterization experiment (ACE-2) with sampling times ranging from 15 minutes up to one hour. These filter samples were analyzed by TXRF for trace elements subsequently. Together with background information about back trajectories and size distribution covering the time of sampling the presence of different air masses could be detected. In another project, short-term samples in the Chicago/Lake Michigan area are collected to study the air mass

  2. Experimental infection of commercial layers with wild or attenuated Salmonella Gallinarum mutant strains: anatomic pathology, total blood cell count and serum protein levels

    Directory of Open Access Journals (Sweden)

    KO Garcia

    2013-06-01

    Full Text Available The aim of the present study was to comparatively evaluate hemogram, blood serum components and anatomopathologic alterations in commercial layers experimentally challenged with an attenuated vaccine candidate strain (SG∆cobS∆cbiA and other two pathogenic strains (SGDcobS and SGNalr of Gallinarum (SG. In total, 280 commercial layers were randomly divided into 4 groups (G1, G2, G3 and G4. At five days of age, birds from groups G1 received approximately 107 colony forming units (CFU of SGDcobS; meanwhile birds from group G2 and G3 received the same dose of SGNalr and SG∆cobS∆cbiA, respectively. Birds from G4 were not infected. At 24 hours before (DBI and 24 hours after (1 DAI, and three (3 DAI, five (5 DAI, seven (7 DAI ten (10 DAI, and fifteen (15 DAI days after the infection, 10 birds of each group were humanely killed and blood samples collected to hematological and serum tests. Samples of liver, spleen, thymus, bursa of Fabricius, kidney and heart were also collected for the histological examination. Birds inoculated with SGDcobS and SGNalr showed similar alterations in hemogram, blood serum components and anatomopathologic exams. On the other hand, the exams of birds inoculated with SG∆cobS∆cbiA strain were similar to those of the uninfected birds. However, changes could be noticed in levels of uric acid and cholesterol during the course of the infection of birds from G3. Decrease in levels of light IgG 3 DAI was also observed in birds from this group. Pyknosis in kidney cells was a microscopic alteration found in birds from G3. Further studies must be done to verify if these alterations will not interfere in the performance of the vaccinate birds with SG∆cobS∆cbiA strain.

  3. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions.

    Science.gov (United States)

    Jeong, Young-Il; Kim, Seung Hyun; Ju, Jung Won; Cho, Shin Hyeong; Lee, Won Ja; Park, Jin Wook; Park, Yeong-Min; Lee, Sang Eun

    2011-04-22

    Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naïve T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical relationship between the allergic immune response and helminth infection. PMID:21440530

  4. Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy; Determinacion de plomo en esmaltado de barro por Fluorescencia de rayos X en reflexion total y Microscopia Electronica de Barrido

    Energy Technology Data Exchange (ETDEWEB)

    Zarazua O, G.; Carapia M, L. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Estado de Mexico (Mexico)

    2000-07-01

    This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

  5. Simple and rapid quantification of total carotenoids in lyophilized apricots (prunus armeniaca L.) by means of reflectance colorimetry and photoacoustic spectrometry spectroscopy

    NARCIS (Netherlands)

    Doka, O.; Ficzek, G.; Luterotti, S.; Bicanic, D.D.; Spruijt, R.B.; Buijnsters, J.; Vegvari, G.

    2013-01-01

    Photoacoustic spectroscopy (PAS) and reflectance colorimetry are suggested as new tools for the analysis of total carotenoids in lyophilized apricot powders. The data obtained by these two techniques from seven apricot cultivars were compared to those acquired by spectrophotometry and high-performan

  6. Observation of surface reduction of NiO to Ni by surface-sensitive total reflection X-ray spectroscopy using Kramers-Kronig relations

    Science.gov (United States)

    Abe, Hitoshi; Nakayama, Takeshi; Niwa, Yasuhiro; Nitani, Hiroaki; Kondoh, Hiroshi; Nomura, Masaharu

    2016-06-01

    We have developed a promising surface-sensitive X-ray absorption fine structure (XAFS) measurement method. This method is based on total reflection detection and Kramers-Kronig relations, and has been named the KK-XAFS method. Total reflection spectra are transformed via Kramers-Kronig relations to obtain XAFS spectra. KK-XAFS experiments give us surface-sensitive structural parameters, while usual EXAFS analyses yield bulk structural parameters. The total reflection spectra themselves are useful for observing and discussing time evolutions of chemical reactions at surfaces by quick scanning measurements. Chemical species are analyzed to estimate their fractions during reactions. The whole method would be named total reflection X-ray spectroscopy (TREXS). A reduction of the NiO layer at the surface of Ni (30 nm)/Si was observed in a laboratory-built TREXS in situ cell. The method would be applicable to observe chemical reactions starting at surfaces and to study their kinetics and mechanisms.

  7. Association Mapping of Total Carotenoids in Diverse Soybean Genotypes Based on Leaf Extracts and High-Throughput Canopy Spectral Reflectance Measurements

    Science.gov (United States)

    Dhanapal, Arun Prabhu; Ray, Jeffery D.; Singh, Shardendu K.; Hoyos-Villegas, Valerio; Smith, James R.; Purcell, Larry C.; King, C. Andy; Fritschi, Felix B.

    2015-01-01

    Carotenoids are organic pigments that are produced predominantly by photosynthetic organisms and provide antioxidant activity to a wide variety of plants, animals, bacteria, and fungi. The carotenoid biosynthetic pathway is highly conserved in plants and occurs mostly in chromoplasts and chloroplasts. Leaf carotenoids play important photoprotective roles and targeted selection for leaf carotenoids may offer avenues to improve abiotic stress tolerance. A collection of 332 soybean [Glycine max (L.) Merr.] genotypes was grown in two years and total leaf carotenoid content was determined using three different methods. The first method was based on extraction and spectrophotometric determination of carotenoid content (eCaro) in leaf tissue, whereas the other two methods were derived from high-throughput canopy spectral reflectance measurements using wavelet transformed reflectance spectra (tCaro) and a spectral reflectance index (iCaro). An association mapping approach was employed using 31,253 single nucleotide polymorphisms (SNPs) to identify SNPs associated with total carotenoid content using a mixed linear model based on data from two growing seasons. A total of 28 SNPs showed a significant association with total carotenoid content in at least one of the three approaches. These 28 SNPs likely tagged 14 putative loci for carotenoid content. Six putative loci were identified using eCaro, five loci with tCaro, and nine loci with iCaro. Three of these putative loci were detected by all three carotenoid determination methods. All but four putative loci were located near a known carotenoid-related gene. These results showed that carotenoid markers can be identified in soybean using extract-based as well as by high-throughput canopy spectral reflectance-based approaches, demonstrating the utility of field-based canopy spectral reflectance phenotypes for association mapping. PMID:26368323

  8. Novel Folding Large-Scale Optical Switch Matrix with Total Internal Reflection Mirrors on Silicon-on-Insulator by Anisotropy Chemical Etching

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Wei; YU Jin-Zhong; CHEN Shao-Wu

    2005-01-01

    A compact optical switch matrix was designed, in which light circuits were folded by total internal reflective (TIR) mirrors. Two key elements, 2 × 2 switch and TIR mirror, have been fabricated on silicon-on-insulator wafer by anisotropy chemical etching. The 2 × 2 switch showed very low power consumption of 140mW and avery high speed of 8 ± 1 μs. An improved design for the TIR mirror was developed, and the fabricated mirror with smooth and vertical reflective facet showed low excess loss of 0.7 ± 0.3 dB at 1.55μm.

  9. Impulsive solar X-ray bursts. III - Polarization, directivity, and spectrum of the reflected and total bremsstrahlung radiation from a beam of electrons directed toward the photosphere

    Science.gov (United States)

    Langer, S. H.; Petrosian, V.

    1977-01-01

    The paper presents the spectrum, directivity, and state of polarization of the bremsstrahlung radiation expected from a beam of high-energy electrons spiraling along radial magnetic field lines toward the photosphere. A Monte Carlo method is then described for evaluation of the spectrum, directivity, and polarization of X-rays diffusely reflected from stellar photospheres. The accuracy of the technique is evaluated through comparison with analytic results. The calculated characteristics of the incident X-rays are used to evaluate the spectrum, directivity, and polarization of the reflected and total X-ray fluxes. The results are compared with observations.

  10. Optical interrupter based in the internal total reflection of spatial solitons at nonlinear saturable interfaces; Interruptores opticos basados en reflexion interna total de solitones espaciales en interfaces no lineales saturables

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado-Mendez, E.; Torres-Cisneros, M.; Gutierrez-Hernandez, D. A.; Andrade-Lucio, J. A.; Rojas-Lagunas, R.; Pedraza-Ortega, J. C.; Torres Cisneros, G. E. [Universidad de Guanajuato, Guanajuato (Mexico); Sanchez Mondragon, J. J. [Universidad Autonoma del Estado de Morelos, Morelos (Mexico); Flores-Alvarado, G. [Preparatoria por Cooperacion Domingo Arenas, Tlaxcala (Mexico)

    2001-06-01

    We study the reflection of one-dimensional spatial soliton at the nonlinear interface between a saturable type medium and linear medium. Our study makes emphasis on determining the physical conditions under which the beam reflected by the interface is still a spatial soliton. Depended the incidence angle we find three critical regions for spatial solitons in the interface. We observed nonlinear Goos- Haechen shift is determined if reflection angle are conserved. Finally, we present preliminary experimental results in SBN61:Ce of the total internal reflection of one dimensional beam. [Spanish] Estudiamos la reflexion de un soliton espacial unidimensional en una interfase formada por un medio no lineal saturable y un medio lineal. Nuestros estudios hacen enfasis en determinar las condiciones fisicas bajo las cuales el haz reflejado por la interfase no lineal sigue siendo soliton. Encontramos tres regiones criticas para un soliton especial en la interfase, dependiendo del valor que tome el angulo de incidencia. Asi mismo observamos corrimiento Goos-Haechen no lineal que es determinante para la conservacion del angulo de reflexion. Finalmente, presentamos resultados preliminares experimentales en SBN61:Ce de la reflexion interna total de un haz unidimensional.

  11. Simple method of determination of copper, mercury and lead in potable water with preliminary pre-concentration by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Hołyńska, B.; Ostachowicz, B.; Wȩgrzynek, D.

    1996-06-01

    Total reflection X-ray fluorescence spectrometry and chemical pre-concentration procedures have been applied for the analysis of trace concentrations of copper, mercury, and lead in drinking water samples. A simple total reflection module has been used in X-ray measurements. The elements under investigation were pre-concentrated by complexation using a mixture of carbamates followed by solvent extraction with methyl isobutyl ketone. The preconcentration procedure was tested with the use of twice-distilled water samples and samples of mineral and tap water spiked with known additions of copper, mercury, and lead. The obtained recovery and precision values are presented. The minimum detection limits for the determination of these elements in mineral and tap water samples were found to be 40 ng l -1, 60 ng l -1, and 60 ng l -1, respectively.

  12. Direct analysis of blood serum by total reflection X-ray fluorescence spectrometry and application of an artificial neural network approach for cancer diagnosis*1

    Science.gov (United States)

    Hernández-Caraballo, Edwin A.; Marcó-Parra, Lué M.

    2003-12-01

    Iron, copper, zinc and selenium were determined directly in serum samples from healthy individuals ( n=33) and cancer patients ( n=27) by total reflection X-ray fluorescence spectrometry using the Compton peak as internal standard [L.M. Marcó P. et al., Spectrochim. Acta Part B 54 (1999) 1469-1480]. The standardized concentrations of these elements were used as input data for two-layer artificial neural networks trained with the generalized delta rule in order to classify such individuals according to their health status. Various artificial neural networks, comprising a linear function in the input layer, a hyperbolic tangent function in the hidden layer and a sigmoid function in the output layer, were evaluated for such a purpose. Of the networks studied, the (4:4:1) gave the highest estimation (98%) and prediction rates (94%). The latter demonstrates the potential of the total reflection X-ray fluorescence spectrometry/artificial neural network approach in clinical chemistry.

  13. Monitoring of an esterification reaction by on-line direct liquid sampling mass spectrometry and in-line mid infrared spectrometry with an attenuated total reflectance probe

    Energy Technology Data Exchange (ETDEWEB)

    Owen, Andrew W.; McAulay, Edith A.J. [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Nordon, Alison, E-mail: alison.nordon@strath.ac.uk [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Littlejohn, David, E-mail: d.littlejohn@strath.ac.uk [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Lynch, Thomas P. [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Lancaster, J. Steven [Hull Research and Technology Centre, BP Chemicals, Hull, HU12 8DS (United Kingdom); Wright, Robert G. [Thermo Fisher Scientific, Winsford, Cheshire, CW7 3GA (United Kingdom)

    2014-11-07

    Highlights: • High efficiency thermal vaporiser designed and used for on-line reaction monitoring. • Concentration profiles of all reactants and products obtained from mass spectra. • By-product formed from the presence of an impurity detected by MS but not MIR. • Mass spectrometry can detect trace and bulk components unlike molecular spectrometry. - Abstract: A specially designed thermal vaporiser was used with a process mass spectrometer designed for gas analysis to monitor the esterification of butan-1-ol and acetic anhydride. The reaction was conducted at two scales: in a 150 mL flask and a 1 L jacketed batch reactor, with liquid delivery flow rates to the vaporiser of 0.1 and 1.0 mL min{sup −1}, respectively. Mass spectrometry measurements were made at selected ion masses, and classical least squares multivariate linear regression was used to produce concentration profiles for the reactants, products and catalyst. The extent of reaction was obtained from the butyl acetate profile and found to be 83% and 76% at 40 °C and 20 °C, respectively, at the 1 L scale. Reactions in the 1 L reactor were also monitored by in-line mid-infrared (MIR) spectrometry; off-line gas chromatography (GC) was used as a reference technique when building partial least squares (PLS) multivariate calibration models for prediction of butyl acetate concentrations from the MIR spectra. In validation experiments, good agreement was achieved between the concentration of butyl acetate obtained from in-line MIR spectra and off-line GC. In the initial few minutes of the reaction the profiles for butyl acetate derived from on-line direct liquid sampling mass spectrometry (DLSMS) differed from those of in-line MIR spectrometry owing to the 2 min transfer time between the reactor and mass spectrometer. As the reaction proceeded, however, the difference between the concentration profiles became less noticeable. DLSMS had advantages over in-line MIR spectrometry as it was easier to generate concentration profiles for all the components in the reaction. Also, it was possible to detect the presence of a simulated impurity of ethanol (at levels of 2.6 and 9.1% mol/mol) in butan-1-ol, and the resulting production of ethyl acetate, by DLSMS, but not by in-line MIR spectrometry.

  14. Rapid discrimination and characterization of vanilla bean extracts by attenuated total reflection infrared spectroscopy and selected ion flow tube mass spectrometry.

    Science.gov (United States)

    Sharp, Michael D; Kocaoglu-Vurma, Nurdan A; Langford, Vaughan; Rodriguez-Saona, Luis E; Harper, W James

    2012-03-01

    Vanilla beans have been shown to contain over 200 compounds, which can vary in concentration depending on the region where the beans are harvested. Several compounds including vanillin, p-hydroxybenzaldehyde, guaiacol, and anise alcohol have been found to be important for the aroma profile of vanilla. Our objective was to evaluate the performance of selected ion flow tube mass spectrometry (SIFT-MS) and Fourier-transform infrared (FTIR) spectroscopy for rapid discrimination and characterization of vanilla bean extracts. Vanilla extracts were obtained from different countries including Uganda, Indonesia, Papua New Guinea, Madagascar, and India. Multivariate data analysis (soft independent modeling of class analogy, SIMCA) was utilized to determine the clustering patterns between samples. Both methods provided differentiation between samples for all vanilla bean extracts. FTIR differentiated on the basis of functional groups, whereas the SIFT-MS method provided more specific information about the chemical basis of the differentiation. SIMCA's discriminating power showed that the most important compounds responsible for the differentiation between samples by SIFT-MS were vanillin, anise alcohol, 4-methylguaiacol, p-hydroxybenzaldehyde/trimethylpyrazine, p-cresol/anisole, guaiacol, isovaleric acid, and acetic acid. ATR-IR spectroscopy analysis showed that the classification of samples was related to major bands at 1523, 1573, 1516, 1292, 1774, 1670, 1608, and 1431 cm(-1) , associated with vanillin and vanillin derivatives.

  15. Characterization of attenuated total reflection infrared spectral intensity variations of immature and mature cotton fibers by two-dimensional correlation analysis

    Science.gov (United States)

    Two-dimensional (2D) correlation analysis was applied to characterize the ATR spectral intensity fluctuations of immature and mature cotton fibers. Prior to 2D analysis, the spectra were leveled to zero at the peak intensity of 1800 cm-1 and then were normalized at the peak intensity of 660 cm-1 to ...

  16. Rapid Identification of Thermoplastic Elastomer of Polyvinyl Chloride by Attenuated Total Reflection Infrared Spectrography%FTIR-ATR法快速鉴定T-PVC

    Institute of Scientific and Technical Information of China (English)

    俞雄飞; 张伟

    2005-01-01

    以环己酮为溶剂,无水乙醇为沉淀剂,溶解-沉淀法消除增塑剂的干扰,以锗晶体为反射晶体,衰减全反射红外光谱法定性测定聚氯乙烯成分.该法简单、快速、安全、准确.

  17. Real-time feedback control using online attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy for continuous flow optimization and process knowledge.

    Science.gov (United States)

    Skilton, Ryan A; Parrott, Andrew J; George, Michael W; Poliakoff, Martyn; Bourne, Richard A

    2013-10-01

    The use of automated continuous flow reactors is described, with real-time online Fourier transform infrared spectroscopy (FT-IR) analysis to enable rapid optimization of reaction yield using a self-optimizing feedback algorithm. This technique has been applied to the solvent-free methylation of 1-pentanol with dimethyl carbonate using a γ-alumina catalyst. Calibration of the FT-IR signal was performed using gas chromatography to enable quantification of yield over a wide variety of flow rates and temperatures. The use of FT-IR as a real-time analytical technique resulted in an order of magnitude reduction in the time and materials required compared to previous studies. This permitted a wide exploration of the parameter space to provide process understanding and validation of the optimization algorithms. PMID:24067568

  18. Monitoring of an esterification reaction by on-line direct liquid sampling mass spectrometry and in-line mid infrared spectrometry with an attenuated total reflectance probe

    International Nuclear Information System (INIS)

    Highlights: • High efficiency thermal vaporiser designed and used for on-line reaction monitoring. • Concentration profiles of all reactants and products obtained from mass spectra. • By-product formed from the presence of an impurity detected by MS but not MIR. • Mass spectrometry can detect trace and bulk components unlike molecular spectrometry. - Abstract: A specially designed thermal vaporiser was used with a process mass spectrometer designed for gas analysis to monitor the esterification of butan-1-ol and acetic anhydride. The reaction was conducted at two scales: in a 150 mL flask and a 1 L jacketed batch reactor, with liquid delivery flow rates to the vaporiser of 0.1 and 1.0 mL min−1, respectively. Mass spectrometry measurements were made at selected ion masses, and classical least squares multivariate linear regression was used to produce concentration profiles for the reactants, products and catalyst. The extent of reaction was obtained from the butyl acetate profile and found to be 83% and 76% at 40 °C and 20 °C, respectively, at the 1 L scale. Reactions in the 1 L reactor were also monitored by in-line mid-infrared (MIR) spectrometry; off-line gas chromatography (GC) was used as a reference technique when building partial least squares (PLS) multivariate calibration models for prediction of butyl acetate concentrations from the MIR spectra. In validation experiments, good agreement was achieved between the concentration of butyl acetate obtained from in-line MIR spectra and off-line GC. In the initial few minutes of the reaction the profiles for butyl acetate derived from on-line direct liquid sampling mass spectrometry (DLSMS) differed from those of in-line MIR spectrometry owing to the 2 min transfer time between the reactor and mass spectrometer. As the reaction proceeded, however, the difference between the concentration profiles became less noticeable. DLSMS had advantages over in-line MIR spectrometry as it was easier to generate concentration profiles for all the components in the reaction. Also, it was possible to detect the presence of a simulated impurity of ethanol (at levels of 2.6 and 9.1% mol/mol) in butan-1-ol, and the resulting production of ethyl acetate, by DLSMS, but not by in-line MIR spectrometry

  19. Secondary structure of the intact H+,K+ -ATPase and of its membrane-embedded region. An attenuated total reflection infrared spectroscopy, circular dichroism and Raman spectroscopy study

    NARCIS (Netherlands)

    Raussens, V.; Jongh, H. de; Pézolet, M.; Ruysschaert, J.-M.; Goormaghtigh, E.

    1998-01-01

    Models of P-type ATPase predict that membrane-embedded fragments represent about 20% of the protein and adopt an all-α-helical structure. While this prediction was confirmed for the Ca2+ -ATPase [Corbalan-Garcia, S., Teruel, J., Villalain, J. and Gomez-Fernandez, J. (1994) Biochemistry 33, 8247-8254

  20. Multi-transmitting formula for attenuating waves

    Institute of Scientific and Technical Information of China (English)

    陈少林; 廖振鹏

    2003-01-01

    The MTF is extended to case of attenuating incident wave by introducing an attenuation coefficient. The reflection coefficients of this modified MTF and MTF areevaluated and compared when an attenuating wave impinges on the boundary, and the results demonstrate that MTF can be used to absorb slightly attenuating wavesand the modified MTF is more capable of absorbing heavily attenuating waves than MTF. The accuracy of modified MTF is also tested by numerical examples of fluid saturated porous media.

  1. Estimation of direct, diffuse, and total FPARs from Landsat surface reflectance data and ground-based estimates over six FLUXNET sites

    Science.gov (United States)

    Li, Wenjuan; Fang, Hongliang

    2015-04-01

    The fraction of photosynthetically active radiation (PAR) absorbed by green elements (FPAR) is an essential climate variable (ECV) in quantifying canopy absorbed PAR (APAR) and gross and net primary production. It has been demonstrated that FPAR is larger under totally diffuse than clear sky conditions because all canopy parts can absorb lights effectively under diffuse conditions. The direct and diffuse FPARs are defined, therefore, as the FPAR values obtained under clear (most sunny) and overcast (most cloudy) conditions, respectively, and FPAR represents the summed canopy absorption efficiency for both direct and diffuse PAR. Satellite FPAR products, such as MODIS, GEOV1, MERIS, and JRC-TIP, have been generated at different temporal and spatial resolutions. Except for JRC-TIP which generates direct and diffuse FPARs separately, all the other products typically correspond to the instantaneous black-sky FPAR under direct illumination only. However, even under fully clear sky conditions, the proportion of diffuse PAR over the surface cannot be ignored. Otherwise, FPAR will be underestimated, especially for small leaf area index (LAI) region. To address this, the present study developed a new approach to estimate direct, diffuse, and total FPARs, separately, from Landsat 30m surface reflectance data. Field-measured direct and diffuse FPARs were first derived for crops, deciduous broadleaf forests, and evergreen needleleaf forests at six FLUXNET sites. Then, a coupled soil-leaf-canopy (SLC) radiative transfer model was used to simulate surface reflectance under direct and diffuse illumination conditions, respectively. Direct, diffuse, and total FPARs were estimated by comparing Landsat-5 Thematic Mapper (TM) data and simulated surface reflectances using a lookup table approach. The differences between the Landsat-estimated and the field-measured FPARs are less than 0.05 (10%). The diffuse FPAR is higher than the direct FPAR by up to 19.38%, whereas the total FPAR is

  2. Numerical simulation by TVD schemes of complex shock reflections from airfoils at high angle of attack. [Total Variation Diminishing

    Science.gov (United States)

    Moon, Young J.; Yee, H. C.

    1987-01-01

    The shock-capturing capability of total variation diminishing (TVD) schemes is demonstrated for a more realistic complex shock-diffraction problem for which the experimental data are available. Second-order explicit upwind and symmetric TVD schemes are used to solve the time-dependent Euler equations of gas dynamics for the interaction of a blast wave with an airfoil at high angle-of-attack. The test cases considered are a time-dependent moving curved-shock wave and a contant moving planar-shock wave impinging at an angle-of-attack 30 deg on a NACA 0018 airfoil. Good agreement is obtained between isopycnic contours computed by the TVD schemes and those from experimental interferograms. No drastic difference in flow-field structure is found between the curved- and planar-shock wave cases, except for a difference in density level near the lower surface of the airfoil. Computation for cases with higher shock Mach numbers is also possible. Numerical experiments show that the symmetric TVD scheme is less sensitive to the boundary conditions treatment than the upwind scheme.

  3. Slow neutron total cross-section, transmission and reflection calculation for poly- and mono-NaCl and PbF2 crystals

    Science.gov (United States)

    Mansy, Muhammad S.; Adib, M.; Habib, N.; Bashter, I. I.; Morcos, H. N.; El-Mesiry, M. S.

    2016-10-01

    A detailed study about the calculation of total neutron cross-section, transmission and reflection from crystalline materials was performed. The developed computer code is approved to be sufficient for the required calculations, also an excellent agreement has been shown when comparing the code results with the other calculated and measured values. The optimal monochromator and filter parameters were discussed in terms of crystal orientation, mosaic spread, and thickness. Calculations show that 30 cm thick of PbF2 poly-crystal is an excellent cold neutron filter producing neutron wavelengths longer than 0.66 nm needed for the investigation of magnetic structure experiments. While mono-crystal filter PbF2 cut along its (1 1 1), having mosaic spread (η = 0.5°) and thickness 10 cm can only transmit thermal neutrons of the desired wavelengths and suppress epithermal and γ-rays forming unwanted background, when it is cooled to liquid nitrogen temperature. NaCl (2 0 0) and PbF2 (1 1 1) monochromator crystals having mosaic spread (η = 0.5°) and thickness 10 mm shows high neutron reflectivity for neutron wavelengths (λ = 0.114 nm and λ = 0.43 nm) when they used as a thermal and cold neutron monochromators respectively with very low contamination from higher order reflections.

  4. Si-prism-array coupled terahertz-wave parametric oscillator with pump light totally reflected at the terahertz-wave exit surface.

    Science.gov (United States)

    Zhang, Ruiliang; Qu, Yanchen; Zhao, Weijiang; Liu, Chuang; Chen, Zhenlei

    2016-09-01

    A Si-prism-array coupled terahertz (THz)-wave parametric oscillator with the pump totally reflected at the THz-wave exit surface (PR-Si-TPO) is demonstrated by manufacturing an 800 nm air gap between the crystal and the Si-prism array. Influence on the total reflection of the pump from the Si prisms is eliminated and efficient coupling of the THz wave is ensured by using this air gap. When the THz-wave frequency varies from 1.8 to 2.3 THz, compared with a Si-prism-array coupled TPO (Si-TPO) with the pump transmitting through the crystal directly, the THz-wave output energy is enhanced by 20-50 times, and the oscillating threshold is reduced by 10%-35%. Furthermore, the high end of the THz-wave frequency tuning range of the PR-Si-TPO is expanded to 3.66 THz compared with 2.5 THz for the Si-TPO.

  5. Attenuation of the Disruptive Effect induced by the Insecticide Fenvalerate on Total Monoamine Content and Testosterone Level in Adult Male Albino Rats Using Salvia aegyptiaca Extract

    International Nuclear Information System (INIS)

    Administration of fenvalerate (90 mg/kg) to rats resulted in a significant decrease in dopamine (OA) content in most of brain areas under investigation. Its content in pons + medulla oblongata was the most affected recording - 62.98 %, on day 7, compared to control. Furthermore, norepinephrine (NE) content gradually decreased in different brain areas showing its maximal decrease in cerebellum with percentage change -64.89% on day 7. Serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) showed maximal significant decrease, in the cortex with percentage differences -78.33 and -72.61%, respectively. Similarly, fen valerate resulted in a gradual decrease in serum testosterone level recording its maximal effect (-46. 58 %) at the end of the experimental period. On the other hand, administration of Salvia aegyptiaca (2 g/kg) caused a significant increase in monoamine contents (DA, NE, 5-HT and 5- HlAA) in most of the brain areas under investigation, throughout the experimental period. Moreover, Salvia extract administration resulted in a significant elevation in serum testosterone level, one day after administration, recording its maximal effect (55.75%) on day 7. Animals that received the combined treatment (Salvia extract one hour after fen valerate administration) showed that monoamine contents in most of the brain areas were more or less near to the control values. Furthermore, no significant change was noticed in serum testosterone level throughout the experiment in the combined treatment. From the present study, it can be concluded that Salvia aegyptiaca extract seems to be potentially promising for attenuating the disruption that occurred in monoamine and testosterone levels. This could highly recommend Salvia aegyptiaca to be a potential herb for further studies in the future for extracting compounds of medical use

  6. A sensitive method for determining total vanadium in water samples using colorimetric-solid-phase extraction-fiber optic reflectance spectroscopy

    International Nuclear Information System (INIS)

    A selective colorimetric-solid-phase extraction (C-SPE) method for the determination of total vanadium in water samples was developed. This method introduced a new variation of C-SPE. The colour reaction is based on the reaction of vanadium(V) ternary complex formed with 1-(2-Pyridylazo)-2-naphtol (PAN) in the presence hydrogen peroxide (H2O2). In this technique, the target analytes in samples are extracted onto solid matrix loaded with a colorimetric reagent and then quantified directly on the adsorbent surface by using a miniature fiber optic reflectance spectrometer. The measurements were carried out at a wavelength of 589.4 nm since it yielded the largest divergence different in reflectance spectra before and after reaction with the vanadium. The overall time required for the C-SPE procedure was ∼20 min. The amount of concentrated V is then determined in a few seconds by using miniature reflectance spectrometer. At the optimal conditions, a calibration curve was constructed, revealing a linear range of 0.05-0.52 mg L-1 and a detection limit as low as 0.01 mg L-1 while the RSD lower than 2.8%. In order to verify the accuracy of the method, a certified reference water samples (TMDA) were analysed and the results obtained were in good agreement with the certified values. The proposed method was applied to the determination of vanadium in tap water, seawater samples with a recovery for the spiked samples in the range of 98-102%.

  7. First combined total reflection X-ray fluorescence and grazing incidence X-ray absorption spectroscopy characterization of aeolian dust archived in Antarctica and Alpine deep ice cores

    Energy Technology Data Exchange (ETDEWEB)

    Cibin, G. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon OX110DE (United Kingdom); IMONT/EIM, Ente Italiano della Montagna, P.za dei Caprettari 70, 00176 Roma (Italy); Universita' degli Studi di Roma Tre, Dipartimento di Scienze Geologiche, L.go S. Leonardo Murialdo 1, 00146 Roma (Italy)], E-mail: giannantonio.cibin@diamond.ac.uk; Marcelli, A. [INFN - Laboratori Nazionali di Frascati, P.O. Box 13, 00044 Frascati (Roma) (Italy); Maggi, V. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Sala, M. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Universita degli Studi di Milano, Dipartimento di Scienze della Terra ' A. Desio' , Sez. Mineralogia, Via Mangiagalli 34, 20133 Milano (Italy); Marino, F.; Delmonte, B. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Albani, S. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Universita degli Studi di Siena, Dottorato in Scienze Polari, via Laterina 8, 53100 Siena (Italy); Pignotti, S. [IMONT/EIM, Ente Italiano della Montagna, P.za dei Caprettari 70, 00176 Roma (Italy)

    2008-12-15

    Aeolian mineral dust archived in polar and mid latitude ice cores represents a precious proxy for assessing environmental and climatic variations at different timescales. In this respect, the identification of dust mineralogy plays a key role. In this work we performed the first preliminary X-ray absorption spectroscopy (XAS) experiments on mineral dust particles extracted from Antarctic and from Alpine firn cores using grazing incidence geometry at the Fe K-edge. A dedicated high vacuum experimental chamber was set up for normal-incidence and total-reflection X-Ray Fluorescence and Absorption Spectroscopy analyses on minor amounts of mineral materials at the Stanford Synchrotron Radiation Laboratory. Results show that this experimental technique and protocol allows recognizing iron inclusion mineral fraction on insoluble dust in the 1-10 {mu}g range.

  8. Imaging exocytosis of single glucagon-like peptide-1 containing granules in a murine enteroendocrine cell line with total internal reflection fluorescent microscopy

    International Nuclear Information System (INIS)

    To analyze the exocytosis of glucagon-like peptide-1 (GLP-1) granules, we imaged the motion of GLP-1 granules labeled with enhanced yellow fluorescent protein (Venus) fused to human growth hormone (hGH-Venus) in an enteroendocrine cell line, STC-1 cells, by total internal reflection fluorescent (TIRF) microscopy. We found glucose stimulation caused biphasic GLP-1 granule exocytosis: during the first phase, fusion events occurred from two types of granules (previously docked granules and newcomers), and thereafter continuous fusion was observed mostly from newcomers during the second phase. Closely similar to the insulin granule fusion from pancreatic β cells, the regulated biphasic exocytosis from two types of granules may be a common mechanism in glucose-evoked hormone release from endocrine cells.

  9. Three-dimensional particle tracking around microstructures in water via total internal reflection fluorescence microscopy and refractive-index-matching method

    Science.gov (United States)

    Unno, Noriyuki; Nakata, Shuichiro; Satake, Shin-ichi; Taniguchi, Jun

    2016-07-01

    Multilayer nanoparticle image velocimetry (MnPIV) with a refractive-index-matching method is powerful technique for x- y- z (3D) flow measurement, because it can detect the 3D position of fluorescent particles with submicron resolution. In MnPIV, the intensity of fluorescence of a particle is used to estimate its z-position. However, it has been difficult to measure 3D flows around microstructures in water by total internal reflection fluorescence microscopy because of light scattering caused by the different refractive indices of the structures and the working fluid. By using a thermal nanoimprinting technique, we succeeded in fabricating microstructures from a polymer resin whose refractive index is equal to that of water, and we used these microstructures to perform MnPIV in water. As a result of the match between the refractive index of water and that of the microstructures, we were able to perform 3D tracking of nanoparticles around the microstructures in water.

  10. Application of the total reflection X-ray fluorescence method to the elemental analysis of brain tumors of different types and grades of malignancy

    International Nuclear Information System (INIS)

    The process of carcinogenesis may influence normal biochemical reactions leading to alterations in the elemental composition of the tissue. Total reflection X-ray fluorescence analysis (TXRF) was applied to the elemental analysis of different brain tumors. The following elements were present in all the neoplastic tissues analyzed: K, Ca, Fe, Cu, Zn and Rb. The results of the analysis showed that the elemental composition of a relatively small fragment of tissue represents satisfactorily the biochemical “signature” of a cancer. On the basis of the element concentrations determined, it was possible to differentiate between some types of brain tumors. - Highlights: • Elemental composition represents the biochemical signature of brain cancer. • The element levels differentiate some types of brain tumors. • TXRF spectrometry is a useful tool for elemental trace analysis of brain cancer

  11. First combined total reflection X-ray fluorescence and grazing incidence X-ray absorption spectroscopy characterization of aeolian dust archived in Antarctica and Alpine deep ice cores

    International Nuclear Information System (INIS)

    Aeolian mineral dust archived in polar and mid latitude ice cores represents a precious proxy for assessing environmental and climatic variations at different timescales. In this respect, the identification of dust mineralogy plays a key role. In this work we performed the first preliminary X-ray absorption spectroscopy (XAS) experiments on mineral dust particles extracted from Antarctic and from Alpine firn cores using grazing incidence geometry at the Fe K-edge. A dedicated high vacuum experimental chamber was set up for normal-incidence and total-reflection X-Ray Fluorescence and Absorption Spectroscopy analyses on minor amounts of mineral materials at the Stanford Synchrotron Radiation Laboratory. Results show that this experimental technique and protocol allows recognizing iron inclusion mineral fraction on insoluble dust in the 1-10 μg range

  12. Application of the total reflection X-ray fluorescence method to the elemental analysis of brain tumors of different types and grades of malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Lankosz, M.W., E-mail: Marek.Lankosz@fis.agh.edu.pl [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow (Poland); Grzelak, M.; Ostachowicz, B.; Wandzilak, A.; Szczerbowska-Boruchowska, M.; Wrobel, P. [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow (Poland); Radwanska, E.; Adamek, D. [Department of Neuropathology, Chair of Pathomorphology, Faculty of Medicine. Jagiellonian University, Krakow (Poland)

    2014-11-01

    The process of carcinogenesis may influence normal biochemical reactions leading to alterations in the elemental composition of the tissue. Total reflection X-ray fluorescence analysis (TXRF) was applied to the elemental analysis of different brain tumors. The following elements were present in all the neoplastic tissues analyzed: K, Ca, Fe, Cu, Zn and Rb. The results of the analysis showed that the elemental composition of a relatively small fragment of tissue represents satisfactorily the biochemical “signature” of a cancer. On the basis of the element concentrations determined, it was possible to differentiate between some types of brain tumors. - Highlights: • Elemental composition represents the biochemical signature of brain cancer. • The element levels differentiate some types of brain tumors. • TXRF spectrometry is a useful tool for elemental trace analysis of brain cancer.

  13. Portable ultrahigh-vacuum sample storage system for polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshihide, E-mail: e0827@mosk.tytlabs.co.jp; Nishimura, Yusaku F.; Suzuki, Ryo; Beniya, Atsushi; Isomura, Noritake [Toyota Central R& D Labs., Inc., Yokomichi 41-1, Nagakute, Aichi 480-1192 (Japan); Uehara, Hiromitsu; Asakura, Kiyotaka; Takakusagi, Satoru [Catalysis Research Center, Hokkaido University, Kita 21-10, Sapporo, Hokkaido 001-0021 (Japan); Nimura, Tomoyuki [AVC Co., Ltd., Inada 1450-6, Hitachinaka, Ibaraki 312-0061 (Japan)

    2016-03-15

    A portable ultrahigh-vacuum sample storage system was designed and built to investigate the detailed geometric structures of mass-selected metal clusters on oxide substrates by polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy (PTRF-XAFS). This ultrahigh-vacuum (UHV) sample storage system provides the handover of samples between two different sample manipulating systems. The sample storage system is adaptable for public transportation, facilitating experiments using air-sensitive samples in synchrotron radiation or other quantum beam facilities. The samples were transferred by the developed portable UHV transfer system via a public transportation at a distance over 400 km. The performance of the transfer system was demonstrated by a successful PTRF-XAFS study of Pt{sub 4} clusters deposited on a TiO{sub 2}(110) surface.

  14. A novel form of Total Internal Reflection Fluorescence Microscopy (LG-TIRFM) reveals different and independent lipid raft domains in living cells.

    Science.gov (United States)

    Asanov, Alexander; Zepeda, Angélica; Vaca, Luis

    2010-02-01

    In the present study we have applied a novel form of Total Internal Reflection Fluorescence Microscopy (LG-TIRFM) in combination with fluorescently labeled cholera toxin to the study of lipid rafts dynamics in living cells. We demonstrate the usefulness of such approach by showing the dynamic formation/disaggregation of islands of cholera toxin on the surface of cells. Using multicolor LG-TIRFM with co-localization studies we show for the first time that two receptors previously identified as constituents of lipid rafts are found on different and independent "raft domains" on the cell plasma membrane. Furthermore, LG-TIRFM studies revealed limited association and dissociation of both domains overtime on different areas of the plasma membrane. The implications of different "raft domains" on cell physiology are discussed.

  15. Multielement analysis of aerosols by means of neutron activation analysis and X-ray fluorescence analysis with totally reflecting sample holders

    International Nuclear Information System (INIS)

    For the analysis of aerosol samples on filters several methods for the energy dispersive X-ray Fluorescence Analysis with Totally Reflecting Sample Holder (TRXFA) with Mo-exitation were developed and investigated for systematic errors. The elements K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Pb and Ba are detectable with high sensitivity. For the improved detection of short lifed nuclides (tsub(1/2) = 2 - 50 h) with the Neutron Activation Analysis (NAA) a radiochemical procedure for the separation of Na-24 and Br-82 was developed. The results of TRXFA and NAA correspond well. The capabilities of the developed methods were demonstrated on a set of size-fractionated aerosol samples. (orig.)

  16. Monitoring environmental pollution of trace elements in tree-rings by synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Brienza, Sandra Maria B. [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil) Faculdade de Ciencias Matematicas, da Natureza e de Tecnologia da Informacao]. E-mail: sbrienza@unimep.br; Medeiros, Jean Gabriel S.; Tomazello Filho, Mario [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mail: jeangm@esalq.usp.br; mtomazel@esalq.usp.br; Zucchi, Orgheda L.A.D. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br

    2005-07-01

    This paper aims to study the environmental pollution in the tree development, as a manner to evaluate its use as bioindicator in urban and country sides. The sample collecting was carry out in Piracicaba city, Sao Paulo State, that presents high level of environmental contamination of the water, soil and air, due industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. It was selected the Caesalpinia peltophoroides ('Sibipiruna') specie because its very used in urban arborization. It was employed the analytical technique named total reflection X-ray fluorescence (TXRF) to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was done in the Brazilian Synchrotron Light Laboratory, using a white beam for excitation and a Si(Li) detector for characteristic X-ray detection. It was quantified the P, K, Ca, Ti, Fe, Sr, Ba e Pb elements. (author)

  17. Determination of trace elements in Syrian medicinal plants and their infusions by energy dispersive X-ray fluorescence and total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Khuder, A. [Department of Chemistry, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)], E-mail: scientific2@aec.org.sy; Sawan, M.Kh.; Karjou, J. [Department of Chemistry, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic); Razouk, A.K. [Department of Agriculture, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2009-07-15

    X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise (Anisum vulgare), licorice root (Glycyrrhiza glabra), and white wormwood (Artemisia herba-alba)

  18. Quantification of modifiers in advanced materials based on zinc oxide by total reflection X-ray fluorescence and inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Filatova, Daria G.; Alov, Nikolai V.; Vorobyeva, Natalia A.; Rumyantseva, Marina N.; Sharanov, Pavel Yu.; Seregina, Irina F.; Gaskov, Alexander M.

    2016-04-01

    A novel approach to quantification of Ga and Zn modifiers in advanced materials based on zinc oxide is presented. The approach includes a combination of total reflection X-ray fluorescence (TXRF) and inductively coupled plasma mass spectrometry (ICP-MS) for determination and validation of the results. It is suggested to use aqueous standards for the direct determination of elements in powder samples by TXRF with a relative standard deviation no more than sr = 0.11. The accuracy of these results was proved by ICP-MS after the sample decomposition, sr(In) = 0.05, sr(Ga) = 0.06 and sr(Zn) = 0.06. It was established that there is a possibility to determine indium above 300 ppb on the background of K-M3 line of argon.

  19. Biomonitoring of environmental pollution using growth tree rings of Tipuana tipu: Quantification by synchrotron radiation total reflection X-ray fluorescence

    Science.gov (United States)

    Geraldo, S. M.; Canteras, F. B.; Moreira, S.

    2014-02-01

    Currently, many studies use the bioindicators to qualitatively and/or quantitatively measure pollution. The analyses of tree growth rings represent one such bioindicator as changes in the environment are often recorded as impressions in the wood. The main objective of the present study is to examine the growth rings of Tipuana tipu - a member of the Leguminosae family that is native to Argentina and Bolivia and was introduced in Brazil as an ornamental plant - for potentially toxic elements. T. tipu is one of the most common trees in the urban landscape of Sao Paulo city and would provide an accurate reflection of environment changes. Tree ring samples previously dated using Synchrotron Radiation Total Reflection X-ray Fluorescence were collected from strategic locations in Sao Paulo. These locations include Piracicaba (SP) that has little access and small flow traffic and the campus of the University of São Paulo. Some trace elements present concentrations higher than considered as normal in some periods. In São Paulo city, samples collected from the campus of University of São Paulo (Butantã), showed the highest toxicity, with concentrations above the tolerable limit for the elements: Cr, Cu, and Pb. For the samples collected in Piracicaba city, one sample presented highest concentrations for the majority of the elements when compared to the other four samples collected at the same place, exceeding the toxicity limits for: Cr, Ni, Cu, and Pb.

  20. Preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for samples from Upper and Lower Cretaceous strata, Maverick Basin, south Texas

    Science.gov (United States)

    Hackley, Paul C.; Dennen, Kristin O.; Gesserman, Rachel M.; Ridgley, Jennie L.

    2009-01-01

    The Lower Cretaceous Pearsall Formation, a regionally occurring limestone and shale interval of 500-600-ft maximum thickness (Rose, 1986), is being evaluated as part of an ongoing U.S. Geological Survey (USGS) assessment of undiscovered hydrocarbon resources in onshore Lower Cretaceous strata of the northern Gulf of Mexico. The purpose of this report is to release preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for Pearsall Formation, Glen Rose Formation, Hosston Formation, Austin Group, and Eagle Ford Group samples from the Maverick Basin in south Texas in order to aid in the characterization of these strata in this area. The preliminary nature of this report and the data contained herein reflect that the assessment and characterization of these samples is a work currently in progress. Pearsall Formation subdivisions are, in ascending stratigraphic order, the Pine Island Shale, James Limestone, and Bexar Shale Members (Loucks, 2002). The Lower Cretaceous Glen Rose Formation is also part of the USGS Lower Cretaceous assessment and produces oil in the Maverick Basin (Loucks and Kerans, 2003). The Hosston Formation was assessed by the USGS for undiscovered oil and gas resources in 2006 (Dyman and Condon, 2006), but not in south Texas. The Upper Cretaceous Austin Group is being assessed as part of the USGS assessment of undiscovered hydrocarbon resources in the Upper Cretaceous strata of the northern Gulf of Mexico and, along with the Upper Cretaceous Eagle Ford Group, is considered to be an important source rock in the Smackover-Austin-Eagleford Total Petroleum System (Condon and Dyman, 2006). Both the Austin Group and the Eagle Ford Group are present in the Maverick Basin in south Texas (Rose, 1986).

  1. Room temperature trapping of stibine and bismuthine onto quartz substrates coated with nanostructured palladium for total reflection X-ray fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Vanesa; Costas-Mora, Isabel; Lavilla, Isela; Bendicho, Carlos, E-mail: bendicho@uvigo.es

    2015-05-01

    In this work, a novel method for determining Sb and Bi based on the trapping of their covalent hydrides onto quartz reflectors coated with immobilized palladium nanoparticles (Pd NPs) followed by total reflection X-ray fluorescence (TXRF) analysis is proposed. Pd NPs were synthesized by chemical reduction of the metal precursor using a mixture of water:ethanol as mild reducing agent. Silanization using 3-mercaptopropyltrimethoxysilane (MPTMS) was performed for the immobilization of Pd NPs onto the quartz substrates. Volatile hydrides (stibine and bismuthine) generated by means of a continuous flow system were flushed onto the immobilized Pd NPs and retained by catalytic decomposition. As a result of the high catalytic activity of the nanostructured film, trapping can be performed at ambient temperature with good efficiency. Limits of detection (LODs) were 2.3 and 0.70 μg L{sup −1} for Sb and Bi, respectively. Enrichment factors of 534 and 192 were obtained for Sb and Bi, respectively. The new method was applied for the analysis of several matrices (milk, soil, sediment, cutaneous powder). Recoveries were in the range of 98.4–101% for both elements with a relative standard deviation of 2.5% (N = 5). - Highlights: • A novel method for trapping covalent hydrides of antimony and bismuth is proposed. • Emphasis is placed on the application of Pd nanoparticles as trapping surface. • The nanostructured surface provides high catalytic activity at ambient temperature. • Analysis by total reflection X-ray fluorescence is performed. • Determination of Bi and Sb in different matrices is carried out.

  2. Is there seismic attenuation in the mantle?

    Science.gov (United States)

    Ricard, Y.; Durand, S.; Montagner, J.-P.; Chambat, F.

    2014-02-01

    The small scale heterogeneity of the mantle is mostly due to the mixing of petrological heterogeneities by a smooth but chaotic convection and should consist in a laminated structure (marble cake) with a power spectrum S(k) varying as 1/k, where k is the wavenumber of the anomalies. This distribution of heterogeneities during convective stirring with negligible diffusion, called Batchelor regime is documented by fluid dynamic experiments and corresponds to what can be inferred from geochemistry and seismic tomography. This laminated structure imposes density, seismic velocity and potentially, anisotropic heterogeneities with similar 1/k spectra. A seismic wave of wavenumber k0 crossing such a medium is partly reflected by the heterogeneities and we show that the scattered energy is proportional to k0S(2k0). The reduction of energy for the propagating wave appears therefore equivalent to a quality factor 1/Q∝k0S(2k0). With the specific 1/k spectrum of the mantle, the resulting apparent attenuation should therefore be frequency independent. We show that the total contribution of 6-9% RMS density, velocity and anisotropy would explain the observed S and P attenuation of the mantle. Although these values are large, they are not unreasonable and we discuss how they depend on the range of frequencies over which the attenuation is explained. If such a level of heterogeneity were present, most of the attenuation of the Earth would be due to small scale scattering by laminations, not by intrinsic dissipation. Intrinsic dissipation must certainly exist but might correspond to a larger, yet unobserved Q. This provocative result would explain the very weak frequency dependence of the attenuation, and the fact that bulk attenuation seems negligible, two observations that have been difficult to explain for 50 years.

  3. Precision Model for Microwave Rotary Vane Attenuator

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom

    1979-01-01

    A model for a rotary vane attenuator is developed to describe the attenuator reflection and transmission coefficients in detail. All the parameters of the model can be measured in situ, i.e., without diassembling any part. The tranmission errors caused by internal reflections are calculated from ...

  4. Determination of Proteins by Measuring Total Internal-reflected Resonance Light Scattering Signals on Water/Tetrachloromethane Interface with Evans Blue and Cetyltrimethylammonium Bromide

    Institute of Scientific and Technical Information of China (English)

    HUANG Cheng-zhi; FENG Ping; LI Yuan-fang; ZHAO Hua-wen

    2005-01-01

    A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane(H2O/CCl4) interface. In an aqueous medium with pH value in the range of 3.29-3.78, electrostatic attraction occurs between the negatively charged Evans Blue(EB) and positively charged proteins, forming hydrophobic ion associates and resulting in EB-protein adsorption on H2O/CCl4 interface. The presence of cetyltrimethylammonium bromide prompts this adsorption, resulting in strongly enhanced TIR-RLS signals. The intensity of the enhanced TIR-RLS at 360-370 nm was found to be proportional to the concentration of proteins. For bovine serum albumin and human serum albumin, the linear range of detection is 0.07-1.2 μg/mL and the limits of detection are 6.68 and 6.30 ng/mL(3σ), respectively, while for lysozyme, the linear range of detection is 0.06-1.0 μg/mL and the limit of detection is 6.0 ng/mL(3σ). The content of the total albumin in a human urine sample could be directly determined by using the standard addition method with a percent recovery of 97.6%-104.1%, and the RSD ranging from 1.9% to 4.2%.

  5. Attenuation Correction of Reflectivity for X-Band Dual-Polarization Radar%X波段双线偏振气象雷达反射率的衰减订正

    Institute of Scientific and Technical Information of China (English)

    毕永恒; 刘锦丽; 段树; 吕达仁; 苏德斌; 陈羿辰

    2012-01-01

    X波段天气雷达的强衰减是影响其探测精度与应用推广的主要问题.本文旨在寻求适用于降水过程中对X波段双偏振雷达进行衰减订正的一种方法.在订正前先对雷达数据进行了质量控制和预处理;在分析了国内外已有订正方法的基础上,选择并改进了自适应约束算法作为雷达反射率进行衰减订正的方法;最后进行方法的效果验证.既对衰减订正前后反射率与同时段S波段雷达反射率作对比,又对偏振参数KDP~ZH、AH~ZH之间关系的变化进行分析,不仅如此,还直接与地面降水实况作比较等.分析表明,对X波段双线偏振雷达进行反射率衰减订正后的效果显著优于订正前,特别是,当存在较大范围(含对流型)降雨时,采用此种订正方法可以明显提高降水的估测精度.%Strong attenuation in rain affects the detection accuracy and application of the X-band radar. This paper aims to seek a method of attenuation correction for X-band dual-polarization radar in precipitation. Before correction, the radar data are pre-processed with quality controls after analyzing all the methods from the past works, an attenuation correction algorithm is developed which is based on the self-consistent method with constraints; finally some validation methods are studied. Some comparisons are made between the corrected composite reflectivity of the X-band radar and a nearby S-band radar observed at the same time; moreover, the corrected relationships between KDP vs. Zh and Ah vs. Zh are also similar to the theoretical values predicted by scattering simulation. In addition, the authors also compare the corrected reflectivity with the surface rain-gauge observations. The analysis results indicate that the corrected reflectivity is more significant than the uncorrected one; specially for the larger area of rainfall (including convective rainfall) using the above attenuation correction algorithm for X-band radar

  6. Control algorithms for dynamic attenuators

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Scott S., E-mail: sshsieh@stanford.edu [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Pelc, Norbert J. [Department of Radiology, Stanford University, Stanford California 94305 and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States)

    2014-06-15

    Purpose: The authors describe algorithms to control dynamic attenuators in CT and compare their performance using simulated scans. Dynamic attenuators are prepatient beam shaping filters that modulate the distribution of x-ray fluence incident on the patient on a view-by-view basis. These attenuators can reduce dose while improving key image quality metrics such as peak or mean variance. In each view, the attenuator presents several degrees of freedom which may be individually adjusted. The total number of degrees of freedom across all views is very large, making many optimization techniques impractical. The authors develop a theory for optimally controlling these attenuators. Special attention is paid to a theoretically perfect attenuator which controls the fluence for each ray individually, but the authors also investigate and compare three other, practical attenuator designs which have been previously proposed: the piecewise-linear attenuator, the translating attenuator, and the double wedge attenuator. Methods: The authors pose and solve the optimization problems of minimizing the mean and peak variance subject to a fixed dose limit. For a perfect attenuator and mean variance minimization, this problem can be solved in simple, closed form. For other attenuator designs, the problem can be decomposed into separate problems for each view to greatly reduce the computational complexity. Peak variance minimization can be approximately solved using iterated, weighted mean variance (WMV) minimization. Also, the authors develop heuristics for the perfect and piecewise-linear attenuators which do not requirea priori knowledge of the patient anatomy. The authors compare these control algorithms on different types of dynamic attenuators using simulated raw data from forward projected DICOM files of a thorax and an abdomen. Results: The translating and double wedge attenuators reduce dose by an average of 30% relative to current techniques (bowtie filter with tube current

  7. Application of total-reflection X-ray fluorescence spectrometry and high-performance liquid chromatography for the chemical characterization of xylem saps of nickel contaminated cucumber plants

    Science.gov (United States)

    Mihucz, Victor G.; Tatár, Eniko; Varga, Anita; Záray, Gyula; Cseh, Edit

    2001-11-01

    Total-reflection X-ray fluorescence (TXRF) spectrometry, reversed-phase (RP) and size-exclusion (SE) high-performance liquid chromatography (HPLC) methods were applied for the characterization of low-volume xylem sap of control and nickel contaminated cucumber plants growing in hydroponics containing urea as the sole nitrogen source. In these saps collected for 1 h, Ca, K, Fe, Mn, Ni, Zn, as well as malic, citric and fumaric acids were determined. The SEC measurements showed that macromolecules were not detectable in the samples. Nickel contamination had minimum impact on the organic acid transport, however, the transport of Zn, K and Fe was reduced by 50, 22 and 11%, respectively. This observation supports the results of our earlier experiments when nitrate ions were used as the sole nitrogen form. At the same time, the fresh root weight and the volume of the collected xylem sap increased by 36 and 85%, respectively. Therefore, nickel addition seemed to decrease the urea toxicity of the plants. By pooling the eluting fractions of the SEC column, which were 10-fold concentrated by freeze-drying, the series of the resulted samples were analyzed by the TXRF spectrometry and RP-HPLC. The three organic acids could be identified in only one of the fractions, which contained Fe and, in the case of the contaminated plants, Ni in detectable concentration. However, considerable parts of these two elements and Mn, as well as practically the total amounts of Cu may be transported by unidentified organic compounds in the xylem.

  8. Study of interaction of iron and lead during their uptake process in wheat roots by total-reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Varga, Anita; Záray, Gyula; Fodor, Ferenc; Cseh, Edit

    1997-07-01

    Microwave assisted acidic digestion and total-reflection X-ray fluorescence spectrometry (TXRF) was used for the determination of lead and iron in wheat roots cultured in CaSO 4 solution, and treated with Pb(NO 3) 2 and Fe(III)-citrate or Fe(III)-EDTA under controlled conditions, respectively. It was established that lead has a stimulation effect on the iron uptake in the presence of Fe(III)-citrate. The lead uptake, however, is hardly influenced by iron independently from the complex forming agents applied. To check the stability of the accumulated iron and lead constituents, some of the roots were washed with various solutions and the removable iron and lead were also measured by TXRF. These experiments indicate that the presence of lead results in higher stability of iron constituents in the root; however, iron does not have any effect on the lead constituents, the stabilities of which increase in the order Pb-citrate

  9. Quantification of potentially toxic elements in sewage and sludge from treatment plants in the cities of Campinas and Jaguariuna using synchrotron radiation total reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    The rapid urban and industrial development in last decades has brought as one of the consequences, changes in the environment. The lack of planning of city growth is, today, one of the major causes of water pollution including residential, industrial, agricultural, and hospital waste. The metals contamination is a major problem, causing serious changes to the environment, causing harm to human health. The sludge generated at sewage treatment plants, is an important source of nutrients and organic matter, and therefore it can also be reused mainly for agricultural use, since contaminants are removed. The cities of Campinas and Jaguariuna are inserted in the Campinas Metropolitan Region (CMR), one of the most dynamic regions in the Brazilian economy. Therefore, to study the anthropogenic influences of the cities, evaluated the quality of raw and treated effluent and the sludge generated in sewage treatment plants, especially with regard to heavy metals. Measurements of metals were performed by Synchrotron Radiation Total Reflection X-ray Fluorescence. For treated effluent data were compared to CONAMA 357 law and Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb showed concentrations in according with the law. To reuse in agriculture the contents were compared to the limits defined by CETESB and some elements had concentrations above to the permitted preventing its reuse. For sludge, Cr, Ni, Cu, Zn, Ba and Pb, in the two treatment plants studied, the concentrations were lower than the maximum permissible values established by CONAMA 375 law allowing the sludge application sludge on agricultural land. (author)

  10. Chemical state analysis of trace-level alkali metals sorbed in micaceous oxide by total reflection X-ray photoelectron spectroscopy

    Science.gov (United States)

    Baba, Y.; Shimoyama, I.; Hirao, N.

    2016-10-01

    In order to determine the chemical states of radioactive cesium (137Cs or 134Cs) sorbed in clay minerals, chemical states of cesium as well as the other alkali metals (sodium and rubidium) sorbed in micaceous oxides have been investigated by X-ray photoelectron spectroscopy (XPS). Since the number of atoms in radioactive cesium is extremely small, we specially focused on chemical states of trace-level alkali metals. For this purpose, we have measured XPS under X-ray total reflection (TR) condition. For cesium, it was shown that ultra-trace amount of cesium down to about 100 pg cm-2 can be detected by TR-XPS. This amount corresponds to about 200 Bq of 137Cs (t1/2 = 30.2 y). It was demonstrated that ultra-trace amount of cesium corresponding to radioactive cesium level can be measured by TR-XPS. As to the chemical states, it was found that core-level binding energy in TR-XPS for trace-level cesium shifted to lower-energy side compared with that for thicker layer. A reverse tendency is observed in sodium. Based on charge transfer within a simple point-charge model, it is concluded that chemical bond between alkali metal and micaceous oxide for ultra-thin layer is more polarized that for thick layer.

  11. Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vivo exposure to mercury: A study using synchrotron radiation total reflection X-ray fluorescence

    Science.gov (United States)

    Mantuano, Andrea; Pickler, Arissa; Barroso, Regina C.; de Almeida, André P.; Braz, Delson; Cardoso, Simone C.; Gonzalez, Marcelo S.; Figueiredo, Marcela B.; Garcia, Eloi S.; Azambuja, Patricia

    2012-05-01

    In recent years, the effects of pollution on the health of humans and other vertebrates were extensively studied. However, the effects on some invertebrates are comparatively unknown. Recent studies have demonstrated that toxic metals interfere with the reproduction, development and immune defenses of some terrestrial and marine invertebrates. Some environmental conditions including pollution produce chronic and acute effects on different animal's organs and systems. In this work, we investigated changes in the concentrations of Cl, K, Ca, Fe and Zn in Rhodnius prolixus as insect model. The elements were quantified using urine and hemolymph samples collected on different days after feeding the insects with blood containing HgCl2. The synchrotron radiation total reflection X-ray fluorescence measurements were carried at the X-ray fluorescence beamline facility in Brazilian Synchrotron Light Laboratory. The observation reveals that the calcium level was higher in the hemolymph than in urine. On the other hand, the urine collected from insects treated with HgCl2 showed higher level of Cl than hemolymph samples. Ca, Fe and Zn concentrations decrease drastically in urine samples collected after 2 days of HgCl2 treatment. The regulation of triatomines excretion was discussed pointing out the importance of trace elements.

  12. Characterization of high-k gate dielectric and metal gate electrode semiconductor samples with a total reflection X-ray fluorescence spectrometer

    International Nuclear Information System (INIS)

    The versatility of a total reflection X-ray fluorescence (TXRF) spectrometer in the analysis of semiconductor samples will be demonstrated. While TXRF has a well-established place in trace metals analysis on silicon wafers, the practice of characterizing new films with TXRF is not routine in the semiconductor industry. In this paper, we will examine the monitoring of high-k film growth on silicon wafers by TXRF. We will show that a linear relationship between cycles of film deposition and TXRF signal is possible with proper analytical conditions. This signal can be converted to film thickness by normalizing to cross-sectional measurement from transmission electron microscopy (TEM). Information about the interface between the deposited high-k layer and the silicon substrate can also be determined from TXRF data. Secondary ion mass spectrometry data of a chlorine species at the interface of the high-k and silicon were collaborated with TXRF data. Critical angle measurements were taken on ruthenium and ruthenium dioxide films to extract physical characteristics and these results were compared to those from other techniques

  13. Determination of trace elements in planktonic microcrustaceans using total reflection X-ray fluorescence (TXRF): First results from two Chilean lakes

    Energy Technology Data Exchange (ETDEWEB)

    Woelfl, Stefan; Mercado, Susana; Villalobos, Lorena [Instituto de Zoologia, Universidad Austral de Chile, Casilla 567, Valdivia (Chile); Mages, Margarete; Ovari, Mihaly [Department of Inland Water Research Magdeburg, UFZ Centre for Environmental Research Leipzig-Halle, Brueckstrasse 3a, 39114, Magdeburg (Germany); Encina, Francisco [Escuela de Ciencias Ambientales, Facultad de Ciencias, Universidad Catolica de Temuco, Montt 056, Temuco (Chile)

    2004-02-01

    First results are described from the application of a recently developed dry method for determination of elements in single specimens of freshwater microcrustaceans, using total reflection X-ray fluorescence spectrometry (TXRF). This method is a powerful, non-destructive technique for quantifying the trace element content of minute biological samples with a dry weight of 3-50 {mu}g. Three different freshwater microcrustaceans were sampled, from the natural, uncontaminated Lake Laja and from the artificial Rapel reservoir which is slightly contaminated by drainage water from a copper mine. Single specimens of Daphnia pulex, Bosmina chilensis, and Ceriodaphnia dubia were prepared using a modification of the dry method and measured by TXRF. The results showed that both As, Mn, Fe, Ni, Zn, and Cu content and the bioaccumulation of these metals were usually significantly different between the microcrustaceans from the two lakes. The largest difference was found for Cu which was eight times more concentrated in the two microcrustaceans from Rapel reservoir than it was in D. pulex from Lake Laja. (orig.)

  14. Study on trace elements behaviour in cancerous and healthy tissues of colon, breast and stomach: Total reflection X-ray fluorescence applications

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, T. [Centro de Fisica Atomica da Univeridade de Lisboa, Departamento de Fisica da Faculdade de Ciencias, Av. Prof. Gama Pinto, 2, 1649-00, Lisboa (Portugal); Carvalho, M.L., E-mail: luisa@cii.fc.ul.p [Centro de Fisica Atomica da Univeridade de Lisboa, Departamento de Fisica da Faculdade de Ciencias, Av. Prof. Gama Pinto, 2, 1649-00, Lisboa (Portugal); Von Bohlen, A.; Becker, M. [Institute for Analytical Sciences (ISAS), Bunsen-Kirchhoff-Str. 11, 44139 Dortmund (Germany)

    2010-06-15

    In this work Total-reflection X-ray fluorescence (TXRF) was used to analyse healthy and cancerous tissues of the same individual along several contiguous thin sections of each tissue. Thirty two samples (16 pairs) of breast tissue, 30 samples (15 pairs) of intestine tissue and 10 samples (5 pairs) of stomach tissue were analysed. The samples were obtained in Civil Hospitals of Germany (Dortmund) and Portugal (Lisbon). The elemental distribution of P, S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr and Pb in these samples was studied. Descriptive statistics based on bar graphics and hypotheses tests and also an automatic classification based on hierarchical grouping analysis was used for the several analysed tissues. It was shown that the behaviour of the elements is tissue dependent. Some elements, like P and K exhibit the same behaviour in all the analysed tissue types. They have increased concentrations in all cancerous tissues. Unlike, other elements like Br show completely different behaviour depending on the tissue: similar concentration in healthy and cancerous stomach, decreased levels in colon cancerous tissues and enhanced concentrations in breast was observed. Moreover cancer tissues present decreased Se concentrations on colon and increased on breast.

  15. Elemental concentration analysis in brain of young, adult and old wistar rats by X-ray total reflection fluorescence with synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, Renata F.B.; Jesus, Edgar F.O. de; Lopes, Ricardo T. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. de Instrumentacao Nuclear]. E-mail: renata@lin.ufrj.br; Anjos, Marcelino J. dos [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: marcelin@lin.ufrj.br; Carmo, Maria da Graca T. do [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Nutricao]. E-mail: tcarmo@editema.com.br; Rocha, Monica S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Farmacologia]. E-mail: mrocha@farmaco.ufrj.br; Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil]. E-mail: silvana@fec.unicamp.br; Martinez, Ana Maria B. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Histologia]. E-mail: martinez@histo.ufrj.br

    2005-07-01

    The mainly goal of this work is to compare the elemental concentrations with different postnatal ages (2, 8, 20, 48 and 72 weeks) at three different regions of the rat brain, namely temporal cortex, entorhinal cortex and hippocampus by X-Ray Total Reflection Fluorescence with Synchrotron Radiation (SR-TXRF). The advantages for this analytical multielemental technique are: low background, linear relation in the quantification analysis and low detection limit (ngg{sup -1}). The fluorescence measurements were carried out at XRF beamline at the Brazilian Light Synchrotron Laboratory (Campinas, Brazil). It was possible to determine the following elements: Ti, Mn, Fe, Cu, Zn, Br, Rb and Sr (at trace level) and P, S, Cl, K and Ca (at major levels) were determined in the brain. In general, Fe levels were more pronounced in entorhinal cortex. There was also observed that the hippocampus of the old female rat presented the highest concentrations for Al, P, S, K, and Zn. In contrast to this, the hippocampus and entorhinal cortex presented the less levels for Al and K in the young animals. On the other hand, Cl levels were more conspicuous in the entorhinal cortex of the oldest male animal studied. (author)

  16. Analysis in crab tissues and in sediment of estuary from Iguape (Sao Paulo, Brazil) by total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, Marcos J. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil)], E-mail: mjsalvador1531@yahoo.com.br; Sawazaki, David T.A.; Zucchi, Orgheda L.A. Domingues [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas], E-mail: david_tatsuo@hotmail.com, E-mail: olzucchi@fcfrp.usp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo], E-mail: aesvives@unimep.br; Hattori, Gustavo Y. [Universidade Federal do Amazonas, Benjamin Constant (Brazil). Faculdade de Ciencias Agrarias], E-mail: hattori@ufam.edu.br

    2007-07-01

    We report the use of Synchrotron Radiation Total Reflection X-Ray Fluorescence analysis (SR-TXRF) as a technique for macro, micro and trace elements determination in the tissues of the crab Ulcides cordatus and in the sediments from the Iguape estuary (Sao Paulo, Brazil) for environmental pollution control and toxicological evaluation. The analyses were performed on the U. cordatus (muscles and hepatopancreas) and on sediments from 24 sites of the Iguape estuary (Sao Paulo, Brazil). Tissues and sediments samples were analyzed by SRTXRF after digestion in an open system, using Ga as internal standard. Potassium (K), Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr, and Ba were the elements detected in crab hepatopancreas at concentration ranging from 0.516 (Mn) to 2061 (K) mug/g. Muscles samples presented the elements K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Br and Sr at concentrations ranging from 0.043 (Ni) to 1917 (K) mug/g. Potassium (K), Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Sn, Ce, and Pb were the elements detected in the sediment samples with concentration between 3.8 (Cu) and 14628 (Fe)mug/g. (author)

  17. Total reflection X-ray fluorescence measurements of S and P in proteins using a vacuum chamber specially designed for low Z elements

    Energy Technology Data Exchange (ETDEWEB)

    Rauwolf, M., E-mail: mrauwolf@ati.ac.at [Atominstitut, Technische Universität Wien, Stadionallee 2, Vienna 1020 (Austria); Vanhoof, C.; Tirez, K.; Maes, E. [Flemish Institute for Technological Research NV, Boeretang 200, Mol 2400 (Belgium); Ingerle, D.; Wobrauschek, P.; Streli, C. [Atominstitut, Technische Universität Wien, Stadionallee 2, Vienna 1020 (Austria)

    2014-11-01

    As the ratio of phosphorus and sulfur in proteins allows the determination of the phosphorylation degree in proteins, the absolute determination of phosphorus and sulfur in organic samples is of growing interest. While it takes some effort to quantify phosphorus and sulfur with inductively coupled quadrupole plasma mass spectrometry (ICP-QMS), total reflection X-ray fluorescence analysis (TXRF) allows easy quantification. In the presented work, the low Z TXRF spectrometer at the Atominstitut was used to analyze phosphorus and sulfur in proteins. Although the preparation of the protein samples proved to be more difficult than originally expected, it could be shown that TXRF is well suited for the determination of P and S in proteins. The obtained lower limits of detection (LLD) for P and S in proteins were extrapolated for 1000s and were 34 pg and 19 pg, respectively. The importance of height scans for each sample to exclude heterogeneities was demonstrated. - Highlights: • Low Z TXRF spectrometry was used to analyze phosphorus and sulfur in proteins. • TXRF is well suited for the determination of P and S in proteins. • Good detection limits for P (34 pg) and S (19 pg) were achieved. • Due to the detection limits, we propose that TXRF is a suitable method to analyze protein fractions.

  18. Characterization by Total Reflection X-ray Fluorescence Spectrometry of filtered water into the cave under the Sun Pyramid in Teotihuacan City

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, T. [National University of Mexico, Faculty of Chemistry, Building D, CU, O4510, Mexico, D.F. (Mexico)], E-mail: tmc@servidor.unam.mx; Zarazua, G.; Avila-Perez, P. [National Institute of Nuclear Research, Carr. Mexico-Toluca Km 36.5, 52045, Salazar, Ocoyoacac, Edo. de Mexico (Mexico); Juarez, F. [National University of Mexico, Institute of Geophysics, Circuito Institutos, CU, 04510 Mexico, D.F. (Mexico); Cabrera, L. [National University of Mexico, Faculty of Chemistry, Building D, CU, O4510, Mexico, D.F. (Mexico); Martinez, G. [Coordinacion Nacional de Conservacion del Patrimonio Cultural, Xicotencatl y General Anaya s/n., 04120, Mexico, D.F. (Mexico)

    2008-12-15

    Teotihuacan (50 km north-east Mexico City) was the most important ancient city in Mesoamerica and it flourished 200-750 AC. It is situated in the central part of the Valley of Teotihuacan, in Central Mexico. This study was carried out in the 102 m-long cave under the largest single construction, the massive Sun Pyramid, being located on the east side of the 'Avenue of the Dead', in the northern half-part of the city. The study shows the results of Total Reflection X-ray Fluorescence Spectrometry analysis and other techniques of a water sample obtained from the inside of the cave. The inside temperature ranged between 19 and 22 deg. C; relative humidity was between 98 and 99.3%; water-dropping velocity (water de-sorption capability) was 13.5 {mu}L min{sup -1}. Water samples from wells around the site were analyzed too. Metal concentration in all of the water samples matches the characteristics of the sampling site, well's depth, soil and minerals.

  19. Experimental methodology and spectral analysis for the determination of mercury by means of Total Reflection X-Ray Fluorescence, using gold amalgams

    International Nuclear Information System (INIS)

    Full text: In this work is described an experimental and statistical method for the determination of ionic mercury in liquid samples by means of Total Reflection X-Ray Fluorescence. The obtained results by the application of this technique provide reliable results, that have been verified by means of the measurement of benchmarks prepared ad hoc. The usual procedure for the preparation of a sample for TXRF is not applicable for the determination of mercury, because the high vapor pressure of this element causes its evaporation and lost of the target holder. To avoid this effect, the developed method proposes a plaster or previous deposition of a thin layer of gold in the reflector. Later on, it is left in contact with an ionic solution of mercury with the gold, to facilitate the formation of an amalgam. Finally, an analysis is carried out by means of traditional form of TXRF. As the peaks of mercury and gold are overlapped, we developed a formulation that describes the obtained spectrum, in order to derive a data handling that allows to access to precise results; at the same time, it estimates the detection of the method. Two equations are proposed for the analysis, which are applied to the obtained spectra and compare the results. Using a X-ray tube with anode of molybdenum, at 40 kV and 20 mA, the limit of detection obtained for a sample of 10 ml (with 2000 s of counting time) is 250 ppb, lower indeed than the lower limit of ppm units recommended by the EPA

  20. Fluorescently-Labeled Estradiol Internalization and Membrane Trafficking in Live N-38 Neuronal Cells Visualized with Total Internal Reflection Fluorescence Microscopy.

    Science.gov (United States)

    Kisler, Kassandra; Chow, Robert H; Dominguez, Reymundo

    2013-04-20

    Estradiol is a steroid hormone that binds and activates estradiol receptors. Activation of these receptors is known to modulate neuronal physiology and provide neuroprotection, but it is not completely understood how estradiol mediates these actions on the nervous system. Activation of a sub-population of estradiol receptor-α (ERα), originally identified as a nuclear protein, localizes to the plasma membrane and appears to be a critical step in neuroprotection against brain injury and disease. Previously we showed that estradiol stimulates the rapid and transient trafficking of plasma membrane ERα in primary hypothalamic neurons, and internalization of membrane-impermeant estradiol (E6BSA-FITC) into cortical neuron endosomes in vitro. These findings support the concept that estradiol activates and down-regulates plasma membrane ERα by triggering endocytosis. Here, we use TIRFM (total internal reflection fluorescence microscopy) to image the trafficking of E6BSA-FITC, and GFP-labeled ERα, in live cells in real time. We show that activation of plasma membrane ERs by E6BSA-FITC result in internalization of the fluorescent ligand in live N-38 neurons, an immortalized hypothalamic cell line. Pretreatment with ER antagonist ICI 182,780 decreased the number of E6BSA-FITC labeled puncta observed. We also observed in live N-38 neurons that E6BSA-FITC co-localized with FM4-64 and LysoTracker fluorescent dyes that label endosomes and lysosomes. Our results provide further evidence that plasma membrane ERα activation results in endocytosis of the receptor. PMID:24353903

  1. Evaluation of growth tree rings of Tipuana Tipu as biomonitoring of environmental pollution by synchrotron radiation total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Silvana; Geraldo, Simoni Michetti; Canteras, Felippe Benavente, E-mail: silvana@fec.unicamp.br, E-mail: felippe.canteras@gmail.com [Universidade Estadual de Campinas (FEC/UNICAMP), Campinas, SP (Brazil). Dept. de Saneamento e Ambiente

    2013-07-01

    The bioindicators, plants or animals capable to present qualitative and/or quantitative answers, when exposed to pollutant substances. Trees record and incorporate in their log, developed year after year, the impressions of the environment, becoming possible the study of the different environmental changes, including contamination, that have occurred over the life of these trees. The selected species, Tipuana Tipu, of the Leguminosae family, is native of Argentina and Bolivia and was introduced in Brazil as an ornamental plant. It is one of the most common trees in the urban landscaping in Sao Paulo city. The present project has as main objective the determination of the content of potentially toxic elements in samples of growth the tree rings of Tipuana Tipu, previously dated, collected in strategically locations of Sao Paulo, using Synchrotron Radiation Total Reflection X-Ray Fluorescence. Samples were also collected in the Piracicaba (SP), local of little access and small flow traffic. The SR-TXRF analysis was carried out in the X-ray Fluorescence Beamline at the Brazilian Synchrotron Light Source Laboratory, located in Campinas city, Sao Paulo State, Brazil. Some trace elements present concentrations higher than considered as normal in some periods. In this paper the highest value for Pb was 123.54 μg.g{sup -1} considered as threshold value was observed for the period 1998 to 2000 for University of Sao Paulo, Butanta site. For the same period excessive level was also observed for samples collected in Piracicaba city. In Sao Paulo city, sample collected in the campus of University of Sao Paulo (Butanta), showed the highest toxicity, with concentration above the tolerable limit for Ti, Cr and Cu. For the samples collected in Piracicaba city the concentrations of Cr, Ni, Cu, and Pb exceeding the toxicity limits. (author)

  2. EXAFS in total reflection (reflEXAFS) for the study of organometallic Pd(II) thiol complexes based self-assembled monolayers on gold

    International Nuclear Information System (INIS)

    Graphical abstract: The molecular structure and organization of organometallic Pd(II) thiolates SAMs and multilayers on Au/Si(1 1 1) were investigated by reflEXAFS. For SAMs, S-Au bond lengths, Pd-S-Au bond angles and molecular orientations were assessed. Research highlights: → Organometallic Pt(II) thiolates deposited as SAMs and multilayers on gold. → Molecular structure and organization of SAMs and multilayers studied by reflEXAFS. → SAMs S-Au bond lengths, Pd-S-Au bond angles and molecular orientations are assessed. - Abstract: The molecular structure and organization of self-assembled monolayers (SAMs) and multilayer films grafted onto Au/Si(1 1 1) surfaces of mononuclear transition metal dialkynyl bridged Pd(II) complexes trans-[HS-Pd(PBu3)2-SH] (1), trans-[HS-Pd(PBu3)2(-C≡C-C6H5)] (2) and of the binuclear complex trans, trans-[HS-Pd(PBu3)2(-C≡C-C6H4-C6H4-C≡C-Pd(PBu3)2-SH] (3), have been investigated by extended X-ray absorption fine structure spectroscopy in total reflection conditions (reflEXAFS). ReflEXAFS analysis of the data lead to determine the local structure around Pd atoms, assessing the square-planar geometry around the transition metal in the multilayers case, preserved in the monolayer regime. The investigation on the SAMs also provided the assessment of the S-Au bond length and Pd-S-Au bond angle and on the molecular orientation on the gold substrate of the complexes, confirmed by quantum chemical calculations.

  3. Evaluation of Fe and Zn/Cu ratio in serum of patients with sickle cell anemia by total reflection X-ray fluorescence using synchrotron radiation

    International Nuclear Information System (INIS)

    Sickle cell anemia (SCA) is a blood disorder that affects hemoglobin, the protein found in red blood cells that help carry oxygen throughout the body. In this work we have analyzed serum samples from patients with SCA by using total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). The SRTXRF measurements were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo using a polychromatic beam. We have studied forty-three patients aged 18-50 years old, suffering from SCA and Sixty healthy volunteers aged 18-60 years old. It was possible to determine the concentrations of the following elements: P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. Student's t-test was applied in order to check whether the two populations (CG x SCA) had the same mean values. It was observed that elemental concentration of P, Cl, K, Fe, Cu, Zn and Br differed significantly (α = 0.05) between groups of healthy subjects and SCA. The concentrations of K, Fe and Cu in the serum samples of patients with SCA were larger 15%, 120 % and 20 %, respectively, when compared with the CG. On the other hand, the concentrations of P (-20 %), Cl (-6 %), Zn (-25 %) and Br (-22 %) were smaller than the values determined for the control group. The serum level Cu/Zn ratio was significantly higher (60%) in the serum samples of patients with SCA group than the CG. So, the Cu/Zn ratio can be used as an adjuvant index in enhancement for diagnosis of SCA. There are evidences of an association among Fe, Cu, Zn and Cu/Zn in the SCA pathogenesis process. (author)

  4. Evaluation of Fe and Zn/Cu ratio in serum of patients with sickle cell anemia by total reflection X-ray fluorescence using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Canellas, Catarine G.L.; Leitao, Roberta G.; Lopes, Ricardo T., E-mail: catarine@lin.ufrj.b, E-mail: ricardo@lin.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear. Lab. de Instrumentaco Nuclear; Carvalho, Silvia M.F., E-mail: silvia@hemorio.rj.gov.b [State Institute of Hematology Arthur de Siqueira Cavalcanti (HEMORIO), Rio de Janeiro, RJ (Brazil); Bellido, Alfredo Victor B., E-mail: alfredo@ien.gov.b [Federal Fluminense University (UFF), Niteroi, RJ (Brazil). Chemistry Inst.; Anjos, Marcelino J., E-mail: marcelin@lin.ufrj.b [State University of Rio de Janeiro (UERJ), RJ (Brazil). Physics Inst.

    2011-07-01

    Sickle cell anemia (SCA) is a blood disorder that affects hemoglobin, the protein found in red blood cells that help carry oxygen throughout the body. In this work we have analyzed serum samples from patients with SCA by using total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). The SRTXRF measurements were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo using a polychromatic beam. We have studied forty-three patients aged 18-50 years old, suffering from SCA and Sixty healthy volunteers aged 18-60 years old. It was possible to determine the concentrations of the following elements: P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. Student's t-test was applied in order to check whether the two populations (CG x SCA) had the same mean values. It was observed that elemental concentration of P, Cl, K, Fe, Cu, Zn and Br differed significantly ({alpha} = 0.05) between groups of healthy subjects and SCA. The concentrations of K, Fe and Cu in the serum samples of patients with SCA were larger 15%, 120 % and 20 %, respectively, when compared with the CG. On the other hand, the concentrations of P (-20 %), Cl (-6 %), Zn (-25 %) and Br (-22 %) were smaller than the values determined for the control group. The serum level Cu/Zn ratio was significantly higher (60%) in the serum samples of patients with SCA group than the CG. So, the Cu/Zn ratio can be used as an adjuvant index in enhancement for diagnosis of SCA. There are evidences of an association among Fe, Cu, Zn and Cu/Zn in the SCA pathogenesis process. (author)

  5. Stress Wave Reflecting Attenuation to Improve Anti-shock Capacity by Gasket%垫片提高抗冲击能力的应力波衰减机理

    Institute of Scientific and Technical Information of China (English)

    徐蓬朝; 黄惠东; 张龙山; 周平; 许冉

    2012-01-01

    Most of researches on anti-shock for penetrating fuze suggests that elasto-plastic gasket materials can be used because of their properties of cushion and energy-absorption. But the theory of cushion can hardly explain that why the gasket can improve fuze parts anti-shock capacity. In this paper, stress wave attenuating by gasket was regarded as the major factor of anti-shock. The large percentage of stress wave was reflected at fuze-shell/gasket interface. The gasket had few effects on acceleration but significant on attenuating fluctuation of stress wave. The simulation results indicateed that (1) the less of the impedance, the better of attenuation; (2) the thickness of the gaskets had few effects on attenuations (3)multilayer different gaskets were much better.%引信零部件抗高过载冲击,目前大多文献和资料提到用弹塑性垫片材料进行缓冲、吸能,但是缓冲理论并不能解释垫片提高引信零部件耐高过载能力.为此,提出垫片提高引信零部件抗冲击能力的机理主要是应力波反射衰减,即机械滤波.根据应力波在不同界面的反射与透射理论,冲击应力波在通过结构件与垫片的分界面时,因大部分被反射而衰减,垫片提高被保护件抗冲击能力的主要原因不是弹性缓冲,而是机械滤波;垫片对于被保护件质心惯性加速度影响很小,却能显著衰减骑在质心加速度曲线上的应力波,降低二者的合力尖峰,并减少往复振动冲击的破坏.仿真表明:垫片滤波说比缓冲说更合理,并且,波阻抗越小的垫片,机械滤波效果越好;只要远小于有效缓冲厚度,垫片厚度对机械滤波贡献不大;使用不同材料的两层垫片优于同厚度的单一材质垫片,多层更好.

  6. Determination of metals in samples of Cocuy hand craft penca, produced in Lara State, Venezuela, by use of Total Reflection X-Ray Fluorescence

    International Nuclear Information System (INIS)

    Full text: The cocuy is a hydro alcoholic mixture coming from the distillation of fermented juice of agave cocuy. It is originate from Venezuela and it is produced in arid and semi-arid regions of that Country. In the last years, government has been concerned to obtain the legalization of the cocuy produced by peasants from the Municipality Urdaneta. The characterization of the cocuy produced in this municipality is an important contribution for the community and for the health of the consumers. To study the characteristics of the process of cocuy production in that region, it was carried out a census of producers, and a survey was applied in order to obtain information about raw material, process and storage of the cocuy. Samples were taken from different producers, to which it was determined p H, acidity, alcoholic degree, dry extract, refraction index, and content of Cu, Zn, Fe and Pb. The determination of metal in samples of cocuy was carried out by the method of Total Reflection X-Ray Fluorescence. This technique is very appropriate for alcoholic matrices, since effects of matrices are not observed, contrary to the technique of Atomic Absorption, which is the suitable one for the quality standards for this kind of drinks. The method TXRF has the additional advantage of the simultaneous determination with sample volumes of microliters order. The in situ internal standardization (in the reflector) was investigated by use of two methodologies, and the traditional procedure of addition of the internal pattern was compared. The analytic quality of the obtained results for each procedure it was object of analysis and it will be discussed. The concentration of metal Zn, Fe and Pb was near to limit of detection of the technique. The accuracy of the obtained results for Cu was determined by comparison with the technique of Atomic Absorption and it will also be object of discussion. They were found differences between the content of metal and the alcoholic degree, among

  7. Ultrasound transmission attenuation tomography using energy-scaled amplitude ratios

    Science.gov (United States)

    Chen, Ting; Shin, Junseob; Huang, Lianjie

    2016-04-01

    Ultrasound attenuation of breast tumors is related to their types and pathological states, and can be used to detect and characterize breast cancer. Particularly, ultrasound scattering attenuation can infer the margin properties of breast tumors. Ultrasound attenuation tomography quantitatively reconstructs the attenuation properties of the breast. Our synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays records both ultrasound reflection and transmission signals. We develop an ultrasound attenuation tomography method using ultrasound energy-scaled amplitude decays of ultrasound transmission signals and conduct ultrasound attenuation tomography using a known sound-speed model. We apply our ultrasound transmission attenuation tomography method to a breast phantom dataset, and compare the ultrasound attenuation tomography results with conventional beamforming ultrasound images obtained using reflection signals. We show that ultrasound transmission attenuation tomography complements beamforming images in identifying breast lesions.

  8. Reflecting Reflective Practice

    Science.gov (United States)

    Galea, Simone

    2012-01-01

    This paper demystifies reflective practice on teaching by focusing on the idea of reflection itself and how it has been conceived by two philosophers, Plato and Irigaray. It argues that reflective practice has become a standardized method of defining the teacher in teacher education and teacher accreditation systems. It explores how practices of…

  9. IGF-I bioactivity might reflect different aspects of quality of life than total IGF-I in gh-deficient patients during GH treatment

    NARCIS (Netherlands)

    A.J. Varewijck (Aimee); S.W.J. Lamberts (Steven); S.J.C.M.M. Neggers (Bas); L.J. Hofland (Leo); J.A.M.J.L. Janssen (Joseph)

    2013-01-01

    textabstractContext: No relationship has been found between improvement in quality of life (QOL) and total IGF-I during GH therapy. Aim: Our aim was to investigate the relationship between IGF-I bioactivity and QOL in GH-deficient (GHD) patients receiving GH for 12 months. Methods: Of 106 GHD patien

  10. Reflecting reflection in supervision

    DEFF Research Database (Denmark)

    Lystbæk, Christian Tang

    Reflection has moved from the margins to the mainstream in supervision. Notions of reflection have become well established since the late 1980s. These notions have provided useful framing devices to help conceptualize some important processes in guidance and counseling. However, some applications...... associated with reflection and an exploration of alternative conceptions that view reflection within the context of settings which have a more group- and team-based orientation. Drawing on an action research project on health care supervision, the paper questions whether we should reject earlier views...... of reflection, rehabilitate them in order to capture broader connotations or move to new ways of regarding reflection that are more in keeping with not only reflective but also emotive, normative and formative views on supervision. The paper presents a critical perspective on supervision that challenge...

  11. Experimental and theoretical studies on visible light attenuation in water

    CERN Document Server

    Simpson, A; Cho, H J; Liu, H

    2014-01-01

    In this study we describe lab experiments on determining the above water reflectance Rrs coefficient, and the water attenuation coefficient Kd for fresh water. Different types of screens (totally absorbent, gray, etc.) were submerged in water (0-0.6 m) and illuminated from outside. The spectral density of the water leaving radiance was measured for different depths. The results were ran by a code which took into account the geometry of the incident irradiation, the geometry of the screen under water, and boundary conditions at the water surface provided by the radiation transfer theory. From the experimental data and our model we obtain the spectral distribution of the attenuation coefficient for fresh water and compared it with other data in literature. These experiments, performed in the Nonlinear Wave Lab at ERAU# represent just a preliminary calibration of the experimental protocol. More tests with water of different degrees of turbidity, and possibly wave filed at the water surface are in progress and wi...

  12. Total and free insulin-like growth factor I, insulin-like growth factor binding protein 3 and acid-labile subunit reflect clinical activity in acromegaly

    DEFF Research Database (Denmark)

    Sneppen, S B; Lange, Merete Wolder; Pedersen, L M;

    2001-01-01

    insulin-like growth factor binding protein-3 (IGFBP-3) with PV(pos) of 0.69 and 0.71 and PV(neg) of 0.91 and 0.92 respectively. We conclude that free IGF-I is more closely related than total IGF-I to perceived disease activity and is as such useful when evaluating previously treated acromegaly for disease...... activity. Total IGF-I, IGFBP-3 and ALS possess a higher PV(neg) for the clinical disease activity. None of the parameters can at present be claimed to be superior to the others and thus all the measured parameters are recommended to be part of the evaluation of acromegalic patients....

  13. Total and free insulin-like growth factor I, insulin-like growth factor binding protein 3 and acid-labile subunit reflect clinical activity in acromegaly

    DEFF Research Database (Denmark)

    Sneppen, S B; Lange, Merete Wolder; Pedersen, L M;

    2001-01-01

    The aim was to evaluate, markers of disease activity in acromegaly in relation to perceived disease activity. Thirty-seven consecutively treated, acromegalic patients, classified by clinical symptoms as inactive (n=16), slightly active (n=10) and active (n=11), entered the study. When evaluating......-like growth factor binding protein-3 (IGFBP-3) with PV(pos) of 0.69 and 0.71 and PV(neg) of 0.91 and 0.92 respectively. We conclude that free IGF-I is more closely related than total IGF-I to perceived disease activity and is as such useful when evaluating previously treated acromegaly for disease activity...

  14. Design and Fabrication of a Dielectric Total Internal Reflecting Solar Concentrator and Associated Flux Extractor for Extreme High Temperature (2500K) Applications

    Science.gov (United States)

    Soules, Jack A.; Buchele, Donald R.; Castle, Charles H.; Macosko, Robert P.

    1997-01-01

    The Analex Corporation, under contract to the NASA Lewis Research Center (LeRC), Cleveland, Ohio, recently evaluated the feasibility of utilizing refractive secondary concentrators for solar heat receivers operating at temperatures up to 2500K. The feasibility study pointed out a number of significant advantages provided by solid single crystal refractive devices over the more conventional hollow reflective compound parabolic concentrators (CPCs). In addition to the advantages of higher concentration ratio and efficiency, the refractive concentrator, when combined with a flux extractor rod, provides for flux tailoring within the heat receiver cavity. This is a highly desirable, almost mandatory, feature for solar thermal propulsion engine designs presently being considered for NASA and Air Force thermal applications. Following the feasibility evaluation, the NASA-LeRC, NASA-Marshall Space Flight Center (MSFC), and Analex Corporation teamed up to design, fabricate, and test a refractive secondary concentrator/flux extractor system for potential use in the NASA-MSFC "Shooting Star" flight experiment. This paper describes the advantages and technical challenges associated with the design methodologies developed and utilized and the material and fabrication limitations encountered.

  15. Mapping of Total Carbon and Clay Contents in Glacial Till Soil Using On-the-Go Near-Infrared Reflectance Spectroscopy and Partial Least Squares Regression

    Institute of Scientific and Technical Information of China (English)

    SHEN Zhang-Quan; SHAN Ying-Jie; PENG Li; JIANG Yu-Gen

    2013-01-01

    Characterizing spatial variability of soil attributes,using traditional soil sampling and laboratory analysis,is cost prohibitive.The potential benefit of managing soils on a site-specific basis is well established.High variations in glacial till soil render detailed soil mapping difficult with limited number of soil samples.To overcome this problem,this paper demonstrates the feasibility of soil carbon and clay mapping using the newly developed on-the-go near-infrared reflectance spectroscopy (NIRS).Compared with the geostatistics method,the partial least squares regression (PLSR),with NIRS measurements,could yield a more detailed map for both soil carbon and clay.Further,by using independent validation dataset,the accuracy of predicting could be improved significantly for soil clay content and only slightly for soil carbon content.Owing to the complexity of field conditions,more work on data processing and calibration modeling might be necessary for using on-the-go NIRS measurements.

  16. Total Reflection Through Effect of Light in 1D Photonic Crystal%光在一维光子晶体中的全反射贯穿效应

    Institute of Scientific and Technical Information of China (English)

    刘启能

    2011-01-01

    为了研究一维光子晶体中光波的全反射贯穿效应,利用传输矩阵法计算了TE波和TM波在大于全反射角入射一维光子晶体的透射率.在透射波中发现了全反射贯穿效应,得出了全反射贯穿效应随入射角的变化规律、全反射贯穿效应的波长特性以及全反射贯穿效应随介质光学厚度的变化规律.利用波的量子理论和渐逝波的理论对一维光子晶体的全反射贯穿效应作出了理论解释.%The transition matrix method was adopted, and the transmissivity of TE wave and TM wave were analyzed when incident angle greater than full reflection angle, to study the total reflection through effect of light in one-dimensional (1D) photonic crystal. The total reflection through effect was found in the transmission wave. Response curves of the through effect versus incident angle, response curves of the through effect versus wavelength, and response curves of the through effect versus medium thickness were obtained. Total reflection through effect of light in 1D photonic crystal was also explained by the theories of quantum and evanescent wave.

  17. Photonic Crystal Fiber Attenuator

    Institute of Scientific and Technical Information of China (English)

    Joo Beom Eom; Hokyung Kim; Jinchae Kim; Un-Chul Paek; Byeong Ha Lee

    2003-01-01

    We propose a novel fiber attenuator based on photonic crystal fibers. The difference in the modal field diameters of a conventional single mode fiber and a photonic crystal fiber was used. A variable optical attenuator was also achieved by applying macro-bending on the PCF part of the proposed attenuator

  18. The New Progress of XAFS Study at BSRF——Total Reflection XAFS Method%BSRF XAFS的新进展——全反射XAFS实验方法

    Institute of Scientific and Technical Information of China (English)

    谢亚宁; 刘涛; 胡天斗

    2001-01-01

    Total reflection XAFS method is an important aspect in XAFSstudy, and can be applied to the study of surface and interface structure of materials. To develop this experimental system is one of the projects carried out at XAFS station in BSRF. The goniometer for sample, an important device, has been made and the whole experimental system is under commissioning at the present stage. The mechanical structure of the goniometer, the configuration of the experimental system, the scheme for setting up the system and the primary result are described. Also the application for total reflection XAFS and DAFS with this system are briefly discussed in this paper.%开展全反射XAFS研究是BSRFXAFS实验站的发展课题之一.目前关键设备全反射实验样品台已加工完成,正处于安装及系统调试阶段.本文介绍了样品台的结构原理,全反射实验系统的构成、设置调整方案及初步实验结果.此外还讨论了应用该设备可开展的全反射XAFS,DAFS等实验方法.

  19. Use of attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy in direct, non-destructive, and rapid assessment of developmental cotton fibers grown in planta and in culture

    Science.gov (United States)

    Cotton fibers are routinely harvested from cotton plants (in planta), and their end-use qualities depend on their development stages. Cotton fibers are also cultured at controlled laboratory environments, so that cotton researchers can investigate many aspects of experimental protocols in cotton bre...

  20. Lens testing using total internal reflection holography

    Science.gov (United States)

    Hildebrand, Bernard P.

    1976-12-14

    Accurate, rapid and inexpensive testing and inspecting of lens surfaces tugh holographic means requiring no beamsplitters, mirrors or overpower optics, and wherein a hologram formed in accordance with one aspect of the invention contains the entire interferometer and serves as both a master and illuminating source for both concave and convex surfaces to be so tested.

  1. Reflective Teaching

    Science.gov (United States)

    Farrell, Thomas S. C.

    2013-01-01

    Thomas Farrell's "Reflective Teaching" outlines four principles that take teachers from just doing reflection to making it a way of being. Using the four principles, Reflective Practice Is Evidence Based, Reflective Practice Involves Dialogue, Reflective Practice Links Beliefs and Practices, and Reflective Practice Is a Way of Life,…

  2. Attenuation layer for magnetostatic wave (MSW) absorbers

    Science.gov (United States)

    Glass, H. L.; Adkins, L. R.; Stearns, F. S.

    1984-09-01

    A new technique has been developed for the suppression of MSW end reflections which give rise to passband ripple. The basic idea is to provide a thin film of highly attenuating epitaxial material at the ends of a MSW delay line while preserving high quality YIG in the active region of the device. The GGG wafer preparation is a three step process which involves: (1) the growth of the attenuation layer, (2) the removal of this layer from the central region of the wafer and (3) the growth of high quality YIG on the remaining structure. Delay lines using the attenuation layer for end terminations have been evaluated experimentally and compared to devices utilizing other termination methods. The results indicate that the attenuation layer method produces ripple suppression characteristics which are the equal of those obtained with other termination techniques. The advantage of this new method lies in its suitability for large quantity fabrication requirements.

  3. Aspects of flow attenuation performance of retention ponds

    Science.gov (United States)

    Wallis, S. G.; Morgan, C. T.; Heal, K.

    2003-04-01

    was used in all simulations, based on the results of a time step analysis, undertaken to ensure that accurate solutions were being obtained. As expected, the total outflow volume was found to be related only to the total inflow volume and the static storage available at the start of the inflow hydrograph. The peak outflow was found to reduce with increasing static storage and to reduce with decreasing weir angle. All three time delays were found to increase with increasing static storage, which simply reflects the increasing time required for the inflow to occupy the storage available. Decreasing the weir angle increased the peak and centroid time delays but had no effect on the initial time delay. This reflects the control exercised by the weir once outflow begins, and illustrates the role of the dynamic storage (i.e. the temporary storage available above the weir crest elevation). In summary, the flow attenuation performance of the pond was improved (reduced peak outflow and increased time delays) by reducing the weir angle but was worsened by reducing the static storage. Although the nature of these results are entirely predictable, they highlight two key aspects of the long term performance of retention ponds. Firstly, accumulation of sediment will eventually reduce a pond’s ability to attenuate flows and secondly short dry periods between storms adversely affects their attenuation performance. Neither of these features are routinely taken into account during the design of SUDS in Scotland, yet the effect on the receiving water course could be significant. For example, the earlier occurrence of a larger peak outflow (compared to the design condition) could lead to local flooding if it were to coincide with the time of the peak flow in the watercourse. Currently SUDS are designed for individual sites, but, as they become more prevalent, catchment management will need to examine the design and performance of SUDS within the context of the whole catchment.

  4. Microwave attenuation with composite of copper microwires

    Energy Technology Data Exchange (ETDEWEB)

    Gorriti, A.G.; Marin, P. [Instituto de Magnetismo Aplicado, (UCM-ADIF-CSIC) and Departamento de Fisica de Materiales (UCM). P.O. Box 155, Las Rozas, Madrid 28230 (Spain); Cortina, D. [Micromag S.L., Las Rozas, Madrid 28230 (Spain); Hernando, A., E-mail: antonio.hernando@adif.e [Instituto de Magnetismo Aplicado, (UCM-ADIF-CSIC) and Departamento de Fisica de Materiales (UCM). P.O. Box 155, Las Rozas, Madrid 28230 (Spain); Micromag S.L., Las Rozas, Madrid 28230 (Spain)

    2010-05-15

    It is shown that copper microwires composite media attenuates microwave reflection of metallic surfaces. We show how the distance to the metallic surface, as well as the length and volume fraction of microwires, determine the frequency of maximum absorption and the return loss level. Furthermore, we were able to fit the experimental results with a theoretical model based on Maxwell-Garnett mixing formula.

  5. Quantitative analysis of X-band weather radar attenuation correction accuracy

    Directory of Open Access Journals (Sweden)

    A. Berne

    2006-01-01

    Full Text Available At short wavelengths, especially C-, X-, and K-band, weather radar signals are attenuated by the precipitation along their paths. This constitutes a major source of error for radar rainfall estimation, in particular for intense precipitation. A recently developed stochastic simulator of range profiles of raindrop size distributions (DSD provides a controlled experiment framework to investigate the accuracy and robustness of attenuation correction algorithms. The work presented here focuses on the quantification of the influence of uncertainties concerning radar calibration, the parameterization of power law relations between the integral variables (radar reflectivity Z and specific attenuation k, and total path integrated attenuation (PIA estimates at X-band. The analysis concerns single frequency, incoherent and non-polarimetric radar systems. Two attenuation correction algorithms, based on a forward and a backward implementation respectively, are studied. From DSD range profiles, the corresponding profiles of integral radar variables are derived. Using a Monte Carlo approach, the accuracy and robustness of the two algorithms are quantified for the different sources of error previously mentioned. This framework of realistic DSD variability provides a robust way to confirm that, under realistic assumptions concerning the PIA estimation uncertainty, the forward algorithm outperforms the backward algorithm for PIA values below 10 dB.

  6. Mechanisms of geometrical seismic attenuation

    Directory of Open Access Journals (Sweden)

    Igor B. Morozov

    2011-07-01

    Full Text Available In several recent reports, we have explained the frequency dependence of the apparent seismic quality-factor (Q observed in many studies according to the effects of geometrical attenuation, which was defined as the zero-frequency limit of the temporal attenuation coefficient. In particular, geometrical attenuation was found to be positive for most waves traveling within the lithosphere. Here, we present three theoretical models that illustrate the origin of this geometrical attenuation, and we investigate the causes of its preferential positive values. In addition, we discuss the physical basis and limitations of both the conventional and new attenuation models. For waves in media with slowly varying properties, geometrical attenuation is caused by variations in the wavefront curvature, which can be both positive (for defocusing and negative (for focusing. In media with velocity/density contrasts, incoherent reflectivity leads to geometrical-attenuation coefficients which are proportional to the mean squared reflectivity and are always positive. For «coherent» reflectivity, the geometrical attenuation is approximately zero, and the attenuation process can be described according to the concept of «scattering Q». However, the true meaning of this parameter is in describing the mean reflectivity within the medium, and not that of the traditional resonator quality factor known in mechanics. The general conclusion from these models is that non-zero and often positive levels of geometrical attenuation are common in realistic, heterogeneous media, both observationally and theoretically. When transformed into the conventional Q-factor form, this positive geometrical attenuation leads to Q values that quickly increase with frequency. These predictions show that the positive frequency-dependent Q observed in many datasets might represent artifacts of the transformations of the attenuation coefficients into Q.

  1. X-Ray Form Factor, Attenuation and Scattering Tables

    Science.gov (United States)

    SRD 66 X-Ray Form Factor, Attenuation and Scattering Tables (Web, free access)   This database collects tables and graphs of the form factors, the photoabsorption cross section, and the total attenuation coefficient for any element (Z <= 92).

  2. Planetary Ices Attenuation Properties

    Science.gov (United States)

    McCarthy, Christine; Castillo-Rogez, Julie C.

    In this chapter, we review the topic of energy dissipation in the context of icy satellites experiencing tidal forcing. We describe the physics of mechanical dissipation, also known as attenuation, in polycrystalline ice and discuss the history of laboratory methods used to measure and understand it. Because many factors - such as microstructure, composition and defect state - can influence rheological behavior, we review what is known about the mechanisms responsible for attenuation in ice and what can be inferred from the properties of rocks, metals and ceramics. Since attenuation measured in the laboratory must be carefully scaled to geologic time and to planetary conditions in order to provide realistic extrapolation, we discuss various mechanical models that have been used, with varying degrees of success, to describe attenuation as a function of forcing frequency and temperature. We review the literature in which these models have been used to describe dissipation in the moons of Jupiter and Saturn. Finally, we address gaps in our present knowledge of planetary ice attenuation and provide suggestions for future inquiry.

  3. Total algorithms

    NARCIS (Netherlands)

    Tel, G.

    1993-01-01

    We define the notion of total algorithms for networks of processes. A total algorithm enforces that a "decision" is taken by a subset of the processes, and that participation of all processes is required to reach this decision. Total algorithms are an important building block in the design of distri

  4. Estimating Total Nitrogen Content in Wetland Vegetation Based on Measured Reflectance Spectra%基于地面实测光谱的湿地植物全氮含量估算研究

    Institute of Scientific and Technical Information of China (English)

    刘克; 赵文吉; 郭逍宇; 王翊虹; 孙永华; 苗茜

    2012-01-01

    More and more urban wetlands have been supplied with reclaimed water. And monitoring the growth condition of large-area wetland vegetation is playing a very important role in wetland restoration and reconstructioa Recently, remote sensing technology has become an important tool for vegetation growth monitoring. The South Wetland in the Olympic Park, a typical wetland using reused water, was selected as the research area. The leaf reflectance spectra and were acquired for the main wetland plants reed (Phragmites australis) and cattail (Typha angustifolia) with an ASD FieldSpec 3 spectrometer (350~ 2 500 nm). The total nitrogen (TN) content of leaf samples was determined by Kjeldahl method subsequently. The research established univariate models involving simple ratio spectral index (SR) model and normalized difference spectral index (ND) model, as well as multivariate models including stepwise multiple linear regression (SMLR) model and partial least squares regression (PLSR) model. Moreover, the accuracy of all the models was tested through cross-validated coefficient of determination (Rcv) and cross-validated root mean square error (RMSEcv). The results showed that (1) comparing different types of wetland plants, the accuracy of all established prediction models using Phragmites australis reflectance spectra was higher than that u-sing Typha angustifolia reflectance spectra. (2) compared with univariate techniques, multivariate regressions improved the estimation of TN concentration in leaves. (3) among the various investigated models, the accuracy of PLSR model was the highest (Rcv = 0. 80, RMSEcv = 0. 24). PLSR provided the most useful explorative tool for unraveling the relationship between spectral reflectance and TN consistence of leaves. The result would not only provide a scientific basis for remote sensing retrieval of biochemical variables of wetland vegetation, but also provide a strong scientific basis for the monitoring and management of urban wetlands

  5. Frequency Dependent Attenuation Revisited

    CERN Document Server

    Richard, Kowar; Xavier, Bonnefond

    2009-01-01

    The work is inspired by thermo-and photoacoustic imaging, where recent efforts are devoted to take into account attenuation and varying wave speed parameters. In this paper we study causal equations describing propagation of attenuated pressure waves. We review standard models like frequency power laws and and the thermo-viscous equation. The lack of causality of standard models in the parameter range relevant for photoacoustic imaging requires to derive novel equations. The main ingredients for deriving causal equations are the Kramers-Kronig relation and the mathematical concept of linear system theory. The theoretical results of this work are underpined by numerical experiments.

  6. Reflected Glory

    Science.gov (United States)

    2011-02-01

    HD 38563B, are the main powerhouses behind Messier 78. However, the nebula is home to many more stars, including a collection of about 45 low mass, young stars (less than 10 million years old) in which the cores are still too cool for hydrogen fusion to start, known as T Tauri stars. Studying T Tauri stars is important for understanding the early stages of star formation and how planetary systems are created. Remarkably, this complex of nebulae has also changed significantly in the last ten years. In February 2004 the experienced amateur observer Jay McNeil took an image of this region with a 75 mm telescope and was surprised to see a bright nebula - the prominent fan shaped feature near the bottom of this picture - where nothing was seen on most earlier images. This object is now known as McNeil's Nebula and it appears to be a highly variable reflection nebula around a young star. This colour picture was created from many monochrome exposures taken through blue, yellow/green and red filters, supplemented by exposures through an H-alpha filter that shows light from glowing hydrogen gas. The total exposure times were 9, 9, 17.5 and 15.5 minutes per filter, respectively. Notes [1] Igor Chekalin from Russia uncovered the raw data for this image of Messier 78 in ESO's archives in the competition Hidden Treasures (eso1102). He processed the raw data with great skill, claiming first prize in the contest for his final image (Flickr link). ESO's team of in-house image processing experts then independently processed the raw data at full resolution to produce the image shown here. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an

  7. Elemental analysis of human amniotic fluid and placenta by total-reflection X-ray fluorescence and energy-dispersive X-ray fluorescence: child weight and maternal age dependence

    Science.gov (United States)

    Carvalho, M. L.; Custódio, P. J.; Reus, U.; Prange, A.

    2001-11-01

    This work is an attempt to evaluate the possible influence of the mother's age in trace element concentrations in human amniotic fluid and placenta and whether these concentrations are correlated to the weight of the newborn infants. Total-reflection X-ray fluorescence (TXRF) was used to analyze 16 amniotic fluid samples, and the placenta samples were analyzed by energy dispersive X-ray fluorescence (EDXRF). The whole samples were collected during delivery from healthy mothers and healthy infants and full-term pregnancies. According to the age of the mother, three different groups were considered: 20-25, 25-30 and 30-40 years old. Only two mothers were aged more than 35 years. The weight of the infants ranged from 2.56 to 4.05 kg and three groups were also considered: 2.5-3, 3-3.5 and 3.5-4 kg. The organic matrix of the amniotic fluid samples was removed by treatment with HNO 3 followed by oxygen plasma ashing. Yttrium was used as the internal standard for TXRF analysis. Placenta samples were lyophilized and analyzed by EDXRF without any chemical treatment. Very low levels of Ni and Sr were found in the amniotic fluid samples, and were independent of the age of the mother and weight of the child. Cr, Mn, Se and Pb were at the level of the detection limit. Zn, considered one of the key elements in neonatal health, was not significantly different in the samples analyzed; however, it was weakly related to birth weigh. The concentrations obtained ranged from 0.11 to 0.92 mg/l and 30 to 65 μg/g in amniotic fluid and placenta, respectively. The only two elements which seemed to be significantly correlated with mother's age and newborn weight were Ca and Fe for both types of sample: Ca levels were increased in heavier children and older mothers; however, Fe increased with increasing maternal age, but decreased for heavier babies. The same conclusions were obtained for placenta and amniotic fluid samples. Cu is closely associated with Fe in its function in the organism

  8. Quantifying Reflection

    DEFF Research Database (Denmark)

    Alcock, Gordon Lindsay

    2013-01-01

    ´ These are all based on Blooms taxonomy and levels of competence and form a major part of individual student and group learning portfolios. Key Words :Project-Based learning, Reflective Portfolios, Self assessment, Defining learning gains, Developing learning strategies , Reflections on and for learning....... It contrasts the students’ self-assessment in a range of ‘product’ skills such as Revit, Structural Design, Mathematics of construction, Technical Installations; as well as ‘process’ competencies such as ‘Working in a team’, Sharing knowledge, Maintaining a portfolio and Reflecting ON learning and FOR learning......This paper documents 1st semester student reflections on “learning to learn” in a team-based PBL environment with quantitative and qualitative student reflective feedback on the learning gains of 60 Architectural Technology and Construction Management students at VIA University College, Denmark...

  9. Use of borehole radar reflection logging to monitor steam-enhanced remediation in fractured limestone-results of numerical modelling and a field experiment

    Science.gov (United States)

    Gregoire, C.; Joesten, P.K.; Lane, J.W.

    2006-01-01

    Ground penetrating radar is an efficient geophysical method for the detection and location of fractures and fracture zones in electrically resistive rocks. In this study, the use of down-hole (borehole) radar reflection logs to monitor the injection of steam in fractured rocks was tested as part of a field-scale, steam-enhanced remediation pilot study conducted at a fractured limestone quarry contaminated with chlorinated hydrocarbons at the former Loring Air Force Base, Limestone, Maine, USA. In support of the pilot study, borehole radar reflection logs were collected three times (before, during, and near the end of steam injection) using broadband 100 MHz electric dipole antennas. Numerical modelling was performed to predict the effect of heating on radar-frequency electromagnetic (EM) wave velocity, attenuation, and fracture reflectivity. The modelling results indicate that EM wave velocity and attenuation change substantially if heating increases the electrical conductivity of the limestone matrix. Furthermore, the net effect of heat-induced variations in fracture-fluid dielectric properties on average medium velocity is insignificant because the expected total fracture porosity is low. In contrast, changes in fracture fluid electrical conductivity can have a significant effect on EM wave attenuation and fracture reflectivity. Total replacement of water by steam in a fracture decreases fracture reflectivity of a factor of 10 and induces a change in reflected wave polarity. Based on the numerical modelling results, a reflection amplitude analysis method was developed to delineate fractures where steam has displaced water. Radar reflection logs collected during the three acquisition periods were analysed in the frequency domain to determine if steam had replaced water in the fractures (after normalizing the logs to compensate for differences in antenna performance between logging runs). Analysis of the radar reflection logs from a borehole where the temperature

  10. Inspiring Reflections

    DEFF Research Database (Denmark)

    Muchie, Mammo

    2011-01-01

    A numberof Chris Freeman's colleagues were asked to reflect on what they thought describes his life and work in a few words. Some of the colleagues replied including former SPRU students that were taught or supervised by Chris Freeman. Their views on what they thought were Chris Freeman's defining...... but also social exclusion, equity and social justice....

  11. Estimation of compressional seismic wave attenuation of carbonate rocks in Abu Dhabi, United Arab Emirates

    Science.gov (United States)

    Bouchaala, Fateh; Ali, Mohammed Y.; Farid, Asam

    2014-07-01

    The subsurface geology of Abu Dhabi in the United Arab Emirates is primarily composed of carbonate rocks. Such media are known to be highly heterogeneous. Very few studies have attempted to estimate attenuation in carbonate rocks. In Abu Dhabi no attenuation profile has been published. This study provides the first seismic wave attenuation profiles in Abu Dhabi using dense array of VSP data. We estimated three attenuation profiles: the apparent, the scattering, and the intrinsic attenuations. The apparent attenuation profile was computed using amplitude decay and spectral-ratio methods. The scattering attenuation profile was estimated using a generalized reflection-transmission matrix forward model. It is usually estimated from the sonic log, but to be more consistent with the apparent attenuation, we succeeded in this paper to estimate it from the VSP data. We subtracted the scattering attenuation from the apparent attenuation to deduce the intrinsic attenuation. The results of the study indicate that the scattering attenuation is significant compared to the published studies that are mainly based on clastic rocks. The high scattering attenuation can reach up to 0.02. It can be explained by the strong heterogeneity of the carbonate rocks. This study demonstrates that the Simsima and Rus Formations have considerable scattering and intrinsic attenuations. These formations are considered aquifers in Abu Dhabi; we therefore interpreted this high intrinsic attenuation zones to be due to the heterogeneity and to the fluids contained in these formations. The Umm-Er-Radhuma Formation is a more homogenous formation with limited aquifer potential. Hence, scattering and intrinsic attenuations of the Umm-Er-Radhuma Formation are low.

  12. Monte Carlo simulation of diffuse attenuation coefficient in presence of non uniform profiles

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Desai, R.G.P.; Desa, B.A.E.

    This paper presents a Monte Carlo simulation of the vertical depth structure of the downward attenuation coefficient (K sub(d)), and the irradiance reflectance (R) for a given profile of chlorophyll. The results are in quantitaive agreement...

  13. Comparison between ATR-IR, Raman, concatenated ATR-IR and Raman spectroscopy for the determination of total antioxidant capacity and total phenolic content of Chinese rice wine.

    Science.gov (United States)

    Wu, Zhengzong; Xu, Enbo; Long, Jie; Pan, Xiaowei; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

    2016-03-01

    The application of attenuated total reflectance infrared spectroscopy (ATR-IR), Raman spectroscopy (RS) and combination of ATR-IR and RS for measurements of total antioxidant capacity (TAC) and total phenolic content (TPC) of Chinese rice wine (CRW) were investigated in this study. Synergy interval partial least-squares (SiPLS), support vector machine (SVM) and principal component analysis (PCA) were applied to process the merged data from two individual instruments. It was observed that the performances of models based on the RS spectra were better than those based on the ATR-IR spectra. In addition, SVM models based on the efficient information extracted from ATR-IR and RS spectra were superior to PLS models based on the same information and PLS models based on ATR-IR or RS spectra. The overall results demonstrated that integrating ATR-IR and RS was possible and could improve the prediction accuracy of TAC and TPC in CRWs.

  14. Total Thyroidectomy

    Directory of Open Access Journals (Sweden)

    Lopez Moris E

    2016-06-01

    Full Text Available Total thyroidectomy is a surgery that removes all the thyroid tissue from the patient. The suspect of cancer in a thyroid nodule is the most frequent indication and it is presume when previous fine needle puncture is positive or a goiter has significant volume increase or symptomes. Less frequent indications are hyperthyroidism when it is refractory to treatment with Iodine 131 or it is contraindicated, and in cases of symptomatic thyroiditis. The thyroid gland has an important anatomic relation whith the inferior laryngeal nerve and the parathyroid glands, for this reason it is imperative to perform extremely meticulous dissection to recognize each one of these elements and ensure their preservation. It is also essential to maintain strict hemostasis, in order to avoid any postoperative bleeding that could lead to a suffocating neck hematoma, feared complication that represents a surgical emergency and endangers the patient’s life.It is essential to run a formal technique, without skipping steps, and maintain prudence and patience that should rule any surgical act.

  15. On Reflection

    DEFF Research Database (Denmark)

    Blasco, Maribel

    2012-01-01

    This article explores how the concept of reflexivity is used in intercultural education. Reflexivity is often presented as a key learning goal in acquiring intercultural competence (ICC). Yet, reflexivity can be defined in different ways, and take different forms across time and space, depending...... on the concepts of selfhood that prevail and how notions of difference are constructed. First, I discuss how the dominant usages of reflexivity in intercultural education reflect and reproduce a Cartesian view of the self that shapes how ICC is conceptualized and taught. I discuss three assumptions that this view...... in designing learning objectives in intercultural education and in devising ways to attain them. Greater attention is also needed in intercultural education to the ways in which selfhood, and hence also reflexivity and constructions of difference, differ across space and time....

  16. Heat radiative characteristics of ultra-attenuated materials

    Institute of Scientific and Technical Information of China (English)

    Dehong Xia; Yonghong Wu

    2004-01-01

    From the microstructure of heat radiation, the interaction between the incident heat radiative wave and the electromagnetism syntonic wave is analyzed to reveal the emission, absorption, transmission and reflection mechanisms of the incident heat radiative wave in materials. Based on Lorentz dispersion theory, the effect of optical parameters on heat radiative characteristics is also analyzed. The method of ultra-attenuation and nanocrystallization improving the heat radiative characteristics of the material and the emissivity dispersion of the ultra-attenuated materials are brought to light.

  17. Seismic attenuation in fractured media

    International Nuclear Information System (INIS)

    The prime objective of this paper is to quantitatively estimate seismic attenuation caused by fractures with different physical parameters. In seismic wave simulation, the fractured media are treated as the anisotropic media and fractures are represented by frequency-dependent elastic constants. Based on numerical experiments with three different parameters, namely viscosity, porosity and the Lamé parameters, this paper has the following observations. First, seismic attenuation is not affected by the viscosity within fractures, although it increases with the increase of porosity and decreases with the increase of the Lamé parameters within fractures. Among the latter two parameters, seismic attenuation is more sensitive to the Lamé parameters than to the porosity. Second, for the attenuation anisotropy, low frequencies have more anisotropic effect than high frequencies. For example, a 50 Hz wavefield has the strongest anisotropy effect if compared to 100 and 150 Hz wavefields. The attenuation anisotropy for low frequency (say 50 Hz) is more sensitive to the viscosity than the porosity and the Lamé parameters have the weakest effect among these three parameters. These observations suggest that low-frequency seismic attenuation, and especially the attenuation anisotropy in low frequency, would have great potential for fluid discrimination within fractured media. (paper)

  18. Studies of Scattering, Reflectivity, and Transmitivity in WBAN Channel: Feasibility of Using UWB

    Directory of Open Access Journals (Sweden)

    Md. Humaun Kabir

    2010-06-01

    Full Text Available The Wireless Personal Area Network (WPAN is one of the fledging paradigms that the next generation of wireless systems is sprouting towards. Among them, a more specific category is the Wireless Body Area Network (WBAN used for health monitoring. On the other hand, Ultra-Wideband (UWB comes with a number of desirable features at the physical layer for wireless communications. One big challenge in adoption of UWB in WBAN is the fact that signals get attenuated exponentially. Due to the intrinsic structural complexity in human body, electromagnetic waves show a profound variation during propagation through it. The reflection and transmission coefficients of human body are highly dependent upon the dielectric constants as well as upon the frequency. The difference in structural materials such as fat, muscles and blood essentially makes electromagnetic wave attenuation to be different along the way. Thus, a complete characterization of body channel is a challenging task. The connection between attenuation and frequency of the signal makes the investigation of UWB in WBAN an interesting proposition. In this paper, we study analytically the impact of body channels on electromagnetic signal propagation with reference to UWB. In the process, scattering, reflectivity and transmitivity have been addressed with analysis of approximate layer-wise modeling, and with numerical depictions. Pulses with Gaussian profile have been employed in our analysis. It shows that, under reasonable practical approximations, the human body channel can be modeled in layers so as to have the effects of total reflections or total transmissions in certain frequency bands. This could help decide such design issues as antenna characteristics of implant devices for WBAN employing UWB.

  19. The new approach of polarimetric attenuation correction for improving radar quantitative precipitation estimation(QPE)

    Science.gov (United States)

    Gu, Ji-Young; Suk, Mi-Kyung; Nam, Kyung-Yeub; Ko, Jeong-Seok; Ryzhkov, Alexander

    2016-04-01

    To obtain high-quality radar quantitative precipitation estimation data, reliable radar calibration and efficient attenuation correction are very important. Because microwave radiation at shorter wavelength experiences strong attenuation in precipitation, accounting for this attenuation is the essential work at shorter wavelength radar. In this study, the performance of different attenuation/differential attenuation correction schemes at C band is tested for two strong rain events which occurred in central Oklahoma. And also, a new attenuation correction scheme (combination of self-consistency and hot-spot concept methodology) that separates relative contributions of strong convective cells and the rest of the storm to the path-integrated total and differential attenuation is among the algorithms explored. A quantitative use of weather radar measurement such as rainfall estimation relies on the reliable attenuation correction. We examined the impact of attenuation correction on estimates of rainfall in heavy rain events by using cross-checking with S-band radar measurements which are much less affected by attenuation and compared the storm rain totals obtained from the corrected Z and KDP and rain gages in these cases. This new approach can be utilized at shorter wavelength radars efficiently. Therefore, it is very useful to Weather Radar Center of Korea Meteorological Administration preparing X-band research dual Pol radar network.

  20. An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data

    Science.gov (United States)

    Jordan, T. M.; Bamber, J. L.; Williams, C. N.; Paden, J. D.; Siegert, M. J.; Huybrechts, P.; Gagliardini, O.; Gillet-Chaulet, F.

    2016-07-01

    Radar inference of the bulk properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. On the scale of an ice sheet, unambiguous determination of basal reflection is primarily limited by uncertainty in the englacial attenuation of the radio wave, which is an Arrhenius function of temperature. Existing bed-returned power algorithms for deriving attenuation assume that the attenuation rate is regionally constant, which is not feasible at an ice-sheet-wide scale. Here we introduce a new semi-empirical framework for deriving englacial attenuation, and, to demonstrate its efficacy, we apply it to the Greenland Ice Sheet. A central feature is the use of a prior Arrhenius temperature model to estimate the spatial variation in englacial attenuation as a first guess input for the radar algorithm. We demonstrate regions of solution convergence for two input temperature fields and for independently analysed field campaigns. The coverage achieved is a trade-off with uncertainty and we propose that the algorithm can be "tuned" for discrimination of basal melt (attenuation loss uncertainty ˜ 5 dB). This is supported by our physically realistic ( ˜ 20 dB) range for the basal reflection coefficient. Finally, we show that the attenuation solution can be used to predict the temperature bias of thermomechanical ice sheet models and is in agreement with known model temperature biases at the Dye 3 ice core.

  1. A Reflective Look at Reflecting Teams

    Science.gov (United States)

    Pender, Rebecca L.; Stinchfield, Tracy

    2012-01-01

    This article reviewed existing literature and research on the reflecting team process. There is a dearth of empirical research that explores the reflecting team process and the outcome of counseling that uses reflecting teams. Implications of using reflecting teams for counselors, counselor educators, and clients will be discussed. A call for…

  2. Utilization of ilmenite/epoxy composite for neutrons and gamma rays attenuation

    International Nuclear Information System (INIS)

    This work deals with the study of ilmenite/epoxy composite as an injecting mortar for cracks developed in biological concrete shields, as well as, neutrons and gamma rays attenuation. Effects of the particle size on the mechanical strengths have been studied for epoxy resin filled with crushed ilmenite with different maximum particle sizes ranging from 32 to 500 μm. Thermal neutrons and gamma rays attenuation in ilmenite/epoxy composites with 75 and 80 wt.% of ilmenite concentration have been investigated. The total mass attenuation coefficients μ/ρ (cm2 g-1) of gamma ray for five ilmenite/epoxy composites have been calculated using the XCOM program (version 3.1) at energies from 10 keV to 100 MeV. Also, the total mass attenuation coefficients (μ/ρ) have estimated based on the measured total linear attenuation coefficients (μ) and compared with the calculated results where, a reasonable agreement was found

  3. Hollow optical-fiber based infrared spectroscopy for measurement of blood glucose level by using multi-reflection prism.

    Science.gov (United States)

    Kino, Saiko; Omori, Suguru; Katagiri, Takashi; Matsuura, Yuji

    2016-02-01

    A mid-infrared attenuated total reflection (ATR) spectroscopy system employing hollow optical fibers and a trapezoidal multi-reflection ATR prism has been developed to measure blood glucose levels. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. An analysis of in vivo measurements of human inner lip mucosa revealed clear signatures of glucose in the difference spectra between ones taken during the fasting state and ones taken after ingestion of glucose solutions. A calibration plot based on the absorption peak at 1155 cm(-1) that originates from the pyranose ring structure of glucose gave measurement errors less than 20%. PMID:26977373

  4. Blood glucose measurement in vivo using hollow-fiber based, mid-infrared ATR probe with multi-reflection prism

    Science.gov (United States)

    Kino, Saiko; Omori, Suguru; Matsuura, Yuji

    2016-03-01

    An attenuated-total-reflection (ATR), mid-infrared spectroscopy system that consists of hollow optical fibers, a trapezoidal multi-reflection ATR prism, and a conventional FT-IR spectrometer has been developed to measure blood glucose levels. Owing to the low transmission loss and high flexibility of the hollow-optical fiber, the system can measure any sites of the human body where blood capillaries are close to the surface of mucosa, such as inner lips. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. The results of in-vivo measurement of human inner lips showed the feasibility of the proposed system, and the measurement errors were within 20%.

  5. Hollow optical-fiber based infrared spectroscopy for measurement of blood glucose level by using multi-reflection prism.

    Science.gov (United States)

    Kino, Saiko; Omori, Suguru; Katagiri, Takashi; Matsuura, Yuji

    2016-02-01

    A mid-infrared attenuated total reflection (ATR) spectroscopy system employing hollow optical fibers and a trapezoidal multi-reflection ATR prism has been developed to measure blood glucose levels. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. An analysis of in vivo measurements of human inner lip mucosa revealed clear signatures of glucose in the difference spectra between ones taken during the fasting state and ones taken after ingestion of glucose solutions. A calibration plot based on the absorption peak at 1155 cm(-1) that originates from the pyranose ring structure of glucose gave measurement errors less than 20%.

  6. Totaleindruck o impresión total: La Telésfora de Aquinas Ried como proyecto político, creación literario-musical, reflejo personal y encuentro con el otro Totaleindruck or total impression: Aquinas Ried's Telésfora as a Political Project, a Literary and Musical Creation, a Personal Reflection and an Encounter with the Others

    Directory of Open Access Journals (Sweden)

    José Manuel Izquierdo König

    2011-06-01

    Full Text Available La Telésfora (1847, ópera en tres actos de Aquinas Ried, se ha instalado desde los trabajos de Eugenio Pereira Salas, como el primer drama lírico escrito en suelo chileno. El presente ensayo busca discutir esta consideración a partir del único elemento que le sobrevive: su libreto. A partir del mismo, la obra de Ried se revela como un proyecto político concreto, un reflejo personal de sus ideas y su encuentro con los chilenos, alemanes y mapuches de mediados del siglo XIX. En este sentido, la figura de Aquinas Ried se amplía a todo un espectro de la vida musical y cosmopolita de la ciudad de Valparaíso y los inmigrantes en Chile.Telésfora (1847 is a three-act opera written by Aquinas Ried. Since the epoch of the Chilean music historian Eugenio Pereira Salas this work has been considered as the first lyrical drama composed in the Chilean territory after the independence. The following essay discusses this point in depth on the basis of the libretto, which is the only element of this opera that has remained. The libretto reveals a concrete political project as well as a personal reflection on Ried's ideas along with his encounter with Chileans, Germans and indigenous people of the nineteenth century. In this regard, the figure of Aquinas Ried reaches a wider spectrum encompassing the musical and cosmopolitan life of the city of Valparaiso and the immigrants in 19th-century Chile.

  7. Gamma and neutron attenuation behaviours of boron carbide–silicon carbide composites

    International Nuclear Information System (INIS)

    Highlights: • Gamma and neutron attenuation behaviours of B4C–SiC composites were investigated. • Increasing SiC ratio increases gamma attenuation behaviour of the B4C–SiC composites. • Increasing SiC ratio decrease attenuation behaviour of the B4C–SiC composites. • HVT values of the B4C–SiC composites were calculated for Cs-137, Co-60 and Pu–Be sources. • Experimental mass attenuation coefficient are compatible with theoretical (XCOM) values. - Abstract: In this study, the gamma and neutron attenuation behaviors of pure boron carbide and boron carbide–silicon carbide composites which include three different silicon carbide ratios (20%, 30%, and 40%) by volume were investigated against Cs-137, Co-60 gamma radioisotope sources and Pu–Be neutron source. Transmission technique was used in the experiments to investigate the gamma and neutron attenuation properties of the materials. Linear and mass attenuation coefficients of the samples were determined for 0.662 (Cs-137) and 1.25 MeV (Co-60) energetic gamma rays. In addition the total macroscopic cross-sections (∑T) were calculated for the materials against Pu–Be neutron source. Theoretical mass attenuation coefficients were calculated from XCOM computer code. The experimental and theoretical mass attenuation coefficients were compared and evaluated with each other. In addition half value thickness (HVT) calculations were carried out by using linear attenuation coefficients and total macroscopic cross-sections. The results showed that increasing silicon carbide ratio decreases HVTs against Cs-137 and Co-60 gamma radioisotope sources whereas increases HVTs against Pu–Be neutron source. The mass attenuation coefficients were compatible with the theoretical (XCOM) values. Increasing silicon carbide ratio in boron carbide–silicon carbide composites causes higher gamma attenuation and lower neutron attenuation values

  8. Estimation of Water Vapour Attenuation And Rain Attenuation

    Directory of Open Access Journals (Sweden)

    K.Kalyana Srinivas

    2015-04-01

    Full Text Available Attenuation due to and water vapour and rain can severely degrade the radio wave propagation at centimeter or millimeter wavelengths. It restricts the path length of radio communication systems and limits the use of higher frequencies for line-of-sight microwave links and satellite communications. The attenuation will pose a greater problem to communication as the frequency of occurrence of heavy rain increases.In a tropical region, like Malaysia, where excessive rainfall is a common phenomenon throughout the year, the knowledge of the rain attenuation at the frequency of operation is extremely required for the design of a reliable terrestrial and earth space communication link at a particular location.

  9. The attenuation and the attenuators: strategies and tactics

    Directory of Open Access Journals (Sweden)

    Antonio Briz

    2013-12-01

    Full Text Available This work is inscribed in a research project (ES.POR.ATENUAÇÃO that seeks to analyze and explain the attenuator activity in different regional varieties of Spanish and Portuguese, in order to perform, subsequently, different contrastive intralinguistic and interlinguistic studies. In this article, we explain some of the theoretical and methodological principles on which are based the qualitative and quantitative analysis. And especially, we will refer to the concept of attenuation (Briz 1995, 2002, 2003, 2005, 2007a, 2012.

  10. Photoacoustic Imaging Taking into Account Attenuation

    CERN Document Server

    Kowar, Richard

    2010-01-01

    First, we review existing attenuation models and discuss their causality properties, which we believe to be essential for algorithms for inversion with attenuated data. Then, we survey causality properties of common attenuation models. We also derive integro-differential equations which the attenuated waves are satisfying. In addition we discuss the ill--conditionness of the inverse problem for calculating the unattenuated wave from the attenuated one.

  11. X-ray total reflection mirrors for coherent illumination

    CERN Document Server

    Ishikawa, T; Yabashi, M; Souvorov, A; Yamauchi, K; Yamamura, K; Mimura, H; Saito, A; Mori, Y

    2002-01-01

    X-ray mirrors for coherent illumination demand much higher surface quality than is achievable with the conventional polishing techniques. Plasma chemical vaporization machining (CVM) and elastic emission machining (EEM) have been applied for x-ray mirror manufacturing. Figure error of a flat silicon single crystal mirrors made with CVM+EEM process was reduced to 2.0 nm peak-to-valley and 0.2 nm RMS. The machining process was also applied to make elliptical mirrors. One-dimensional focusing with a single elliptical mirror showed diffraction-limited properties with the focal width of 200 nm. Two-dimensional focusing with Kirkpatric-Baez configuration gave a focal spot size of 200 nm x 200 nm. (author)

  12. Guiding light by and beyond the total internal reflection mechanism

    NARCIS (Netherlands)

    Uranus, Henri Putra

    2005-01-01

    This thesis reports a series of techniques the author has developed to model various waveguiding structures, including the conventional planar and channel waveguides working by, and the advanced structures working beyond the TIR mechanism. Hence, this thesis contains both the methods and their appli

  13. Sound attenuation in magnetorheological fluids

    Science.gov (United States)

    Rodríguez-López, J.; Elvira, L.; Resa, P.; Montero de Espinosa, F.

    2013-02-01

    In this work, the attenuation of ultrasonic elastic waves propagating through magnetorheological (MR) fluids is analysed as a function of the particle volume fraction and the magnetic field intensity. Non-commercial MR fluids made with iron ferromagnetic particles and two different solvents (an olive oil based solution and an Araldite-epoxy) were used. Particle volume fractions of up to 0.25 were analysed. It is shown that the attenuation of sound depends strongly on the solvent used and the volume fraction. The influence of a magnetic field up to 212 mT was studied and it was found that the sound attenuation increases with the magnetic intensity until saturation is reached. A hysteretic effect is evident once the magnetic field is removed.

  14. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.;

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc biased...... at different points in the current-voltage characteristic. Both numerical calculations based on the Tien-Gordon theory and 70-GHz microwave experiments have confirmed the wide dynamic range (more than 15-dB attenuation for one stage) and the low insertion loss in the ''open'' state. The performance of a fully...... integrated submillimeter receiver circuit which comprises a flux-flow oscillator (FFO) as local oscillator, a superconducting variable attenuator, and a microwave SIS detector with tuned-out capacitance is also reported....

  15. The Role of DSD and Radio Wave Scattering in Rain Attenuation

    OpenAIRE

    Fiser, Ondrej

    2010-01-01

    The applicability, importance and properties of the rain drop size distribution was demonstrated in this chapter. It was also shown that DSD determines rain rate, radar reflectivity and rain attenuation of microwave signal. A part of this chapter describes scattering functions describing radiowave reflection from rain drop. One of the important results of this study is the following one: the radar reflectivity factor derived from the rain rate through the Z-R relation could be incorrect throu...

  16. X-Ray Attenuation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.; Toor, A.

    2000-03-03

    To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3rd-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intensity by many orders of magnitude without increasing the pulse-to-pulse variation. In this report we consider a possible solution for controlled attenuation of the LCLS x-ray radiation. We suggest using for this purpose a windowless gas-filled cell with the differential pumping. Although this scheme is easily realizable in principle, it has to be demonstrated that the attenuator can be made short enough to be practical and that the gas loads delivered to the vacuum line of sight (LOS) are acceptable. We are not going to present a final, optimized design. Instead, we will provide a preliminary analysis showing that the whole concept is robust and is worth further study. The spatial structure of the LCLS x-ray pulse at the location of the attenuator is shown in Fig. 1. The central high-intensity component, due to the FEL, has a FWHM of {approx}100 {micro}m. A second component, due to the undulator's broad band spontaneous radiation is seen as a much lower intensity ''halo'' with a FWHM of 1 mm. We discuss two versions of the attenuation cell. The first is directed towards a controlled attenuation of the FEL up to the 4 orders of magnitude in the intensity, with the spontaneous radiation halo being eliminated by collimators. In the second version, the spontaneous radiation is not sacrificed but the FEL component (as well as the first harmonic of the spontaneous radiation) gets attenuated by a more modest factor up to 100. We will make all the estimates assuming that the gas used in the attenuator is Xenon and that the energy of the FEL is 8.25 keV. At

  17. Radiative Transfer Model of Dust Attenuation Curves in Clumpy, Galactic Environments

    CERN Document Server

    Seon, Kwang-Il

    2016-01-01

    The attenuation of starlight by dust in galactic environments is investigated through models of radiative transfer in a spherical, clumpy ISM. Extinction properties for MW, LMC, and SMC dust types are considered. It is illustrated that the attenuation curves are primarily determined by the wavelength dependence of absorption rather than by the underlying extinction (absorption+scattering) curve. Attenuation curves consistent with the "Calzetti attenuation curve" are found by assuming the silicate-carbonaceous dust model for the MW, but with the 2175A absorption bump suppressed or absent. The discrepancy between our results and previous work that claimed the SMC-type dust to be the most likely origin of the Calzetti curve is ascribed to the difference in adopted albedos; this study uses the theoretically calculated albedos whereas the previous ones adopted empirically derived albedos from observations of reflection nebulae. It is also found that the model attenuation curves calculated with the MW dust are well...

  18. Design and performance analysis of total reflection-type secondary optics in concentrated photovoltaic module%应用于聚光光伏模组的全反射式二次聚光器的设计与性能分析

    Institute of Scientific and Technical Information of China (English)

    茹占强; 安志勇; 宋贺伦; 李望; 卢鑫; 于秋水; 张耀辉

    2011-01-01

    当前聚光光伏系统存在很多问题,比如跟踪器的跟踪精度偏低、聚焦光斑强度分布不均匀、聚焦光斑的形状跟太阳电池不匹配等,二次聚光器可以解决这些问题,从而提高高倍聚光光伏系统的光电转换效率.对高倍聚光光伏系统中的菲涅耳透镜和二次聚光器的聚光原理进行了简要分析,重点对全反射式二次聚光器进行了二维聚光的理论分析,并配合非成像光学的光线追迹方法,设计并加工了应用于某高倍聚光光伏系统的全反射式二次聚光器.对该二次聚光器的主要性能进行了仿真分析及评价,结果表明:该聚光器能提高高倍聚光光伏系统的整体性能.%At present, the high concentrated photovoltaic system has a lot of problems, for example,tracking accuracy of tracker is too low, focused spot irradiation distribution is ununiform, the shape of focused spot is different from the shape of solar cell, and so on.Secondary optics can improve the photoelectric conversion efficiency of the high concentrated photovoltaic system by solving these problems.The condensation principles of Fresnel lens and secondary optics were analyzed, in particularly twodimensional condensation theory about the total reflection-type secondary optics was analyzed.According to the results of theoretical analysis and the approach of ray trace of nonimaging optics, the total reflection-type secondary optics used in a high concentrated photovoltaic system was designed and processed.And some main performance of the secondary optics were analyzed and evaluated by simulation software.The conclusion is drawn that the total reflection-type secondary optics can improve the whole performance of the high concentrated photovoltaic system.

  19. Increased liking for a solution is not necessary for the attenuation of neophobia in rats

    OpenAIRE

    Neath, Karly N.; Limebeer, Cheryl L; Reilly, Steve; Parker, Linda A.

    2010-01-01

    Recent evidence suggests that liking and wanting of food rewards can be experimentally dissociated (e.g., Berridge, 1996); this dissociation extends to attenuated neophobia in the present study. Rats tend to eat less of a novel food than a familiar food, a phenomenon called neophobia. The present experiments evaluated whether attenuation of neophobia by prior exposure reflects enhanced liking of the flavor using the Taste Reactivity (TR) test. In Experiment 1, rats given five 10 sec TR trials...

  20. Suspended sediment profiles derived from spectral attenuation coefficients measurements using neural network method

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, G.; Suresh, T.; Matondkar, S.G.P.; Desa, E.; Kamath, S.S.

    total suspended matter values from water samples obtained at discrete depths at the same location. An artificial neural network (ANN) model has been used to derive suspended matter from the spectral values of beam attenuation coefficients measured using...

  1. Compact plasmonic variable optical attenuator

    DEFF Research Database (Denmark)

    Leosson, Kristjan; Rosenzveig, Tiberiu; Hermannsson, Pétur Gordon;

    2008-01-01

    We demonstrate plasmonic nanowire-based thermo-optic variable optical attenuators operating in the 1525-1625 nm wavelength range. The devices have a footprint as low as 1 mm, extinction ratio exceeding 40 dB, driving voltage below 3 V, and full modulation bandwidth of 1 kHz. The polarization...

  2. Characteristics of coda wave attenuation in Yunnan area

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The characteristic of seismic coda wave attenuation in Yunnan area in 7 frequency-bands range from 1 Hz to 20 Hz was estimated by using the local earthquake's waveform data recorded from 22 Yunnan digital seismic stations.Coda attenuation Q-c1 of each station was firstly calculated by single scattering method. Then, mean free path Le and seismic albedo Bo of each station were calculated, and scattering attenuation Q-1s and intrinsic attenuation Q-1i were separated from total attenuation Q-1t by multiple lapse time window analysis based on the multiple scattering model in uniform random isotropic scattering medium. The attenuating characteristics in Yunnan show that most value of Le are in 10~30 km, with maximal within 2~6 Hz;Bo are about 0.5 at 1~2 Hz, but less than 0.5at other frequency-bands, which means Q-1i is comparable with Q-1s at 1~2 Hz, and after 1~2 Hz, Q-1i is greater than Q-1s and dominates the attenuation process. Q-1c is close to Q-1i at other frequency bands except 1~2 Hz.Results show that Q-1 especially Qs-1 varies spatially, Q-1 in eastern Yunnan zone is a bit higher than in northwestern Yunnan zone;northwestern Yunnan zone higher than southwestern Yunnan zone. Comparing with other results in global, Qs-1 in Yunnan is lower than the global average value among these results, Q-1i is higher than the global average value, and Q-1t lies the middle among these results.

  3. Stormwater Attenuation by Green Roofs

    Science.gov (United States)

    Sims, A.; O'Carroll, D. M.; Robinson, C. E.; Smart, C. C.

    2014-12-01

    Innovative municipal stormwater management technologies are urgently required in urban centers. Inadequate stormwater management can lead to excessive flooding, channel erosion, decreased stream baseflows, and degraded water quality. A major source of urban stormwater is unused roof space. Green roofs can be used as a stormwater management tool to reduce roof generated stormwater and generally improve the quality of runoff. With recent legislation in some North American cities, including Toronto, requiring the installation of green roofs on large buildings, research on the effectiveness of green roofs for stormwater management is important. This study aims to assess the hydrologic response of an extensive sedum green roof in London, Ontario, with emphasis on the response to large precipitation events that stress municipal stormwater infrastructure. A green roof rapidly reaches field capacity during large storm events and can show significantly different behavior before and after field capacity. At field capacity a green roof has no capillary storage left for retention of stormwater, but may still be an effective tool to attenuate peak runoff rates by transport through the green roof substrate. The attenuation of green roofs after field capacity is linked to gravity storage, where gravity storage is the water that is temporarily stored and can drain freely over time after field capacity has been established. Stormwater attenuation of a modular experimental green roof is determined from water balance calculations at 1-minute intervals. Data is used to evaluate green roof attenuation and the impact of field capacity on peak flow rates and gravity storage. In addition, a numerical model is used to simulate event based stormwater attenuation. This model is based off of the Richards equation and supporting theory of multiphase flow through porous media.

  4. Analysis of multiscale scattering and poroelastic attenuation in a real sedimentary rock sequence

    Science.gov (United States)

    Hackert; Parra

    2000-06-01

    Compressional waves in heterogeneous permeable media experience attenuation from both scattering and induced pore scale flow of the viscous saturating fluid. For a real, finely sampled sedimentary sequence consisting of 255 layers and covering 30 meters of depth, elastic and poroelastic computer models are applied to investigate the relative importance of scattering and fluid-flow attenuation. The computer models incorporate the known porosity, permeability, and elastic properties of the sand/shale sequence in a binary medium, plane layered structure. The modeled elastic scattering attenuation is well described by stochastic medium theory if two-length scale statistics are applied to reflect the relative thickness of the shale layers when compared to the sand layers. Under the poroelastic Biot/squirt flow model, fluid-flow attenuation from the moderate permeability (10(-14) m2) sands may be separated in the frequency domain from the attenuation due to the low permeability (5 x 10(-17) m2) shale layers. Based on these models, the overall attenuation is well approximated by the sum of the scattering attenuation from stochastic medium theory and the volume weighted average of the attenuations of the sequence member rocks. These results suggest that a high permeability network of sediments or fractures in a lower permeability host rock may have a distinct separable attenuation signature, even if the overall volume of high permeability material is low. Depending on the viscosity of the saturating fluid, the magnitude of the flow-based attenuation can dominate or be dominated by the scattering attenuation at typical sonic logging frequencies (approximately 10 kHz).

  5. REFLECTION AND TRANSLATION

    Directory of Open Access Journals (Sweden)

    Korolkova Svetlana Azadovna

    2014-06-01

    Full Text Available The article deals with the correlation between reflection and translation and proves the possibility to extrapolate the notion of "hermeneutic circle" into translation. Translation, which is understood as a specific speech activity, has a hermeneutic character as in its basis there is a "reflexive delay", a specific state of intelligence which occurs as a result of a language, ethnic or cultural barrier and demands a reflective action. At that, the circle is transformed into a spiral, which lets conceive the essence of every text fragment through its integration into the former comprehended layer. Interpretation, a reflexive action, which has a three-level structure, creates a unified image of a foreign text in the translator's consciousness and provides the integration of the text concept into the translator's pragmatic net, the representative of a foreign language community, and promotes the target text creation which conforms to the recipient's expectations. At that, the interpreter's personality, their ability to interpret, total existential competence and active position are of precedence for sense comprehension. Reflexive abilities refer to the category of the over-subjective; however, they provide adequate interpretation of the source text and creation of the so-called natural target text. The so-called des-objective reading, predicted synthesis and retrospective analysis are the key notions for the translator. Such abilities are the basis of the professional competence of the translator, who becomes not only a professional but also an intelligent personality that has existential and academic background.

  6. ENHANCEMENTS TO NATURAL ATTENUATION: SELECTED CASE STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K; W. H. Albright, W; E. S. Becvar, E; C. H. Benson, C; T. O. Early, T; E. Hood, E; P. M. Jardine, P; M. Lorah, M; E. Majche, E; D. Major, D; W. J. Waugh, W; G. Wein, G; O. R. West, O

    2007-05-15

    In 2003 the US Department of Energy (DOE) embarked on a project to explore an innovative approach to remediation of subsurface contaminant plumes that focused on introducing mechanisms for augmenting natural attenuation to achieve site closure. Termed enhanced attenuation (EA), this approach has drawn its inspiration from the concept of monitored natural attenuation (MNA).

  7. Reflectable bases for affine reflection systems

    CERN Document Server

    Azam, Saeid; Yousofzadeh, Malihe

    2011-01-01

    The notion of a "root base" together with its geometry plays a crucial role in the theory of finite and affine Lie theory. However, it is known that such a notion does not exist for the recent generalizations of finite and affine root systems such as extended affine root systems and affine reflection systems. As an alternative, we introduce the notion of a "reflectable base", a minimal subset $\\Pi$ of roots such that the non-isotropic part of the root system can be recovered by reflecting roots of $\\Pi$ relative to the hyperplanes determined by $\\Pi$. We give a full characterization of reflectable bases for tame irreducible affine reflection systems of reduced types, excluding types $E_{6,7,8}$. As a byproduct of our results, we show that if the root system under consideration is locally finite then any reflectable base is an integral base.

  8. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Gary Mavko; Jack Dvorkin

    2002-01-01

    In Section 1 of this first report we will describe the work we are doing to collect and analyze rock physics data for the purpose of modeling seismic attenuation from other measurable quantities such as porosity, water saturation, clay content and net stress. This work and other empirical methods to be presented later, will form the basis for ''Q pseudo-well modeling'' that is a key part of this project. In Section 2 of this report, we will show the fundamentals of a new method to extract Q, dispersion, and attenuation from field seismic data. The method is called Gabor-Morlet time-frequency decomposition. This technique has a number of advantages including greater stability and better time resolution than spectral ratio methods.

  9. Chlorine signal attenuation in concrete.

    Science.gov (United States)

    Naqvi, A A; Maslehuddin, M; ur-Rehman, Khateeb; Al-Amoudi, O S B

    2015-11-01

    The intensity of prompt gamma-ray was measured at various depths from chlorine-contaminated silica fume (SF) concrete slab concrete specimens using portable neutron generator-based prompt gamma-ray setup. The intensity of 6.11MeV chloride gamma-rays was measured from the chloride contaminated slab at distance of 15.25, 20.25, 25.25, 30.25 and 35.25cm from neutron target in a SF cement concrete slab specimens. Due to attenuation of thermal neutron flux and emitted gamma-ray intensity in SF cement concrete at various depths, the measured intensity of chlorine gamma-rays decreases non-linearly with increasing depth in concrete. A good agreement was noted between the experimental results and the results of Monte Carlo simulation. This study has provided useful experimental data for evaluating the chloride contamination in the SF concrete utilizing gamma-ray attenuation method.

  10. Reflectivity, reflexivity and situated reflective practice

    OpenAIRE

    Malthouse, R; Roffey-Barentsen, J; Watts, DM

    2014-01-01

    This paper describes an aspect of reflective practice referred to as ‘Situated Reflective Practice’ (SRP). The overarching theory is derived from social theories of structuration and reflexivity. In particular, from Giddens’s (1984) theory of structuration, this sees social life as interplay of agency and structure. Discussion of the research reported here centres on the nature of such situated reflection, considers related literature and presents the data collected in a recent small-scale st...

  11. Modes of collaborative reflection

    OpenAIRE

    Degeling, Martin; Prilla, Michael

    2011-01-01

    In this paper, we describe different modes of collaborative reflection as processes of learning at the workplace. We explain why reflection is a decisive means of learning and - based on the modes we describe - how groups of people can be supported in reflection together. For this, we describe how scheduled, concurrent and spontaneous collaborative reflection can be supported by articulation, guidance and synergizing.

  12. Reflectivity, Reflexivity and Situated Reflective Practice

    Science.gov (United States)

    Malthouse, Richard; Roffey-Barentsen, Jodi; Watts, Mike

    2014-01-01

    This paper describes an aspect of reflective practice referred to as situated reflective practice. The overarching theory is derived from social theories of structuration and reflexivity. In particular, from Giddens' theory of structuration, which sees social life as an interplay of agency and structure. Discussion of the research reported…

  13. Attenuation in silica-based optical fibers

    DEFF Research Database (Denmark)

    Wandel, Marie Emilie

    2006-01-01

    absorption peaks in order to investigate the cause of an unusual high attenuation in a series of transmission fibers. Strong indications point to Ni2+ in octahedral coordination as being the cause of the high attenuation. The attenuation of fibers having a high core refractive index is analyzed and the cause...... well as the viscosity profile a lower attenuation of high index fibers can be obtained. The design of dispersion compensating fibers using the super mode approach is described, the object being to design dispersion compensating fibers for dispersion compensating fiber modules having a low attenuation......, described by a high figure of merit. The major trade offs encountered when designing dispersion compensating fibers with high figure of merit are to obtain a very negative dispersion, low attenuation and low micro bend loss at the same time. The model for predicting the attenuation of high index fibers is...

  14. Chemical morphology of Areca nut characterized directly by Fourier transform near-infrared and mid-infrared microspectroscopic imaging in reflection modes.

    Science.gov (United States)

    Chen, Jian-Bo; Sun, Su-Qin; Zhou, Qun

    2016-12-01

    Fourier transform near-infrared (NIR) and mid-infrared (MIR) imaging techniques are essential tools to characterize the chemical morphology of plant. The transmission imaging mode is mostly used to obtain easy-to-interpret spectra with high signal-to-noise ratio. However, the native chemical compositions and physical structures of plant samples may be altered when they are microtomed for the transmission tests. For the direct characterization of thick plant samples, the combination of the reflection NIR imaging and the attenuated total reflection (ATR) MIR imaging is proposed in this research. First, the reflection NIR imaging method can explore the whole sample quickly to find out typical regions in small sizes. Next, each small typical region can be measured by the ATR-MIR imaging method to reveal the molecular structures and spatial distributions of compounds of interest. As an example, the chemical morphology of Areca nut section is characterized directly by the above approach. PMID:27374557

  15. UV to far-IR reflectance spectra of carbonaceous chondrites. I. Implications for remote characterization of dark primitive asteroids targeted by sample-return missions

    CERN Document Server

    Trigo-Rodriguez, Josep M; Llorca, Jordi; Fornasier, Sonia; Barucci, Maria A; Belskaya, Irina; Martins, Zita; Rivkin, Andy S; Dotto, Elisabetta; Madiedo, José M; Alonso-Azcárate, Jacinto

    2013-01-01

    We analyze here a wide sample of carbonaceous chondrites from historic falls (e.g. Allende, Cold Bokkeveld, Kainsaz, Leoville, Murchison, Murray and Orgueil), and from NASA Antarctic collection in order to get clues on the role of aqueous alteration in promoting the reflectance spectra diversity evidenced in the most primitive chondrite groups. We particularly focus in the identification of spectral features and behavior that can be used to remotely identify primitive carbonaceous asteroids. The selected meteorite specimens are a sample large enough to exemplify how laboratory reflectance spectra of rare groups of carbonaceous chondrites exhibit distinctive features that can be used to remotely characterize the spectra of primitive asteroids. Our spectra cover the full electromagnetic spectrum from 0.2 to 25 microns by using two spectrometers. First one is a UV-NIR spectrometer that covers the 0.2 to 2 microns window, while the second one is an Attenuated Total Reflectance IR spectrometer covering the 2 to 25...

  16. Coherent specular reflection of resonant light from a dense ensemble of motionless point-like scatters in a slab geometry

    Science.gov (United States)

    Kuraptsev, A. S.; Sokolov, I. M.; Fofanov, Ya. A.

    2016-03-01

    We analyze resonant light scattering from a dense and disordered ensemble of motionless point-like scatters with uniform (on average) spatial distribution of the density. The average interatomic distance is considered comparable with the resonant wavelength and the mean free path of photon. The inhomogeneity of dipole-dipole interaction near the surface is discussed. Angular distribution of the light scattered from a medium in a slab geometry is calculated. The total reflected light power P and the reflectivity R depending on the optical thickness of a medium bz are analyzed. It is shown that in the case of small optical thickness (bz ≪ 1) P(bz) ∝ bz2 and R(bz) ∝ bz. With further increasing of the optical thickness we observe oscillations of the dependencies P(bz) and R(bz). The attenuation coefficient of these oscillations is discussed.

  17. Review of methods to attenuate shock/blast waves

    Science.gov (United States)

    Igra, O.; Falcovitz, J.; Houas, L.; Jourdan, G.

    2013-04-01

    Quick and reliable shock wave attenuation is the goal of every protection facility and therefore it is not surprising that achieving this has drawn much attention during the past hundred years. Different options have been suggested; their usefulness varying from a reasonable protection to the opposite, a shock enhancement. An example for a suggestion for shock mitigation that turned out to be an enhancement of the impinging shock wave was the idea to cover a protected object with a foam layer. While the pressure behind the reflected shock wave from the foam frontal surface was smaller than that recorded in a similar reflection from a rigid wall [25], the pressure on the “protected” surface, attached to the foam's rear-surface, was significantly higher than that recorded in a similar reflection from a bare, rigid wall [11]. In protecting humans and installations from destructive shock and/or blast waves the prime goal is to reduce the wave amplitude and the rate of pressure increase across the wave front. Both measures result in reducing the wave harmful effects. During the past six decades several approaches for achieving the desired protection have been offered in the open literature. We point out in this review that while some of the suggestions offered are practical, others are impractical. In our discussion we focus on recent schemes for shock/blast wave attenuation, characterized by the availability of reliable measurements (notably pressure and optical diagnostics) as well as high-resolution numerical simulations.

  18. Association of somatic burden of disease with age and neuropsychological measures in attenuated mucopolysaccharidosis types I, II and VI

    Directory of Open Access Journals (Sweden)

    Alia Ahmed

    2016-06-01

    Conclusions: Physical Symptom Score increased with age in attenuated MPS I, II and VI, reflecting progressive somatic burden of disease despite treatment with enzyme replacement therapy. Furthermore, the association of increased somatic disease burden with decreased neurocognitive ability suggests that both measures reflect disease severity and are not independent.

  19. Understanding reflective practice.

    Science.gov (United States)

    Nicol, Jacqueline Sian; Dosser, Isabel

    2016-05-01

    The Nursing and Midwifery Council (NMC) requires that nurses and midwives use feedback as an opportunity for reflection and learning, to improve practice. The NMC revalidation process stipulates that practitioners provide examples of how they have achieved this. To reflect in a meaningful way, it is important to understand what is meant by reflection, the skills required, and how reflection can be undertaken successfully. Traditionally, reflection occurs after an event encountered in practice. The authors challenge this perception, suggesting that reflection should be undertaken before, during and after an event. This article provides practical guidance to help practitioners use reflective models to write reflective accounts. It also outlines how the reflective process can be used as a valuable learning tool in preparation for revalidation. PMID:27154119

  20. Settlement prediction model of slurry suspension based on sedimentation rate attenuation

    Directory of Open Access Journals (Sweden)

    Shuai-jie GUO

    2012-03-01

    Full Text Available This paper introduces a slurry suspension settlement prediction model for cohesive sediment in a still water environment. With no sediment input and a still water environment condition, control forces between settling particles are significantly different in the process of sedimentation rate attenuation, and the settlement process includes the free sedimentation stage, the log-linear attenuation stage, and the stable consolidation stage according to sedimentation rate attenuation. Settlement equations for sedimentation height and time were established based on sedimentation rate attenuation properties of different sedimentation stages. Finally, a slurry suspension settlement prediction model based on slurry parameters was set up with a foundation being that the model parameters were determined by the basic parameters of slurry. The results of the settlement prediction model show good agreement with those of the settlement column experiment and reflect the main characteristics of cohesive sediment. The model can be applied to the prediction of cohesive soil settlement in still water environments.

  1. Assimilation of attenuated data from X-band network radars using ensemble Kalman filter

    Science.gov (United States)

    Cheng, Jing

    To use reflectivity data from X-band radars for quantitative precipitation estimation and storm-scale data assimilation, the effect of attenuation must be properly accounted for. Traditional approaches try to make correction to the attenuated reflectivity first before using the data. An alternative, theoretically more attractive approach builds the attenuation effect into the reflectivity observation operator of a data assimilation system, such as an ensemble Kalman filter (EnKF), allowing direct assimilation of the attenuated reflectivity and taking advantage of microphysical state estimation using EnKF methods for a potentially more accurate solution. This study first tests the approach for the CASA (Center for Collaborative Adaptive Sensing of the Atmosphere) X-band radar network configuration through observing system simulation experiments (OSSE) for a quasi-linear convective system (QLCS) that has more significant attenuation than isolated storms. To avoid the problem of potentially giving too much weight to fully attenuated reflectivity, an analytical, echo-intensity-dependent model for the observation error (AEM) is developed and is found to improve the performance of the filter. By building the attenuation into the forward observation operator and combining it with the application of AEM, the assimilation of attenuated CASA observations is able to produce a reasonably accurate analysis of the QLCS inside CASA radar network coverage. Compared with foregoing assimilation of radar data with weak radar reflectivity or assimilating only radial velocity data, our method can suppress the growth of spurious echoes while obtaining a more accurate analysis in the terms of root-mean-square (RMS) error. Sensitivity experiments are designed to examine the effectiveness of AEM by introducing multiple sources of observation errors into the simulated observations. The performance of such an approach in the presence of resolution-induced model error is also evaluated and

  2. Imaging Rayleigh wave attenuation with USArray

    Science.gov (United States)

    Bao, Xueyang; Dalton, Colleen A.; Jin, Ge; Gaherty, James B.; Shen, Yang

    2016-07-01

    The EarthScope USArray provides an opportunity to obtain detailed images of the continental upper mantle at an unprecedented scale. The majority of mantle models derived from USArray data to date contain spatial variations in seismic-wave speed; however, in many cases these data sets do not by themselves allow a non-unique interpretation. Joint interpretation of seismic attenuation and velocity models can improve upon the interpretations based only on velocity and provide important constraints on the temperature, composition, melt content, and volatile content of the mantle. The surface wave amplitudes that constrain upper-mantle attenuation are sensitive to factors in addition to attenuation, including the earthquake source excitation, focusing and defocusing by elastic structure, and local site amplification. Because of the difficulty of isolating attenuation from these other factors, little is known about the attenuation structure of the North American upper mantle. In this study, Rayleigh wave traveltime and amplitude in the period range 25-100 s are measured using an interstation cross-correlation technique, which takes advantage of waveform similarity at nearby stations. Several estimates of Rayleigh wave attenuation and site amplification are generated at each period, using different approaches to separate the effects of attenuation and local site amplification on amplitude. It is assumed that focusing and defocusing effects can be described by the Laplacian of the traveltime field. All approaches identify the same large-scale patterns in attenuation, including areas where the attenuation values are likely contaminated by unmodelled focusing and defocusing effects. Regionally averaged attenuation maps are constructed after removal of the contaminated attenuation values, and the variations in intrinsic shear attenuation that are suggested by these Rayleigh wave attenuation maps are explored.

  3. Envelope broadening and scattering attenuation of a scalar wavelet in random media having power-law spectra

    Science.gov (United States)

    Sato, Haruo

    2016-01-01

    Peak delay and envelope broadening of an S-wavelet with travel distance increasing are seen in short-period seismograms of small earthquakes. Those phenomena are results of scattering by random velocity inhomogeneities in the earth medium. As shown in sonic well-log data we may suppose that random velocity fluctuation has power-law spectra even in the seismic spectral range. As a simple mathematical model, we study how the envelope of a scalar wavelet varies in von Kármán-type random media, which have power-law spectra at large wavenumbers. Since the centre wavenumber of a wavelet is a unique scale in the power-law spectral range, using it as a reference, we divide the random media into the low-wavenumber spectral (long-scale) component and the high-wavenumber spectral (short-scale) component. For the wave propagation through the long-scale component of random media, we may apply the parabolic approximation to the wave equation. Using the Markov approximation, which is a stochastic extension of the phase screen method, we directly synthesize the energy density, which is the mean-square (MS) envelope of a wavelet in a given frequency band. The envelope duration increases according to the second power of travel distance. There is an additional factor, the wandering effect which increases the envelope duration according to the traveltime fluctuation. Wide angle scattering caused by the short-scale component of random media attenuates wave amplitude with travel distance increasing. We use the total scattering coefficient of the short-scale component as a measure of scattering attenuation per distance, which is well described by the Born approximation. Multiplying the exponential scattering attenuation factor by the MS envelope derived by the Markov approximation, we can synthesize the MS envelope reflecting all the spectral components of random media. When the random medium power spectra have a steep role-off at large wavenumbers, the envelope broadening is small and

  4. Restricted total stability and total attractivity

    Directory of Open Access Journals (Sweden)

    Giuseppe Zappala'

    2006-08-01

    Full Text Available In this paper the new concepts of restricted total stability and total attractivity is formulated. For this purpose the classical theory of Malkin with suitable changes and the theory of limiting equations, introduced by Sell developed by Artstein and Andreev, are used. Significant examples are presented.

  5. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  6. Magnetoelectric Composite Based Microwave Attenuator

    Science.gov (United States)

    Tatarenko, A. S.; Srinivasan, G.

    2005-03-01

    Ferrite-ferroelectric composites are magnetoelectric (ME) due to their response to elastic and electromagnetic force fields. The ME composites are characterized by tensor permittivity, permeability and ME susceptibility. The unique combination of magnetic, electrical, and ME interactions, therefore, opens up the possibility of electric field tunable ferromagnetic resonance (FMR) based devices [1]. Here we discuss an ME attenuator operating at 9.3 GHz based on FMR in a layered sample consisting of lead magnesium niobate-lead titanate bonded to yttrium iron garnet (YIG) film on a gadolinium gallium garnet substrate. Electrical tuning is realized with the application of a control voltage due to ME effect; the shift is 0-15 Oe as E is increased from 0 to 3 kV/cm. If the attenuator is operated at FMR, the corresponding insertion loss will range from 25 dB to 2 dB. 1. S. Shastry and G. Srinivasan, M.I. Bichurin, V.M. Petrov, A.S. Tatarenko. Phys. Rev. B, 70 064416 (2004). - supported by grants the grants from the National Science Foundation (DMR-0302254), from Russian Ministry of Education (Å02-3.4-278) and from Universities of Russia Foundation (UNR 01.01.026).

  7. Square and Delta reflection

    OpenAIRE

    Fontanella, Laura; Hayut, Yair

    2016-01-01

    Starting from infinitely many supercompact cardinals, we force a model of ZFC where $\\aleph_{\\omega^2+1}$ satisfies simultaneously a strong principle of reflection, called $\\Delta$-reflection, and a version of the square principle, denoted $\\square(\\aleph_{\\omega^2+1}).$ Thus we show that $\\aleph_{\\omega^2+1}$ can satisfy simultaneously a strong reflection principle and an anti-reflection principle.

  8. Teaching Critical Reflection

    Science.gov (United States)

    Smith, Elizabeth

    2011-01-01

    Despite long-standing commitment to the notion of critical reflection across the healthcare professions it is unusual for critical theory and practice to be taught as explicit subjects in healthcare higher education. There is evidence to show that reflective techniques such as critical portfolios and reflective diaries can help students to…

  9. Liberating Moral Reflection

    Science.gov (United States)

    Horell, Harold D.

    2013-01-01

    The author argues that if we are to foster life-giving and liberating moral reflection, we must first liberate moral reflection from distortions; specifically, from the distorting effects of moral insensitivity, destructive moral relativism, and confusions resulting from a failure to understand the dynamics of moral reflection. The author proposes…

  10. Reflective Learning in Practice.

    Science.gov (United States)

    Brockbank, Anne, Ed.; McGill, Ian, Ed.; Beech, Nic, Ed.

    This book contains 22 papers on reflective learning in practice. The following papers are included: "Our Purpose" (Ann Brockbank, Ian McGill, Nic Beech); "The Nature and Context of Learning" (Ann Brockbank, Ian McGill, Nic Beech); "Reflective Learning and Organizations" (Ann Brockbank, Ian McGill, Nic Beech); "Reflective Learning in Practice" (Ann…

  11. Photodetachment of H- near a Partially Reflecting Surface-Ⅰ

    Institute of Scientific and Technical Information of China (English)

    A.Afaq

    2008-01-01

    Theoretical and interpretative study on the subject of photodetachment of H- near a partially reflecting surface is presented,and the absorption effect of the surface is investigated on the total and differential cross sections using a theoretical imaging method.To understand the absorption effect,a reflection parameter K is introduced as a multiplicative factor to the outgoing detached-electron wave of H- propagating towards the wall.The reflection parameter measures.how much electron wave would reflect from the surface;K=0 corresponds to no reflection and K=1 corresponds to the total reflection.

  12. An adaptive noise attenuation method for edge and amplitude preservation

    Institute of Scientific and Technical Information of China (English)

    Cai Han-Peng; He Zhen-Hua; Li Ya-Lin; He Guang-Ming; Zou Wen; Zhang Dong-Jun; Liu Pu

    2014-01-01

    Noise intensity distributed in seismic data varies with different frequencies or frequency bands; thus, noise attenuation on the full-frequency band affects the dynamic properties of the seismic reflection signal and the subsequent seismic data interpretation, reservoir description, hydrocarbon detection, etc. Hence, we propose an adaptive noise attenuation method for edge and amplitude preservation, wherein the wavelet packet transform is used to decompose the full-band seismic signal into multiband data and then process these data using nonlinear anisotropic dip-oriented edge-preservingfi ltering. In the fi ltering, the calculated diffusion tensor from the structure tensor can be exploited to establish the direction of smoothing. In addition, the fault confidence measure and discontinuity operator can be used to preserve the structural and stratigraphic discontinuities and edges, and the decorrelation criteria can be used to establish the number of iterations. These parameters can minimize the intervention and subjectivity of the interpreter, and simplify the application of the proposed method. We applied the proposed method to synthetic and real 3D marine seismic data. We found that the proposed method could be used to attenuate noise in seismic data while preserving the effective discontinuity information and amplitude characteristics in seismic refl ection waves, providing high-quality data for interpretation and analysis such as high-resolution processing, attribute analysis, and inversion.

  13. Ultrasound fields in an attenuating medium

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Gandhi,, D; O'Brien,, W.D., Jr.

    1993-01-01

    Ultrasound fields propagating in tissue will undergo changes in shape not only due to diffraction, but also due to the frequency dependent attenuation. Linear fields can be fairly well predicted for a non-attenuating medium like water by using the Tupholme-Stepanishen method for calculating...... it into a frequency dependent part and frequency independent part. The latter results in an attenuation factor that is multiplied onto the responses from the individual elements, and the frequency dependent part is handled by attenuating the basic one-dimensional pulse. The influence on ultrasound fields from...

  14. Reflection Positive Doubles

    CERN Document Server

    Jaffe, Arthur

    2016-01-01

    Here we introduce reflection positive doubles, a general framework for reflection positivity, covering a wide variety of systems in statistical physics and quantum field theory. These systems may be bosonic, fermionic, or parafermionic in nature. Within the framework of reflection positive doubles, we give necessary and sufficient conditions for reflection positivity. We use a reflection-invariant cone to implement our construction. Our characterization allows for a direct interpretation in terms of coupling constants, making it easy to check in concrete situations. We illustrate our methods with numerous examples.

  15. Wave Reflection Coefficient Spectrum

    Institute of Scientific and Technical Information of China (English)

    俞聿修; 邵利民; 柳淑学

    2003-01-01

    The wave reflection coefficient frequency spectrum and directional spectrum for concrete face slope breakwaters and rubble mound breakwaters are investigated through physical model tests in the present study. The reflection coefficients of oblique irregular waves are analyzed by the Modified Two-Point Method (MTPM) proposed by the authors. The results show that the wave reflection coefficient decreases with increasing wave frequency and incident angle or decreasing structure slope. The reflection coefficient frequency spectrum and its variation with Iribarren number are given in this paper. The paper also suggests an empirical 3-dimensional reflection coefficient spectrum, i.e. reflection coefficient directional spectrum, which can be used to illustrate quantitatively the variation of reflection coefficient with the incident angle and the Iribarren number for oblique irregular waves.

  16. Ultrasonic attenuation in cuprate superconductors

    Indian Academy of Sciences (India)

    T Gupta; D M Gaitonde

    2002-05-01

    We calculate the longitudinal ultrasonic attenuation rate (UAR) in clean d-wave superconductors in the Meissner and the mixed phases. In the Meissner phase we calculate the contribution of previously ignored processes involving the excitation of a pair of quasi-holes or quasi-particles. There is a contribution ∝ in the regime B ≪ F ≪ 0 and a contribution ∝ 1/ in the regime F ≪ B ≪ 0. We find that these contributions to the UAR are large and cannot be ignored. In the mixed phase, using a semi-classical description, we calculate the electronic quasi-particle contribution to the UAR which at very low , has a independent term proportional to $\\sqrt{H}$.

  17. Attenuation characteristics of gypsum wallboard

    International Nuclear Information System (INIS)

    Increased cost of lead is promoting enhanced usage of common building materials for shielding in diagnostic medical and dental facilities where only a few half-value layers (HVLs) are needed. Attenuation of primary beam X-ray photons in gypsum wallboard as a function of kVp, filtration, and wallboard thickness have been measured. Findings, obtained using a Victoreen 555 with an 0.1 DAS probe in poor geometry, are substantially in agreement with the sparse data in the literature but extend to thicker wall configurations and different kVp and filtration parameters. These findings are of value in maximizing the benefit/cost ratio for diagnostic shielding, and strengthen the conviction that, where used for shielding purposes, common building materials must be installed carefully and HVL-depth dependence considered thoroughly. (author)

  18. Total light absorption in graphene

    CERN Document Server

    Thongrattanasiri, Sukosin; de Abajo, F Javier Garcia

    2011-01-01

    We demonstrate that 100% light absorption can take place in a single patterned sheet of doped graphene. General analysis shows that a planar array of small lossy particles exhibits full absorption under critical-coupling conditions provided the cross section of each individual particle is comparable to the area of the lattice unit-cell. Specifically, arrays of doped graphene nanodisks display full absorption when supported on a substrate under total internal reflection, and also when lying on a dielectric layer coating a metal. Our results are relevant for infrared light detectors and sources, which can be made tunable via electrostatic doping of graphene.

  19. Measurment and Interpretation of Seismic Attenuation for Hydrocarbon Exploration

    Energy Technology Data Exchange (ETDEWEB)

    Michael Batzle; Luca Duranti; James Rector; Steve Pride

    2007-12-31

    This research project is the combined effort of several leading research groups. Advanced theoretical work is being conducted at the Lawrence Berkeley National Laboratory. Here, the fundamental controls on loss mechanisms are being examined, primarily by use of numerical models of heterogeneous porous media. At the University of California, Berkeley, forward modeling is combined with direct measurement of attenuation. This forward modeling provides an estimate of the influence of 1/Q on the observed seismic signature. Direct measures of losses in Vertical Seismic Profiles (VSPs) indicate mechanisms to separate scattering versus intrinsic losses. At the Colorado School of Mines, low frequency attenuation measurements are combined with geologic models of deep water sands. ChevronTexaco is our corporate cosponsor and research partner. This corporation is providing field data over the Genesis Field, Gulf of Mexico. In addition, ChevronTexaco has rebuilt and improved their low frequency measurement system. Soft samples representative of the Genesis Field can now be measured for velocities and attenuations under reservoir conditions. Throughout this project we have: Assessed the contribution of mechanical compaction on time-lapse monitoring; Developed and tested finite difference code to model dispersion and attenuation; Heterogeneous porous materials were modeled and 1/Q calculated vs. frequency; 'Self-affine' heterogeneous materials with differing Hurst exponent modeled; Laboratory confirmation was made of meso-scale fluid motion influence on 1/Q; Confirmed theory and magnitude of layer-based scattering attenuation at Genesis and at a shallow site in California; Scattering Q's of between 40 and 80 were obtained; Measured very low intrinsic Q's (2-20) in a partially saturated vadose zone VSP; First field study to separate scattering and intrinsic attenuation in real data set; Revitalized low frequency device at ChevronTexaco's Richmond lab

  20. Lung attenuation measurements in healthy young adults.

    NARCIS (Netherlands)

    Smit, H.J.M.; Golding, R.P.; Schramel, F.M.N.H.; Devillé, W.L.; Manoliu, R.A.; Postmus, P.E.

    2003-01-01

    Background: High-resolution computed tomography (HRCT) attenuation measurements may be more sensitive in finding early emphysematous changes in relatively young subjects than lung function measurements. Objectives: To define lung attenuation parameters in smokers and never-smokers. Methods: A prospe

  1. Simple parameterization of nuclear attenuation data

    CERN Document Server

    Akopov, N; Akopov, Z

    2007-01-01

    Based on the nuclear attenuation data obtained by the HERMES experiment on nitrogen and krypton nuclei, it is shown that the nuclear attenuation $R_M^{h}$ can be parametrised in a form of a linear polynomial $P_1=a_{11}$ + $\\tau a_{12}$, where $\\tau$ is the formation time, which depends on the energy of the virtual photon $\

  2. Media for Reflection

    DEFF Research Database (Denmark)

    Knudsen, Morten

    2016-01-01

    This article develops the concept media for reflection in the interest of conceptualizing the interpretative frames that enable and limit reflection in management and leadership education. The concept ‘media for reflection’ allows us to conceptualize the social and cultural mediation of reflection...... without reducing reflection to an effect of the social structures and cultural norms in which it is embedded. Based on the developed theoretical framework, this article analyses how a renaissance ‘mirror for princes’ and contemporary research-based management education mediate reflection. The content...... of the mediations is analysed as well as the societal and organizational background. Furthermore, the means by which the two media enable and limit reflection in different ways is compared. Finally, the article discusses possible implications of the analysis in terms of management and leadership education....

  3. Qualidade total do produto Products total quality

    Directory of Open Access Journals (Sweden)

    Henrique Silveira de Almeida

    1992-06-01

    Full Text Available O texto aborda o conceito de qualidade total do produto, seus determinantes, bem como as dimensões que compõem essa qualidade. Parte-se do pressuposto de que a qualidade do produto deve ser avaliada pela satisfação total do consumidor. Para o consumidor a qualidade do produto envolve pelo menos as seguintes dimensões: a qualidade do produto em si; a qualidade do produto ao longo do tempo; a qualidade dos serviços associados ao uso do produto; e o custo do ciclo de vida do produto. O trabalho procura detalhar e discutir cada uma dessas dimensões da qualidade, tendo em vista a satisfação do consumidor.The paper concerns to the concept of product's total quality, its determinants, and the dimensions wich constitute this quality. We admit that product quality should be evaluated via consumer's total satisfaction. Product quality for consumers includes at least the following dimensions: the product quality per se; the performance of product quality over time; the quality of services related to the use of the product; and the product lifecycle costs. This study seeks to specify and to discuss each of these quality dimensions related to consumer's satisfaction.

  4. Reflection in professional practice

    OpenAIRE

    Hetzner, Stefanie Bianca

    2014-01-01

    The purpose of this thesis is to contribute to the research on professional learning through reflective practice. The main goal is to examine—against the backdrop of workplace changes and errors—individual and contextual factors that are theoretically assumed to influence reflection in the context of professional work. Reflective practice is defined as a retrospective but future- and goal-oriented cognitive-affective process that basically involves (a) the awareness and review of incident...

  5. Correlation of S-Band Weather Radar Reflectivity and ACTS Propagation Data in Florida

    Science.gov (United States)

    Wolfe, Eric E.; Flikkema, Paul G.; Henning, Rudolf E.

    1997-01-01

    Previous work has shown that Ka-band attenuation due to rainfall and corresponding S-band reflectivity are highly correlated. This paper reports on work whose goal is to determine the feasibility of estimation and, by extension, prediction of one parameter from the other using the Florida ACTS propagation terminal (APT) and the nearby WSR-88D S-band Doppler weather radar facility operated by the National Weather Service. This work is distinguished from previous efforts in this area by (1) the use of a single-polarized radar, preventing estimation of the drop size distribution (e.g., with dual polarization) and (2) the fact that the radar and APT sites are not co-located. Our approach consists of locating the radar volume elements along the satellite slant path and then, from measured reflectivity, estimating the specific attenuation for each associated path segment. The sum of these contributions yields an estimation of the millimeter-wave attenuation on the space-ground link. Seven days of data from both systems are analyzed using this procedure. The results indicate that definite correlation of S-band reflectivity and Ka-band attenuation exists even under the restriciton of this experiment. Based on these results, it appears possible to estimate Ka-band attenuation using widely available operational weather radar data. Conversely, it may be possible to augment current radar reflectivity data and coverage with low-cost attenuation or sky temperature data to improve the estimation of rain rates.

  6. Neutron attenuation characteristics of polyethylene, polyvinyl chloride, and heavy aggregate concrete and mortars.

    Science.gov (United States)

    Abdul-Majid, S; Othman, F

    1994-03-01

    Polyethylene and polyvinyl chloride pellets were introduced into concrete to improve its neutron attenuation characteristics while several types of heavy coarse aggregates were used to improve its gamma ray attenuation properties. Neutron and gamma ray attenuation were studied in concrete samples containing coarse aggregates of barite, pyrite, basalt, hematite, and marble as well as polyethylene and polyvinyl chloride pellets in narrow-beam geometry. The highest neutron attenuation was shown by polyethylene mortar, followed by polyvinyl chloride mortar; barite and pyrite concrete showed higher gamma ray attenuation than ordinary concrete. Broad-beam and continuous (infinite) medium geometries were used to study the neutron attenuation of samples containing polymers at different concentrations with and without heavy aggregates, the fitting equations were established, and from these the neutron removal coefficients were deduced. In a radiation field of neutrons and gamma rays, the appropriate concentration of polymer and heavy aggregate can be selected to give the optimum total dose attenuation depending on the relative intensities of each type of radiation. This would give much better design flexibility over ordinary concrete. The compressive strength tests performed on mortar and concrete samples showed that their value, in general, decreases as polymer concentration increases and that the polyvinyl chloride mortar showed higher values than the polyethylene mortar. For general construction purposes, the compression strength was considered acceptable in these samples.

  7. Total parenteral nutrition

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000177.htm Total parenteral nutrition To use the sharing features on this page, please enable JavaScript. Total parenteral nutrition (TPN) will help you or your child get ...

  8. Total Knee Replacement

    Science.gov (United States)

    ... following total knee replacement include unlimited walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other ... to the final success of your surgery. To learn more about the full value of total knee ...

  9. Total iron binding capacity

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003489.htm Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...

  10. Anatomic Total Shoulder System

    Medline Plus

    Full Text Available GLOBAL AP ANATOMIC TOTAL SHOULDER SYSTEM METHODIST HOSPITAL PHILADELPHIA, PA April 17, 2008 00:00:10 ANNOUNCER: ... you'll be able to watch a live global AP anatomic total shoulder surgery from Methodist Hospital ...

  11. Innovative IPV from attenuated Sabin poliovirus or newly designed alternative seed strains.

    Science.gov (United States)

    Hamidi, Ahd; Bakker, Wilfried A M

    2012-11-01

    This article gives an overview of the patent literature related to innovative inactivated polio vaccine (i-IPV) based on using Sabin poliovirus strains and newly developed alternative recombinant poliovirus strains. This innovative approach for IPV manufacturing is considered to attribute to the requirement for affordable IPV in the post-polio-eradication era, which is on the horizon. Although IPV is a well-established vaccine, the number of patent applications in this field was seen to have significantly increased in the past decade. Currently, regular IPV appears to be too expensive for universal use. Future affordability may be achieved by using alternative cell lines, alternative virus seed strains, improved and optimized processes, dose sparing, or the use of adjuvants. A relatively short-term option to achieve cost-price reduction is to work on regular IPV, using wild-type poliovirus strains, or on Sabin-IPV, based on using attenuated poliovirus strains. This price reduction can be achieved by introducing efficiency in processing. There are also multiple opportunities to work on dose sparing, for example, by using adjuvants or fractional doses. Renewed interest in this field was clearly reflected in the number and diversity of patent applications. In a later stage, several innovative approaches may become even more attractive, for example the use of recombinant virus strains or even a totally synthetic vaccine. Currently, such work is mainly carried out by research institutes and universities and therefore clinical data are not available. PMID:24236927

  12. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  13. Live attenuated intranasal influenza vaccine.

    Science.gov (United States)

    Esposito, Susanna; Montinaro, Valentina; Groppali, Elena; Tenconi, Rossana; Semino, Margherita; Principi, Nicola

    2012-01-01

    Annual vaccination is the most effective means of preventing and controlling influenza epidemics, and the traditional trivalent inactivated vaccine (TIV) is by far the most widely used. Unfortunately, it has a number of limitations, the most important of which is its poor immunogenicity in younger children and the elderly, the populations at greatest risk of severe influenza. Live attenuated influenza vaccine (LAIV) has characteristics that can overcome some of these limitations. It does not have to be injected because it is administered intranasally. It is very effective in children and adolescents, among whom it prevents significantly more cases of influenza than the traditional TIV. However, its efficacy in adults has not been adequately documented, which is why it has not been licensed for use by adults by the European health authorities. LAIV is safe and well tolerated by children aged > 2 y and adults, but some concerns arisen regarding its safety in younger children and subjects with previous asthma or with recurrent wheezing. Further studies are needed to solve these problems and to evaluate the possible role of LAIV in the annual vaccination of the general population.

  14. Beta attenuation transmission system (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm/sup 2/, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A /sup 90/Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (..mu..P) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined.

  15. Attenuation of diacylglycerol second messengers

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, W.R.; Ganong, B.R.; Bell, R.M.

    1986-05-01

    Diacylglycerol(DAG) derived from phosphatidylinositol activates protein kinase C in agonist-stimulated cells. At least two pathways may contribute to the attenuation of the DAG signal: (1) phosphorylation to phosphatidic acid(PA) by DAG kinase(DGK), and (2) deacylation by DAG and monoacylglycerol lipases. A number of DAG analogs were tested as substrates and inhibitors of partially purified pig brain DGK. Two analogs were potent inhibitors in vitro, 1-monooleoylglycerol(MOG,K/sub I/ = 91 ..mu..M) and diotanoylethyleneglycol (diC/sub 8/EG, K/sub I/ = 58 ..mu..M). These compounds were tested in human platelets. DiC/sub 8/EG inhibited (70 - 100%) (/sup 32/P/sub i/) incorporation into PA in thrombin-stimulated platelets. Under these conditions the DAG signal was somewhat long-lived but was still metabolized, presumably by the lipase pathway. MOG treatment elevated DAG levels up to 4-fold in unstimulated platelets. The DAG formed was in a pool where it did not activate protein kinase C. Thrombin-stimulation of MOG-treated platelets resulted in DAG levels 10-fold higher than control platelets. This appears to be due to the inability of these platelets to metabolize agonist-linked DAG via the lipase pathway. The development of specific inhibitors of DAG kinase and DAG lipase, in conjunction with mass quantification of DAG levels as used here, will provide further insights into the regulation of DAG second messengers.

  16. Stacking coda waves to resolve the scattering and attenuation structure of Southern California

    Science.gov (United States)

    Wang, W.; Shearer, P. M.

    2015-12-01

    Seismic attenuation is caused by two factors, scattering and intrinsic absorption. Charactering the scattering and attenuation properties and the power spectrum of crustal heterogeneity is a fundamental problem for informing strong ground motion estimates at high frequencies, where scattering and attenuation effects are critical. Determining the relative amount of attenuation caused by scattering and intrinsic absorption has been a long-standing interest of seismologists. The wavetrain following the direct body-wave phases is called the coda and is caused by scattered energy. Many studies have analyzed local-event coda to infer crustal and upper-mantle scattering strength and intrinsic attenuation. Here we describe a comprehensive study of coda behavior in Southern California to resolve scattering and intrinsic attenuation structure. First, we apply an envelope-function stacking method to 287,410 seismograms from 6928 geographically dispersed events of M ≥ 1.8 from 1981-2005. The results are presented as spatial averages as a function of distance, source depth, and frequency. Second, we use a Monte Carlo seismic phonon algorithm to simulate the effects of depth-dependent scattering and intrinsic attenuation, which computes scattering probabilities and scattering angles based on theoretical results for random heterogeneity models. This method has the advantage of including both P- and S-wave scattering and is energy conserving even for multiple scattering models. The input 1-D velocity model can be layered to incorporate reflected phases, such as PmP and SmS, to better fit the observations. We will summarize our results for the average scattering and attenuation properties of the southern California crust and the implications for strong ground motion predictions.

  17. Dissenting in Reflective Conversations

    DEFF Research Database (Denmark)

    Bjørn, Pernille; Boulus, Nina

    2011-01-01

    Reflective monitoring of research practices is essential. However, we often lack formal training in the practices of doing action research, and descriptions of actual inquiry practice are seldom included in publications. Our aim is to provide a glimpse of self-reflective practices based on our...

  18. Reflective Practitioner Account

    Institute of Scientific and Technical Information of China (English)

    干青

    2009-01-01

    This article focus on the reflective account of an English teacher learning and teaching in higher education with the British post-graduate certificate program of the Yunnan Agdculture University.As n practitioner for smny years in English learning and teaching for many years,it reflects in four fields.

  19. Earth's Reflection: Albedo

    Science.gov (United States)

    Gillette, Brandon; Hamilton, Cheri

    2011-01-01

    When viewing objects of different colors, you might notice that some appear brighter than others. This is because light is reflected differently from various surfaces, depending on their physical properties. The word "albedo" is used to describe how reflective a surface is. The Earth-atmosphere has a combined albedo of about 30%, a number that is…

  20. Controversy Total War

    OpenAIRE

    Segesser, Daniel Marc

    2014-01-01

    Total war is a controversial term used in the past by politicians, publicists and military officers as well as by computer specialists and academics in the present. Since its conception by French politicians during the First World War in a time of severe crisis (1916/17), it has become a term used by historians and other academics to cover a wide array of elements when looking at wars of the past. A real total war was and is impossible. Elements of total war – total war aims, total methods of...