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Sample records for analisado por xps

  1. Efeito vasomotor após intoxicação aguda com bupivacaína e levobupivacaína via intraperitoneal em ratos, analisado por imagem infravermelha digital

    Directory of Open Access Journals (Sweden)

    Angelo Manoel Grande Carstens

    2011-04-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O estudo do efeito vasomotor dos anestésicos locais (AL é de suma importância para a análise da ocorrência de efeitos cardiotóxicos, neurotóxicos e interações medicamentosas. Com a finalidade de encontrar um fármaco mais seguro do que a bupivacaína racêmica, o presente estudo teve por objetivo a análise por imagem infravermelha digital do efeito vasomotor da intoxicação aguda da bupivacaína e da levobupivacaína via intraperitoneal em ratos. MÉTODO: Utilizaram-se 30 ratos machos da linhagem Wistar, alocados em três grupos (n = 10 e submetidos a uma injeção intraperitoneal de AL. No Grupo C (Controle, foi realizada injeção intraperitoneal de soro fisiológico 0,9% 1 mL. No Grupo B (bupivacaína, injeção intraperitoneal de bupivacaína racêmica a 0,5% (R50-S50, dose de 20 mg.kg-1 de peso. No Grupo L (levobupivacaína, injeção intraperitoneal de levobupivacaína a 0,5%, excesso enantiomérico (S75-R25 em dose de 20 mg.kg-1 de peso. Procedeu-se à filmagem termográfica contínua desde o momento da pré-injeção até 30 minutos após a injeção. Os resultados das filmagens foram analisados em forma gráfica, verificando-se a temperatura máxima de cada rato e a temperatura média do sistema que abrigava o animal. RESULTADOS: Os resultados da análise gráfica revelaram que não houve diferença entre o Grupo L e o Grupo C, e a temperatura média permaneceu estável durante todo o experimento em ambos os grupos. No Grupo B, houve um fenômeno de aumento de temperatura após a injeção intraperitoneal de bupivacaína. CONCLUSÕES: Os resultados demonstraram que o efeito vasomotor da toxicidade aguda da levobupivacaína foi semelhante ao Grupo C com soro fisiológico, por meio de estudos macroscópicos por filmagem digital infravermelha, e que houve alterações vasomotoras (vasoconstrição com a intoxicação por bupivacaína em relação ao Grupo C e em relação ao Grupo L.

  2. Efeito do tratamento térmico na microestrutura, turbostraticidade e superfície de carbono vítreo reticulado analisado por XPS, espalhamento Raman e voltametria cíclica

    OpenAIRE

    Gonçalves,Emerson Sarmento; Rezende,Mirabel Cerqueira; Baldan,Maurício Ribeiro; Ferreira,Neidenêi Gomes

    2009-01-01

    The structural and surface properties of reticulated vitreous carbon (RVC) were discussed as a function of its heat treatment temperature (HTT), for samples produced in the range from 700 to 2000 ºC, using the furfuryl precursor resin. The samples were analyzed by x-ray photoelectron spectroscopy, first and second order Raman scattering as well as electrochemical response. Exploring the material turbostraticity concept, the interdependence between the RVC chemical surface variation and its de...

  3. Efeito do tratamento térmico na microestrutura, turbostraticidade e superfície de carbono vítreo reticulado analisado por XPS, espalhamento Raman e voltametria cíclica Thermal treatment effect on the microstructure, turbostraticity, and surface of reticulated vitreous carbon analyzed by xps, Raman scattering, and cyclic voltammetry

    OpenAIRE

    Emerson Sarmento Gonçalves; Mirabel Cerqueira Rezende; Maurício Ribeiro Baldan; Neidenêi Gomes Ferreira

    2009-01-01

    The structural and surface properties of reticulated vitreous carbon (RVC) were discussed as a function of its heat treatment temperature (HTT), for samples produced in the range from 700 to 2000 ºC, using the furfuryl precursor resin. The samples were analyzed by x-ray photoelectron spectroscopy, first and second order Raman scattering as well as electrochemical response. Exploring the material turbostraticity concept, the interdependence between the RVC chemical surface variation and its de...

  4. Efeito do tratamento térmico na microestrutura, turbostraticidade e superfície de carbono vítreo reticulado analisado por XPS, espalhamento Raman e voltametria cíclica Thermal treatment effect on the microstructure, turbostraticity, and surface of reticulated vitreous carbon analyzed by xps, Raman scattering, and cyclic voltammetry

    Directory of Open Access Journals (Sweden)

    Emerson Sarmento Gonçalves

    2009-01-01

    Full Text Available The structural and surface properties of reticulated vitreous carbon (RVC were discussed as a function of its heat treatment temperature (HTT, for samples produced in the range from 700 to 2000 ºC, using the furfuryl precursor resin. The samples were analyzed by x-ray photoelectron spectroscopy, first and second order Raman scattering as well as electrochemical response. Exploring the material turbostraticity concept, the interdependence between the RVC chemical surface variation and its defects were demonstrated. The influence of heteroatom presence was discussed in the material ordering for HTT lower than 1300 ºC while the graphitization process evolution was also pointed out for HTT higher than 1500 ºC.

  5. Effect of refrigeration systems upon frozen bull sperm viability assessed by computer-assisted sperm analysis and fluorescent probesEfeito de sistemas de refrigeração sobre a viabilidade do sêmen bovino congelado analisado por meio de sistema computadorizado e sondas fluorescentes

    Directory of Open Access Journals (Sweden)

    Frederico Ozanam Papa

    2012-10-01

    Full Text Available Sperm cryopreservation success depends upon the maintenance of spermatozoa fertility potential. Sperm cells must preserve both integrity and functionality of several cell structures. The stabilization phase must allow the exit of water from the sperm cells via osmosis. This study aimed to compare the effect of refrigeration in the commercial refrigerator (CR and the transport/refrigeration box (TRB upon the viability of frozen bull sperm diluted in three different extenders (A, B and C. Ten Nellore bulls, Bos taurus indicus maintained in Artificial Insemination Center were used and the spermatozoa samples was assessed for Plasma Membrane Integrity and CASA evaluation. The stabilization phase (5°C/4 hours was performed in the CR as well as in the TRB, and then samples were exposed to nitrogen vapor during 20 minutes and then plunged into nitrogen. The statistical analysis was done using the variance analysis and the significance level was set at 5%. In the CR the post-thawing parameters for PM and ALH were higher (p O sucesso da criopreservação do sêmen depende da manutenção do potencial de fertilidade dos espermatozoides. Nos espermatozoides deve haver a preservação da integridade e funcionalidade de várias das suas estruturas. A fase de estabilização permite a saída de água dos espermatozoides por osmose. Este estudo tem o objetivo de comparar o efeito da refrigeração em refrigerador comercial (RC e em caixa de transporte refrigerada (CTR na viabilidade do sêmen congelado bovino diluído em três diferentes meios (A, B e C. Dez touros Nelore, Bos taurus indicus mantidos em central de inseminação artificial foram utilizados e as amostras de sêmen analisadas para checar a integridade das membranas plasmáticas e por meio da análise computadorizada (CASA. A fase de estabilização (5°C/4 horas foi realizada em RC e em CTR, sendo as amostras expostas ao vapor de nitrogênio durante 20 minutos e após mergulhadas no nitrog

  6. Comparison between XPS and AES; Comparaison XPS / AES

    Energy Technology Data Exchange (ETDEWEB)

    Barthes-Labrousse, M.G. [Centre National de la Recherche Scientifique (CNRS), 94 - Vitry-sur-Seine (France). Centre d' Etudes de Chimie Metallurgique

    2003-07-01

    This paper gives a short description of the physical principles and main characteristics of Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). Although both techniques have been developed separately both can be found together on the same instrumental equipment. Some differences between these 2 techniques exist: kind of material that can be analysed, resolution, chemical identification... but it is noticed that respective advantages and drawbacks of these methods depend strongly on the kind of material to analyse and what information you look for. (A.C.)

  7. Handbook of Monochromatic XPS Spectra, Semiconductors

    Science.gov (United States)

    Crist, B. Vincent

    2000-10-01

    This handbook is one of three containing an invaluable collection of research grade XPS Spectra. Each handbook concentrates on a specific family of materials (the elements and their native oxides, semiconductors and polymers) and is entirely self-contained. The introductory section to each handbook includes comprehensive information about the XPS instrument used, the materials and the advanced methods used to collect the spectra. Energy resolution settings, instrument characteristics, energy referencing methods, traceability, energy scale calibration details and transmission function are all reported. Among the many valuable features included in each of these handbooks are: ? All spectra were measured by using AlK monochromatic X-rays ? All spectra were collected in a self-consistent manner to maximise data reliability and quality ? All peaks in the wide spectra are fully annotated and accompanied by detailed atom % tables that report BEs for each of the labelled peaks ? Each high-energy resolution spectrum is peak-fitted and accompanied by detailed tables containing binding energies, FWHMs and relative percentages. In this volume 'Semiconductors' are contained XPS Spectra from a wide range of semiconductive materials and related materials, a rare tool for scientists and analysts in this area. Exclusive features of this volume include: ? Binding energies are accurate to +/- 0.08eV ? Charge compensation was done with a flood-gun mesh-screen system ? Valence band spectra document the occupied density of states (DOS) and the fundamental electronic nature of the semi-conductive materials analysed ? Analyses were done: "as received", "freshly fractured in air", "ion etched" and "chemically treated" ? Alphabetically organised by chemical abbreviations for ease of locating each material This handbook is an invaluable reference for materials scientists and electrical engineers in industry, academia and government laboratories interested in the analysis of semiconductors

  8. XPS study of siloxane plasma polymer films

    Czech Academy of Sciences Publication Activity Database

    Bálková, R.; Zemek, Josef; Čech, V.; Vaněk, J.; Přikryl, R.

    174-175, - (2003), s. 1159-1163 ISSN 0257-8972 R&D Projects: GA ČR GA104/00/0708; GA MŠk OC 527.110 Institutional research plan: CEZ:AV0Z1010914 Keywords : radio frequency(RF) * X-ray photoelectron spectroscopy(XPS) * electron spectroscopy for chemical analysis(ESCA) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.410, year: 2003

  9. On calculating intensity from XPS spectra

    International Nuclear Information System (INIS)

    Vegh, Janos

    2006-01-01

    The intensity calculation is the basis for all quantitative applications of electron spectroscopy. Unfortunately, some misinterpreted terms are used and correctly interpreted terms are misused in the overwhelming majority of publications in XPS, including most textbooks as well as accepted and proposed standards. Due to this mistake the number of the detected electrons is given as having dimension of energy (?) and also the formulas for calculating the peak area and its standard deviation are wrong. Since in all other spectroscopic fields the number of the detected particles is dimensionless, continuing this practice leads to isolating XPS from both other measurement sciences and theory, because the measured total intensity in XPS is simply not comparable to the ones derived with other spectroscopic methods or theoretically. Therefore, the basic measuring processes and terms are critically reviewed and their physically correct interpretation is given. This interpretation reveals that the error is hidden in the incorrect interpretation of both the measurement process and the measured quantity. It is shown that through using the correct interpretation both the dimensions of the intensity calculated from electron spectroscopic measurements as well as the formulas related to the intensity and its standard deviation will agree with all other spectroscopic fields

  10. SORCE XPS Level 3 Solar Spectral Irradiance 6-Hour Means V011 (SOR3XPS6) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SORCE XUV Photometer System (XPS) Solar Spectral Irradiance (SSI) 6-Hour Data Product SOR3XPS6 contains solar extreme ultraviolet irradiances in the 0.1 to 27 nm...

  11. Tl Cuprate Superconductors Studied by XPS

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, R. P. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099 (United States); Siegal, M. P. [Sandia National Laboratories, Albuquerque, NM 87185-1421 (United States); Overmyer, D. L. [Sandia National Laboratories, Albuquerque, NM 87185-1421 (United States); Ren, Z. F. [Department of Chemistry, State University of New York, Buffalo, NY 14260-3000 (United States); Lao, J. Y. [Department of Chemistry, State University of New York, Buffalo, NY 14260-3000 (United States); Wang, J. H. [Department of Chemistry, State University of New York, Buffalo, NY 14260-3000 (United States)

    1999-07-01

    XPS measurements on epitaxial thin films of the Tl cuprate superconductors Tl2Ba2CaCu2O8, Tl2Ba2Ca2Cu3O10, and Tl0.78Bi0.22Ba0.4Sr1.6Ca2Cu3O9-{delta} are presented. These data, together with previous measurements in this lab on Tl2Ba2CuO6-{delta} and TlBa2CaCu2O7-{delta}, comprise a comprehensive data set for comparison of Tl cuprates in which the number of Tl-O and Cu-O layers, and hence the chemical and electronic properties, vary. (c) 2000 American Vacuum Society.

  12. Tl Cuprate Superconductors Studied by XPS

    International Nuclear Information System (INIS)

    Vasquez, R. P.; Siegal, M. P.; Overmyer, D. L.; Ren, Z. F.; Lao, J. Y.; Wang, J. H.

    1999-01-01

    XPS measurements on epitaxial thin films of the Tl cuprate superconductors Tl2Ba2CaCu2O8, Tl2Ba2Ca2Cu3O10, and Tl0.78Bi0.22Ba0.4Sr1.6Ca2Cu3O9-δ are presented. These data, together with previous measurements in this lab on Tl2Ba2CuO6-δ and TlBa2CaCu2O7-δ, comprise a comprehensive data set for comparison of Tl cuprates in which the number of Tl-O and Cu-O layers, and hence the chemical and electronic properties, vary. (c) 2000 American Vacuum Society

  13. XPS analysis of boron doped heterofullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, B.; Koetz, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muhr, H.J.; Nesper, R. [ETH Zurich, Zurich (Switzerland)

    1997-06-01

    Boron heterofullerenes were generated through arc-evaporation of doped graphite rods in a helium atmosphere. According to mass spectrometric analysis only mono-substituted fullerenes like C{sub 59}B, C{sub 69}B and higher homologues together with a large fraction of higher undoped fullerenes were extracted and enriched when pyridine was used as the solvent. XPS analysis of the extracts indicated the presence of two boron species with significantly different binding energies. One peak was assigned to borid acid. The second one corresponds to boron in the fullerene cage, which is mainly C{sub 59}B, according to the mass spectrum. This boron is in a somewhat higher oxidation state than that of ordinary boron-carbon compounds. The reported synthesis and extraction procedure opens a viable route for production of macroscopic amounts of these compounds. (author) 2 figs., 1 tab., 7 refs.

  14. XPS investigation of depth profiling induced chemistry

    Science.gov (United States)

    Pratt, Quinn; Skinner, Charles; Koel, Bruce; Chen, Zhu

    2017-10-01

    Surface analysis is an important tool for understanding plasma-material interactions. Depth profiles are typically generated by etching with a monatomic argon ion beam, however this can induce unintended chemical changes in the sample. Tantalum pentoxide, a sputtering standard, and PEDOT:PSS, a polymer that was used to mimic the response of amorphous carbon-hydrogen co-deposits, were studied. We compare depth profiles generated with monatomic and gas cluster argon ion beams (GCIB) using X-ray photoelectron spectroscopy (XPS) to quantify chemical changes. In both samples, monatomic ion bombardment led to beam-induced chemical changes. Tantalum pentoxide exhibited preferential sputtering of oxygen and the polymer experienced significant bond modification. Depth profiling with clusters is shown to mitigate these effects. We present sputtering rates for Ta2O5 and PEDOT:PSS as a function of incident energy and flux. Support was provided through DOE Contract Number DE-AC02-09CH11466.

  15. XPS characterization of naturally aged wood

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, Carmen-Mihaela, E-mail: mihapop@icmpp.ro [Romanian Academy, ' P.Poni' Institute of Macromolecular Chemistry, Physical Chemistry of Polymers Laboratory, 41A Gr. Ghica Voda Alley, Ro 700487, Iasi (Romania); Tibirna, Carmen-Mihaela [Centre de Recherche sur le Bois (CRB), Departement des Sciences du Bois et de la Foret, Laval University, Quebec, G1 V 0A6 (Canada); Vasile, Cornelia [Romanian Academy, ' P.Poni' Institute of Macromolecular Chemistry, Physical Chemistry of Polymers Laboratory, 41A Gr. Ghica Voda Alley, Ro 700487, Iasi (Romania)

    2009-12-15

    Wood deterioration over time (by a simultaneously biological, chemical or physical attack) is an inevitable continuous process in the environment. This process destroys all heritage resulting in a loss of valuable old wooden structures and their properties. What type of deterioration occurs and how these processes impact the wood are important questions that need consideration if old wooden structures are to be studied and properly preserved. X-ray photoelectron spectroscopy (XPS) was employed to analyze the undegraded (sound wood of {approx}6 years) and degraded lime wood ({approx}150 years, {approx}180 years, {approx}250 years) from painting supports, differing in terms of the provenance, conservation status and environmental conditions of storage. Elaborated XPS analysis (comparison of C and O individual spectra, decomposition for each atomic component, calculation of O/C ratio) provided a view of the composition of the sample surfaces analyzed. On the basis of these results, it was confirmed that significant changes occurred in the first period of ageing, the {approx}150 years lime wood sample having the highest percent of the carbon atoms and the lowest percentage of oxygen atoms and, respectively O/C ratio. According to our previous studies (X-ray diffraction, FTIR spectroscopy, analytical pyrolysis combined with gas chromatography/mass spectrometry and ESR-spectroscopy results), these features could be attributed to the fact that hemicelluloses and amorphous cellulose are degraded in time, whereas the crystalline fraction of cellulose decreases more slowly than the amorphous one. Consequently, the observation may be made that lignin is not so easily degraded under the environmental conditions where paintings are frequently exposed.

  16. Application of XPS to study electrocatalysts for fuel cells

    Science.gov (United States)

    Corcoran, C. J.; Tavassol, H.; Rigsby, M. A.; Bagus, P. S.; Wieckowski, A.

    Analysis of the surface is paramount to understanding the reactivity, selectivity, and catalytic ability of substances. In particular, this understanding is required to make an efficient use of the catalytic surfaces in fuel cells. X-ray photoelectron spectroscopy (XPS) allows determination of changes in the electronic structure for different surface preparation and composition based, mainly, on shifts of the binding energies of core-level electrons. It is also an ideal method that allows identification of the surface or near surface species in relation to fuel cell catalysis. However, the fundamental theoretical concepts, which are used to analyze and interpret XPS spectra are sometimes not correctly understood or correctly applied. In this review, we not only report on XPS operational parameters in use for fuel cell electrocatalysis, but, more significantly, we review and provide rigorous definitions of fundamental concepts used to understand XPS spectra, including the separation of initial and final state effects and the relaxation of valence electrons to screen core-holes. An additional direction of our review is to show the relationships between XPS binding energy shifts and XPS satellite structure with chemical bonding and chemical interactions. However, our primary concern is to provide reviews of representative cases of the application of XPS to solving fuel cell and electrocatalysis-related problems, highlighting progress in this laboratory. We begin with descriptions of essential issues in fuel cell science and with a review of key concepts of XPS. Then, we briefly report on the XPS instrumentation, after which, studies of fundamental importance to electrochemical processes are reviewed. This review includes an overview of complex organic and biological systems in relation to fuel cell electrocatalysis (probed via XPS). We conclude with a discussion of modern developments in XPS methodology.

  17. XPS study of palladium sensitized nano porous silicon thin film

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 33; Issue 6. XPS study of palladium sensitized nano porous silicon thin ... To stabilize the material PS surface was modified by a simple and low cost chemical method using PdCl2 solution at room temperature. X-ray photoelectron spectroscopy (XPS) was performed to ...

  18. Visita ??ntima na unidade prisional feminina de regime fechado e provis??rio de Palmas/TO: sentidos e significados analisados sob o enfoque fenomenol??gico

    OpenAIRE

    Paro, Marcelo Laurito

    2016-01-01

    Relat??rio t??cnico de pesquisa aplicada que teve por objetivo analisar o fen??meno da visita ??ntima na Unidade Prisional Feminina de Palmas/TO, sob a perspectiva das pr??prias mulheres encarceradas. O m??todo fenomenol??gico utilizado mostrou-se o mais adequado aos objetivos propostos de desvelar e revelar os sentidos e significados atribu??dos pelas presidi??rias ?? visita. A coleta de dados deu-se por question??rio semiestruturado e entrevista aberta com uso de pergunta dis...

  19. XPS investigations of tribofilms formed on CrN coatings

    Energy Technology Data Exchange (ETDEWEB)

    Mandrino, Djordje, E-mail: djordje.mandrino@imt.si; Podgornik, Bojan

    2017-02-28

    Highlights: • Formation of tribofilms from lubricant additives on CrN surfaces during tribological contact confirmed by XPS. • Chemistry & chemical state of tribofilms obtained by XPS. • Thin sulphate film forms at the top of sulphide tribofilm. • Final type of sulphide in tribolayer depends on additive chemistry and testing temperature. - Abstract: Action of lubrication additives in the case of uncoated steel surfaces, including the type and mechanism of tribofilm formation is well known and understood. However, contact type of tribofilms which might form under the tribological contact between CrN coated surfaces, remains more or less unexplored. The aim of this investigation was to study the type of tribofilms formed on the CrN coated steel samples subjected to lubricated reciprocating sliding contact under different contact conditions Contact surface and tribofilms formed were studied by X-ray Photoelectron Spectroscopy (XPS). Sample surfaces were first imaged by Scanning Electron Microscopy (SEM) to determine areas of tribofilm formation as well as areas not affected by tribological contact. In these areas survey and high resolution (HR) XPS measurements were performed to obtain information about surface chemistry and oxidation states of the constituent elements. It was found that differences between different samples, observed by the XPS measurements, may reflect differences in chemistry of tribofilms formed under different contact conditions.

  20. Characterization of fossil remains using XRF, XPS and XAFS spectroscopies

    International Nuclear Information System (INIS)

    Zougrou, I M; Katsikini, M; Pinakidou, F; Paloura, E C; Brzhezinskaya, M; Papadopoulou, L; Vlachos, E; Tsoukala, E

    2016-01-01

    Synchrotron radiation micro-X-Ray Fluorescence (μ-XRF), X-ray photoelectron (XPS) and X-ray Absorption Fine Structure (XAFS) spectroscopies are applied for the study of paleontological findings. More specifically the costal plate of a gigantic terrestrial turtle Titanochelon bacharidisi and a fossilized coprolite of the cave spotted hyena Crocuta crocuta spelaea are studied. Ca L 2,3 -edge NEXAFS and Ca 2p XPS are applied for the identification and quantification of apatite and Ca containing minerals. XRF mapping and XAFS are employed for the study of the spatial distribution and speciation of the minerals related to the deposition environment. (paper)

  1. Quantitative XPS analysis of thin iron-oxide films

    DEFF Research Database (Denmark)

    Graat, P.C.J.; Somers, Marcel A. J.

    1997-01-01

    Over the last decade Tougaard et al. (see e.g. Ref. 1) provided a formalism to calculate the contribution of inelastically scattered electrons to an XPS or AES spectrum. In that formalism it was assumed that the signal electrons move along straight lines to the surface. Recently, Werner et al. pr...

  2. XPS studies of the oxide formed on pure Ti

    International Nuclear Information System (INIS)

    Cremery, P.; David, D.; Beranger, G.; Oviedo, C.; Garcia, E.A.

    1980-01-01

    The XPS technique was used to study titanium samples oxidized at 200 ton of pure oxigen at different times and temperatures with the aim of producing variable oxide thicknesses. The thicknesses of different oxigen layers were determined by the nuclear reaction O 16 (d,p) O 17 *. (author) [pt

  3. XPS analysis of nanostructured materials and biological surfaces

    International Nuclear Information System (INIS)

    Baer, D.R.; Engelhard, M.H.

    2010-01-01

    This paper examines the types of information that XPS can provide about a variety of nanostructured materials. Although it is sometimes not considered a 'nanoscale analysis method,' XPS can provide a great deal of information about elemental distributions, layer or coating structure and thicknesses, surface functionality, and even particles sizes on the 1-20 nm scale for sample types that may not be readily analyzed by other methods. This information is important for both synthetic nanostructured or nanosized materials and a variety of natural materials with nanostructure. Although the links between nanostructure materials and biological systems may not at first be obvious, many biological molecules and some organisms are the sizes of nanoparticles. The nanostructure of cells and microbes plays a significant role in how they interact with their environment. The interaction of biomolecules with nanoparticles is important for medical and toxicity studies. The interaction of biomolecules is important for sensor function and many nanomaterials are now the active elements in sensors. This paper first discusses how nanostructures influences XPS data as a part of understanding how simple models of sample structure and data analysis can be used to extract information about the physical and chemical structures of the materials being analyzed. Equally important, aspects of sample and analysis limitations and challenges associated with understanding nanostructured materials are indicated. Examples of the application of XPS to nanostructured and biological systems and materials are provided.

  4. XPS quantification of the hetero-junction interface energy

    International Nuclear Information System (INIS)

    Ma, Z.S.; Wang Yan; Huang, Y.L.; Zhou, Z.F.; Zhou, Y.C.; Zheng Weitao; Sun, Chang Q.

    2013-01-01

    Highlights: ► Quantum entrapment or polarization dictates the performance of dopant, impurity, interface, alloy and compounds. ► Interface bond energy, energy density, and atomic cohesive energy can be determined using XPS and our BOLS theory. ► Presents a new and reliable method for catalyst design and identification. ► Entrapment makes CuPd to be a p-type catalyst and polarization derives AgPd as an n-type catalyst. - Abstract: We present an approach for quantifying the heterogeneous interface bond energy using X-ray photoelectron spectroscopy (XPS). Firstly, from analyzing the XPS core-level shift of the elemental surfaces we obtained the energy levels of an isolated atom and their bulk shifts of the constituent elements for reference; then we measured the energy shifts of the specific energy levels upon interface alloy formation. Subtracting the referential spectrum from that collected from the alloy, we can distil the interface effect on the binding energy. Calibrated based on the energy levels and their bulk shifts derived from elemental surfaces, we can derive the bond energy, energy density, atomic cohesive energy, and free energy at the interface region. This approach has enabled us to clarify the dominance of quantum entrapment at CuPd interface and the dominance of polarization at AgPd and BeW interfaces, as the origin of interface energy change. Developed approach not only enhances the power of XPS but also enables the quantification of the interface energy at the atomic scale that has been an issue of long challenge.

  5. SORCE XPS Level 3 Solar Spectral Irradiance 6-Hour Means V010

    Data.gov (United States)

    National Aeronautics and Space Administration — The SORCE XUV Photometer System (XPS) Solar Spectral Irradiance (SSI) 6-Hour Data Product SOR3XPS6 contains solar XUV irradiances in the 0.1 to 27 nm range, as well...

  6. Elemental and Chemical State Analysis, XPS, for In-Situ Materials Analysis on Mars, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovation is the design of a monochromatic x-ray source to be used in a mission compatible XPS spectrometer. Existing x-ray sources for XPS are large, require...

  7. Applications Performance on NAS Intel Paragon XP/S - 15#

    Science.gov (United States)

    Saini, Subhash; Simon, Horst D.; Copper, D. M. (Technical Monitor)

    1994-01-01

    The Numerical Aerodynamic Simulation (NAS) Systems Division received an Intel Touchstone Sigma prototype model Paragon XP/S- 15 in February, 1993. The i860 XP microprocessor with an integrated floating point unit and operating in dual -instruction mode gives peak performance of 75 million floating point operations (NIFLOPS) per second for 64 bit floating point arithmetic. It is used in the Paragon XP/S-15 which has been installed at NAS, NASA Ames Research Center. The NAS Paragon has 208 nodes and its peak performance is 15.6 GFLOPS. Here, we will report on early experience using the Paragon XP/S- 15. We have tested its performance using both kernels and applications of interest to NAS. We have measured the performance of BLAS 1, 2 and 3 both assembly-coded and Fortran coded on NAS Paragon XP/S- 15. Furthermore, we have investigated the performance of a single node one-dimensional FFT, a distributed two-dimensional FFT and a distributed three-dimensional FFT Finally, we measured the performance of NAS Parallel Benchmarks (NPB) on the Paragon and compare it with the performance obtained on other highly parallel machines, such as CM-5, CRAY T3D, IBM SP I, etc. In particular, we investigated the following issues, which can strongly affect the performance of the Paragon: a. Impact of the operating system: Intel currently uses as a default an operating system OSF/1 AD from the Open Software Foundation. The paging of Open Software Foundation (OSF) server at 22 MB to make more memory available for the application degrades the performance. We found that when the limit of 26 NIB per node out of 32 MB available is reached, the application is paged out of main memory using virtual memory. When the application starts paging, the performance is considerably reduced. We found that dynamic memory allocation can help applications performance under certain circumstances. b. Impact of data cache on the i860/XP: We measured the performance of the BLAS both assembly coded and Fortran

  8. XPS Studies of LSCF Interfaces after Cell Testing

    Directory of Open Access Journals (Sweden)

    Gianfranco DiGiuseppe

    2018-01-01

    Full Text Available The motivation of this investigation is to explore the possibility of using the depth profile capability of XPS to study interfaces after SOFC button cell testing. The literature uses XPS to study various cathode materials but has devoted little to the understanding of various cathode interfaces especially after testing. In this work, an SOFC button cell is first tested, and then, the LSCF cathode, barrier layer, and electrolyte are sputtered away to study the behavior of different interfaces. This work has shown that some elements have moved into other layers of the SOFC cell. It is argued that the migration of the elements is partly due to a redeposition mechanism after atoms are sputtered away, while the rest is due to interdiffusion between the SDC and YSZ layers. However, additional work is needed to better understand the mechanism by which atoms move around at different interfaces. The cell electrochemical performance is also discussed in some details but is not the focus.

  9. Speciation of uranium after microbial action by XANES and XPS

    International Nuclear Information System (INIS)

    Dodge, C.J.; Francis, A.J.; Lu, F.; Halada, G.P.; Kagwade, S.V.; Clayton, C.R.

    1993-01-01

    The speciation of radionuclides and toxic metals in wastes subjected to microbial action is important in determining the extent of stabilization in a disposal environment. As part of an ongoing study, we investigated the reduction of uranium by a Clostridium sp. using X-ray absorption neat edge spectroscopy (XANES) at the National Synchrotron Light Source (NSLS) and X-ray photoelectron spectroscopy (XPS). XPS analysis of uranyl acetate containing hexavalent uranium exhibited a binding energy of 382.0eV at the U 4f 7/2 peak. The sample incubated in the presence of bacteria was shifted to lower binding energy (380.6eV), confirming the reduction of U 6+ to U 4+ at the bacterial surface. XANES analysis, using an electron yield detector, was performed at the M v absorption edge (3d-->5f). The absorption peak energy of the sample exhibited a shift from 3551.1eV to 3550.1eV which is higher than uranium metal (3549.6eV ) but lower than U 4+ (3550.4eV). This indicates the presence of U 3+ which is probably located beneath the surface within the biomass. Anaerobic bacterial treatment of wastes containing uranyl ion can result in the stabilization of uranium

  10. Secondary electron measurement and XPS characterization of NEG coatings

    International Nuclear Information System (INIS)

    Sharma, R. K.; Sinha, Atul K.; Gupta, Nidhi; Nuwad, J.; Jagannath,; Gadkari, S. C.; Singh, M. R.; Gupta, S. K.

    2014-01-01

    Ternary alloy coatings of IVB and VB materials provide many of benefits over traditional material surfaces such as creation of extreme high vacuum(XHV), lower secondary electron yield(SEY), low photon desorption coefficient. XHV (pressure −10 mbar) is very useful to the study of surfaces of the material in as it is form, high energy particle accelerators(LHC, Photon Factories), synchrotrons (ESRF, Ellectra) etc.. Low secondary electron yield leads to very low multi-pacting utilizes to increase beam life time. In this paper preparation of the coatings and a study of secondary electron yield measurement after heating at different temperatures has been shown also results of their surface characterization based on shift in binding energy has been produced using the surface techniques XPS. Stoichiometry of the film was measured by Energy dispersive x-ray analysis (EDX)

  11. The equivalent width as a figure of merit for XPS narrow scans

    International Nuclear Information System (INIS)

    Singh, Bhupinder; Velázquez, Daniel; Terry, Jeff; Linford, Matthew R.

    2014-01-01

    Highlights: • We introduce a new figure of merit for XPS narrow scans: the equivalent width (EW XPS ). • EW XPS is less subjective and involves lesser user bias than traditional peak fitting. • EW XPS is responsive to changes in chemical states of materials. • EW XPS could be used for quality control and comparing spectra from similar samples. • EW XPS has the potential to be part of an expert software system for machine interpretation of spectra. - Abstract: X-ray Photoelectron Spectroscopy (XPS) is a widely used surface analytical tool that provides information about the near surface regions of materials. And while indispensable for XPS data analysis, peak fitting of narrow scans is often a fairly subjective exercise. Herein we introduce the equivalent width (EW) as an additional and less subjective figure of merit for XPS narrow scans. We believe that this parameter will prove particularly useful for analyzing series of similar or nominally identical spectra, perhaps as a component of an expert software system for the machine interpretation of spectra. It also appears to be useful, shedding light on the chemical state of materials, when additional information about a sample is known. The EW XPS is simply defined as the area of a narrow scan divided by the height of the maximum of its peak envelope. To limit any ambiguity in EW XPS for a series of spectra, we may also list the peak position of the maximum of the envelope (PE max ). The potential usefulness and limitations of the EW XPS and PE max parameters are demonstrated by their application to the narrow scans of: (i) four sets of ozone-treated carbon nanotubes (EW XPS ∼ 2.11–2.16 eV for a Shirley background, and up to 2.88 eV for no background, PE max ∼ 284.4–284.5 eV), (ii) a series of silicon wafers with different oxide thicknesses (EW XPS ∼ 1.5–2.8 eV, PE max ∼ 99–103 eV), (iii) hydrogen-terminated silicon before and after derivatization with pentyl groups, and after annealing of

  12. XPS STRUCTURE ANALYSIS OF TiN/TiC BILAYERS PRODUCED BY PULSED VACUUM ARC DISCHARGE

    Directory of Open Access Journals (Sweden)

    ELISABETH RESTREPO PARRA

    2010-01-01

    Full Text Available se crecieron bicapas de TiN/TiC sobre sustratos de acero inoxidable 304 usando un sistema de deposición física de vapor asistida por plasma en forma de arco pulsado a dos diferentes temperaturas del sustrato (50º C y150º C. Para el análisis de la composición química se empleó la técnica de la espectroscopía de fotoelectrones de rayos X (XPS. Se observó el comportamiento de las líneas Ti2p, N1s y C1s. Los análisis de energía de enlace confirmaron la conformación de TiN y TiC. Los picos C1s y Ti2p sufrieron un corrimiento a medida que se incrementó el tiempo de esputtering, revelando contaminación debido a la presencia de hidrocarburos. Además, los perfiles de profundidad de las bicapas de TiN/TiC mostraron que las películas crecidas a una temperatura de 150 ° C tienen una capa de TiN más gruesa que las muestras crecidas a 50º C. El nitrógeno se difundió en la capa de TiC y el carbón en la capa de TiN para ambas temperaturas.

  13. Studies of irradiated zircaloy fuel sheathing using XPS

    International Nuclear Information System (INIS)

    Chan, P.K.; Irving, K.G.; Hocking, W.H.; Duclos, A.M.; Gerwing, A.F.

    1995-01-01

    The preliminary results reported here support the hypothesis that CANLUB graphite coating reduces the rate at which oxygen can react with fuel sheathing. X-ray photoelectron spectroscopic (XPS) characterization of Zircaloy sheathing obtained from extended-burnup Bruce-type elements (BDL-406-XY (555 MW.h/kgU) and BDL-406-AAH (731 MW.h/kgU)) irradiated in NRU indicates that CANLUB may reduce fuel sheath oxidation, and hence that fission-liberated oxygen may remain in the fuel. Chemical shifts in the Zr 3d spectra suggest that a stoichiometric (ZrO 2 ) oxide film was formed only on Zircaloy in direct contact with fuel. Particulate fuel adhering to the sheath was also determined to be systematically more oxidized on surfaces with CANLUB than on those without it. The unique association of tin on sheathing specimens with the non-CANLUB-coated specimens might also suggest that the tin had segregated from the sheathing. It must be emphasized that further experiments are required to better define the effect of CANLUB on fuel oxidation. (author). 14 refs., 1 tab., 3 figs

  14. An XPS study on ruthenium compounds and catalysts

    International Nuclear Information System (INIS)

    Bianchi, C.L.; Ragaini, V.; Cattania, M.G.

    1991-01-01

    The binding energy (BE) of the relevant peaks of several ruthenium compounds have been measured with a monochromatic small spot XPS. The BE of the 3d 5/2 level of ruthenium is in the range 279.91-282.88 eV. The variation of BE is due either to the variation of the oxidation state or to the different counter-ion. A series of catalysts with varying amounts of ruthenium supported on alumina and prepared using different precursors was also analyzed. The presence of more ruthenium species other than the metal was observed. On the basis of the values previously obtained on unsupported compounds, the species with higher BE were assigned to oxides. On all the samples prepared from RuCl 3 , an additional peak at a very high BE (283.79 eV) has been observed. This peak is related to the presence of chlorine on the surface: it is suggested that it is related to a charge transfer interaction. The influence of this species on the CO reactivity in the Fischer-Tropsch reaction is discussed. (orig.)

  15. X-ray photoelectron spectroscopy (XPS) studies of rhenium catalyst

    International Nuclear Information System (INIS)

    Mohd Ambar Yarmo; Che Seman Mahmood

    2000-01-01

    Rhenium oxide on alumina (Re 2 O 7 /Al 2 O 3 ) is a very active catalyst system for olefin metathesis reaction. The catalyst can be prepared by wet impregnation of ammonium perrhenate (NH 4 ReO 4 ) solution onto alumina (γ-AI 2 O 3 ) support followed by drying and calcination in air. In this study, rhenium catalysts at different treatment conditions namely active, non-active and during propylene metathesis reaction were investigated using X-ray photoelectron spectroscopy (XPS) technique. Analysis of O 1s , photoelectron peak shows that some chemical interaction between rhenium oxides and the support have been established through Re-O-Al linkage. Analysis of Re 4f7/2 photoelectron peak by using a systematic deconvolution procedure, shows that the metal was in a mixed and varied oxidation states from Re(IV) to Re(VII) depending on their treatment condition. The presence of the metal-carbene complex, the reaction intermediate, could possibly be observed by analysing the C 1s , photoelectron peak. However, a much higher vacuum (i.e. 10 -10 - 10 -11 torr) is needed in the spectroscopy system in order to have the improved detection sensitivity. (Author)

  16. Sub-nanometer resolution XPS depth profiling: Sensing of atoms

    Energy Technology Data Exchange (ETDEWEB)

    Szklarczyk, Marek, E-mail: szklarcz@chem.uw.edu.pl [Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw (Poland); Shim-Pol, ul. Lubomirskiego 5, 05-080 Izabelin (Poland); Macak, Karol; Roberts, Adam J. [Kratos Analytical Ltd, Wharfside, Trafford Wharf Road, Manchester, M17 1GP (United Kingdom); Takahashi, Kazuhiro [Kratos XPS Section, Shimadzu Corp., 380-1 Horiyamashita, Hadano, Kanagawa 259-1304 (Japan); Hutton, Simon [Kratos Analytical Ltd, Wharfside, Trafford Wharf Road, Manchester, M17 1GP (United Kingdom); Głaszczka, Rafał [Shim-Pol, ul. Lubomirskiego 5, 05-080 Izabelin (Poland); Blomfield, Christopher [Kratos Analytical Ltd, Wharfside, Trafford Wharf Road, Manchester, M17 1GP (United Kingdom)

    2017-07-31

    Highlights: • Angle resolved photoelectron depth profiling of nano thin films. • Sensing atomic position in SAM films. • Detection of direction position of adsorbed molecules. - Abstract: The development of a method capable of distinguishing a single atom in a single molecule is important in many fields. The results reported herein demonstrate sub-nanometer resolution for angularly resolved X-ray photoelectron spectroscopy (ARXPS). This is made possible by the incorporation of a Maximum Entropy Method (MEM) model, which utilize density corrected electronic emission factors to the X-ray photoelectron spectroscopy (XPS) experimental results. In this paper we report on the comparison between experimental ARXPS results and reconstructed for both inorganic and organic thin film samples. Unexpected deviations between experimental data and calculated points are explained by the inaccuracy of the constants and standards used for the calculation, e.g. emission factors, scattering intensity and atomic density through the studied thickness. The positions of iron, nitrogen and fluorine atoms were determined in the molecules of the studied self-assembled monolayers. It has been shown that reconstruction of real spectroscopic data with 0.2 nm resolution is possible.

  17. Effects of XPS operational parameters on investigated sample surfaces

    International Nuclear Information System (INIS)

    Mrad, O.; Ismail, I.

    2013-04-01

    In this work, we studied the effects of the operating conditions of the xray photoelectron spectroscopy analysis technique (XPS) on the investigated samples. Firstly, the performances of the whole system have been verified as well as the accuracy of the analysis. Afterwards, the problem of the analysis of insulating samples caused by the charge buildup on the surface has been studied. The use of low-energy electron beam (<100 eV) to compensate the surface charge has been applied. The effect of X-ray on the samples have been assessed and was found to be nondestructive within the analysis time. The effect of low- and high-energy electron beams on the sample surface have been investigated. Highenergy electrons were found to have destructive effect on organic samples. The sample heating procedure has been tested and its effect on the chemical stat of the surface was followed. Finally, the ion source was used to determine the elements distribution and the chemical stat of different depths of the sample. A method has been proposed to determine these depths (author).

  18. The assessment of metal surface cleanliness by XPS

    CERN Document Server

    Scheuerlein, C

    2006-01-01

    The most commonly used quantity to characterize surface cleanliness through X-ray photoemission spectroscopy (XPS) measurements is the so-called relative atomic surface concentration of carbon (at.% C). We have investigated the relationship between at.% C values and the C 1s peak area on Cu and we find a nearly linear behaviour in the range 15–80 at.% C. Correction factors for the measured at.% C values that enable a comparison of the cleanliness level of different materials, notably Cu, Al and stainless steel, have been determined experimentally. The influence of the storage time and method on the degree of re-contamination of initially clean Cu has been examined. The carbon contamination on clean metallic Cu increases abruptly to some 20 at.% C upon air exposure and continues to increase with storage time in air. Storage in polymer bags can lead to up to 70 at.% C after 1 month, whereas storage in aluminium foil can preserve an acceptable surface cleanliness for a similar storage time.

  19. XPS Protocol for the Characterization of Pristine and Functionalized Single Wall Carbon Nanotubes

    Science.gov (United States)

    Sosa, E. D.; Allada, R.; Huffman, C. B.; Arepalli, S.

    2009-01-01

    Recent interest in developing new applications for carbon nanotubes (CNT) has fueled the need to use accurate macroscopic and nanoscopic techniques to characterize and understand their chemistry. X-ray photoelectron spectroscopy (XPS) has proved to be a useful analytical tool for nanoscale surface characterization of materials including carbon nanotubes. Recent nanotechnology research at NASA Johnson Space Center (NASA-JSC) helped to establish a characterization protocol for quality assessment for single wall carbon nanotubes (SWCNTs). Here, a review of some of the major factors of the XPS technique that can influence the quality of analytical data, suggestions for methods to maximize the quality of data obtained by XPS, and the development of a protocol for XPS characterization as a complementary technique for analyzing the purity and surface characteristics of SWCNTs is presented. The XPS protocol is then applied to a number of experiments including impurity analysis and the study of chemical modifications for SWCNTs.

  20. SORCE XPS Level 3 Solar Spectral Irradiance Daily Means V010

    Data.gov (United States)

    National Aeronautics and Space Administration — The SORCE XUV Photometer System (XPS) Solar Spectral Irradiance (SSI) Daily Data Product SOR3XPSD contains solar XUV irradiances in the 0.1 to 27 nm range, as well...

  1. Elemental and Chemical State Analysis, XPS, for In-Situ Materials Analysis on Mars, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective in this project is the development of a monochromatic x-ray source for a small x-ray Photoelectron Spectrometer (XPS) suitable for NASA missions. This...

  2. Combined PIXE and XPS analysis on republican and imperial Roman coins

    International Nuclear Information System (INIS)

    Dacca, A.; Prati, P.; Zucchiatti, A.; Lucarelli, F.; Mando, P.A.; Gemme, G.; Parodi, R.; Pera, R.

    2000-01-01

    A combined PIXE and XPS analysis has been performed on a few Roman coins of the republican and imperial age. The purpose was to investigate via XPS the nature and extent of patina in order to be capable of extracting PIXE data relative to the coins bulk. The inclusion of elements from the surface layer, altered by oxidation and inclusion, is a known source of uncertainty in PIXE analyses of coins, performed to assess the composition and the provenance

  3. A combined QCM and XPS investigation of asphaltene adsorption on metal surfaces.

    Science.gov (United States)

    Rudrake, Amit; Karan, Kunal; Horton, J Hugh

    2009-04-01

    To investigate asphaltene-metal interactions, a combined quartz crystal microbalance (QCM) and X-ray photoelectron spectroscopy (XPS) study of asphaltene adsorption on a gold surface was conducted. Adsorption experiments were conducted at 25 degrees C with solutions of asphaltenes in toluene at concentrations ranging from 50 to 1500 ppm. QCM measurements yielded information on the kinetics of adsorption and further assessment of the data allowed the estimation of equilibrium adsorption levels. XPS analysis of adsorbed and bulk asphaltene demonstrated the presence of carboxylic, thiophenic, sulfide, pyridinic and pyrrolic type functional groups. The intensity of the main carbon (C-H) peak was related to surface coverage of adsorbed asphaltene as a function of asphaltene concentration by a simple mathematical model. The mass adsorption data from the QCM experiments also allowed estimation of the surface coverage, which was compared to those from XPS analyses. Surface coverage estimates as a function of asphaltene concentration could be described by a Langmuir (type-I) isotherm. The free energy of asphaltene adsorption was estimated to be -26.8+/-0.1 and -27.3+/-0.1 kJ/mol from QCM and XPS data, respectively assuming asphaltene molar mass of 750 g/gmol. QCM and XPS data was also analyzed to estimate adsorbed layer thickness after accounting for surface coverage. The thickness of the adsorbed asphaltene estimated from both XPS and QCM data analyses ranged from 6-8 nm over the entire range of adsorption concentrations investigated.

  4. Versatile technique for assessing thickness of 2D layered materials by XPS

    Science.gov (United States)

    Zemlyanov, Dmitry Y.; Jespersen, Michael; Zakharov, Dmitry N.; Hu, Jianjun; Paul, Rajib; Kumar, Anurag; Pacley, Shanee; Glavin, Nicholas; Saenz, David; Smith, Kyle C.; Fisher, Timothy S.; Voevodin, Andrey A.

    2018-03-01

    X-ray photoelectron spectroscopy (XPS) has been utilized as a versatile method for thickness characterization of various two-dimensional (2D) films. Accurate thickness can be measured simultaneously while acquiring XPS data for chemical characterization of 2D films having thickness up to approximately 10 nm. For validating the developed technique, thicknesses of few-layer graphene (FLG), MoS2 and amorphous boron nitride (a-BN) layer, produced by microwave plasma chemical vapor deposition (MPCVD), plasma enhanced chemical vapor deposition (PECVD), and pulsed laser deposition (PLD) respectively, were accurately measured. The intensity ratio between photoemission peaks recorded for the films (C 1s, Mo 3d, B 1s) and the substrates (Cu 2p, Al 2p, Si 2p) is the primary input parameter for thickness calculation, in addition to the atomic densities of the substrate and the film, and the corresponding electron attenuation length (EAL). The XPS data was used with a proposed model for thickness calculations, which was verified by cross-sectional transmission electron microscope (TEM) measurement of thickness for all the films. The XPS method determines thickness values averaged over an analysis area which is orders of magnitude larger than the typical area in cross-sectional TEM imaging, hence provides an advanced approach for thickness measurement over large areas of 2D materials. The study confirms that the versatile XPS method allows rapid and reliable assessment of the 2D material thickness and this method can facilitate in tailoring growth conditions for producing very thin 2D materials effectively over a large area. Furthermore, the XPS measurement for a typical 2D material is non-destructive and does not require special sample preparation. Therefore, after XPS analysis, exactly the same sample can undergo further processing or utilization.

  5. Round robin: Quantitative lateral resolution of PHI XPS microprobes Quantum 2000/Quantera SXM

    International Nuclear Information System (INIS)

    Scheithauer, Uwe; Kolb, Max; Kip, Gerard A.M.; Naburgh, Emile; Snijders, J.H.M.

    2016-01-01

    Highlights: • The quantitative lateral resolution of 7 PHI XPS microprobes has been estimated in a round robin. • An ellipsoidally shaped quartz crystal monochromatizes the Alkα radiation and refocuses it from the Al anode to the sample surface. • The long tail contributions of the X-ray beam intensity distribution were measured using a new and innovative approach. • This quantitative lateral resolution has a significantly larger value than the nominal X-ray beam diameter. • The quantitative lateral resolution follows a trend in time: The newer the monochromator so much the better the quantitative lateral resolution. - Abstract: The quantitative lateral resolution is a reliable measure for the quality of an XPS microprobe equipped with a focused X-ray beam. It describes the long tail contributions of the X-ray beam intensity distribution. The knowledge of these long tail contributions is essential when judging on the origin of signals of XPS spectra recorded on small-sized features. In this round robin test the quantitative lateral resolution of 7 PHI XPS microprobes has been estimated. As expected, the quantitative lateral resolution has significantly larger values than the nominal X-ray beam diameter. The estimated values of the quantitative lateral resolution follow a trend in time: the newer the monochromator of an XPS microprobe so much the better the quantitative lateral resolution.

  6. Round robin: Quantitative lateral resolution of PHI XPS microprobes Quantum 2000/Quantera SXM

    Energy Technology Data Exchange (ETDEWEB)

    Scheithauer, Uwe, E-mail: scht.uhg@googlemail.com [82008 Unterhaching (Germany); Kolb, Max, E-mail: max.kolb@airbus.com [Airbus Group Innovations, TX2, 81663 Munich (Germany); Kip, Gerard A.M., E-mail: G.A.M.Kip@utwente.nl [Universiteit Twente, MESA+ Nanolab, Postbus 217, 7500AE Enschede (Netherlands); Naburgh, Emile, E-mail: e.p.naburgh@philips.com [Materials Analysis, Philips Innovation Services, High Tech Campus 11, 5656 AE Eindhoven (Netherlands); Snijders, J.H.M., E-mail: j.h.m.snijders@philips.com [Materials Analysis, Philips Innovation Services, High Tech Campus 11, 5656 AE Eindhoven (Netherlands)

    2016-07-15

    Highlights: • The quantitative lateral resolution of 7 PHI XPS microprobes has been estimated in a round robin. • An ellipsoidally shaped quartz crystal monochromatizes the Alkα radiation and refocuses it from the Al anode to the sample surface. • The long tail contributions of the X-ray beam intensity distribution were measured using a new and innovative approach. • This quantitative lateral resolution has a significantly larger value than the nominal X-ray beam diameter. • The quantitative lateral resolution follows a trend in time: The newer the monochromator so much the better the quantitative lateral resolution. - Abstract: The quantitative lateral resolution is a reliable measure for the quality of an XPS microprobe equipped with a focused X-ray beam. It describes the long tail contributions of the X-ray beam intensity distribution. The knowledge of these long tail contributions is essential when judging on the origin of signals of XPS spectra recorded on small-sized features. In this round robin test the quantitative lateral resolution of 7 PHI XPS microprobes has been estimated. As expected, the quantitative lateral resolution has significantly larger values than the nominal X-ray beam diameter. The estimated values of the quantitative lateral resolution follow a trend in time: the newer the monochromator of an XPS microprobe so much the better the quantitative lateral resolution.

  7. Surface functional group characterization using chemical derivatization X-ray photoelectron spectroscopy (CD-XPS)

    Energy Technology Data Exchange (ETDEWEB)

    Jagst, Eda

    2011-03-18

    Chemical derivatization - X-ray photolectron spectroscopy (CD-XPS) was applied successfully in order to determine different functional groups on thin film surfaces. Different amino group carrying surfaces, prepared by spin coating, self-assembly and plasma polymerization, were successfully investigated by (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Amino groups were derivatized with the widely used primary amino group tags, pentafluorobenzaldehyde (PFB) and 4-(trifluoromethyl)-benzaldehyde (TFBA), prior to analysis. Primary amino group quantification was then carried out according to the spectroscopical data. Self-assembled monolayers (SAMs) of different terminal groups were prepared and investigated with XPS and spectra were compared with reference surfaces. An angle resolved NEXAFS measurement was applied to determine the orientation of SAMs. Plasma polymerized allylamine samples with different duty cycle, power and pressure values were prepared in order to study the effects of external plasma parameters on the primary amino group retention. CD-XPS was used to quantify the amino groups and experiments show, that the milder plasma conditions promote the retention of amino groups originating from the allylamine monomer. An interlaboratory comparison of OH group determination on plasma surfaces of polypropylene treated with oxygen plasma, was studied. The surfaces were investigated with XPS and the [OH] amount on the surfaces was calculated. (orig.)

  8. An XPS study of the adsorption of lead on goethite (α-FeOOH)

    Science.gov (United States)

    Abdel-Samad, Hesham; Watson, Philip R.

    1998-10-01

    The adsorption behavior of divalent metal ions on amphoteric surface hydroxyl groups of metal oxides is an important factor in the transport of subsurface environmental pollutants. We have studied the adsorption of lead ions from aqueous solution on the surface of the mineral goethite (α-FeOOH) as a function of pH and adsorbate concentration in 0.1 M NaNO 3 solution. Results obtained from the dried surface by X-ray photoelectron spectroscopy (XPS) are in good agreement with data from spectrophotometric analysis of lead ions remaining in the supernatant liquid. Lead adsorption as a function of pH shows an adsorption edge near pH 6 and maximizes by pH 7.5. The surface atomic Pb/Fe ratio at saturation as measured by XPS is 0.93 leading to an apparent high adsorption site density of 14.2 sites/nm 2. A characteristic low binding energy (BE) XPS feature is present in the Pb 4f XPS signal in the pH range 6-8. Comparison with literature predictions of the speciation of lead at a goethite surface suggests that this XPS feature is perhaps associated with a FeOPb + complex. At high Pb(II) concentrations some polynuclear complexes probably form. They may be responsible for the high site density value which, while crystallographically possible, is much higher than values reported by others working at lower Pb concentrations.

  9. Characterization of Cr/SiO 2 catalysts and ethylene polymerization by XPS

    Science.gov (United States)

    Gaspar, A. B.; Perez, C. A. C.; Dieguez, L. C.

    2005-11-01

    Cr/SiO 2 catalysts with 1 or 3 wt.% Cr loadings and different chromium precursors were characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). A method to determine chromium species in the sample was developed through the decomposition of the Cr 2p XPS spectrum in Cr 6+ and Cr 3+ standard spectra. The results of the binding energy from the Cr 2p region and of the distribution of chromium species allowed to evaluate the dynamic photo-reduction of the surface chromium species during XPS analysis. Photo-reduction of surface Cr 6+ to Cr 3+ species was verified for all samples supported in silica, depending on the precursor and chromium content. Bulk CrO 3 and Cr 2O 3 standards did not reveal variation in the binding energy of Cr 2p 3/2, but a physical mixture of CrO 3 with SiO 2 presented photo-reduction. The behavior of this mixture resembled to the catalysts and suggests the participation of the surface hydroxyls of silica in the photo-reduction process. XPS intensity measurements for assessing dispersion of chromium oxide were used to compare the calcined and reduced catalysts to different chromium precursors. Polyethylene chains were detected by in situ XPS, while oligomerization products were not observed.

  10. Characterization of Cr/SiO2 catalysts and ethylene polymerization by XPS

    International Nuclear Information System (INIS)

    Gaspar, A.B.; Perez, C.A.C.; Dieguez, L.C.

    2005-01-01

    Cr/SiO 2 catalysts with 1 or 3 wt.% Cr loadings and different chromium precursors were characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). A method to determine chromium species in the sample was developed through the decomposition of the Cr 2p XPS spectrum in Cr 6+ and Cr 3+ standard spectra. The results of the binding energy from the Cr 2p region and of the distribution of chromium species allowed to evaluate the dynamic photo-reduction of the surface chromium species during XPS analysis. Photo-reduction of surface Cr 6+ to Cr 3+ species was verified for all samples supported in silica, depending on the precursor and chromium content. Bulk CrO 3 and Cr 2 O 3 standards did not reveal variation in the binding energy of Cr 2p 3/2 , but a physical mixture of CrO 3 with SiO 2 presented photo-reduction. The behavior of this mixture resembled to the catalysts and suggests the participation of the surface hydroxyls of silica in the photo-reduction process. XPS intensity measurements for assessing dispersion of chromium oxide were used to compare the calcined and reduced catalysts to different chromium precursors. Polyethylene chains were detected by in situ XPS, while oligomerization products were not observed

  11. XPS characterization of silver exchanged ETS-10 and mordenite molecular sieves.

    Science.gov (United States)

    Anson, A; Maham, Y; Lin, C C H; Kuznicki, T M; Kuznicki, S M

    2009-05-01

    Silver exchanged molecular sieves ETS-10 (Ag-ETS-10) and mordenite (Ag-mordenite) were dehydrated under vacuum at temperatures between 100 degrees C-350 degrees C. Changes in the state of the silver were studied using X-ray photoelectron spectroscopy (XPS). Silver cations in titanosilicate Ag-ETS-10 are fully reduced to Ag(0) at temperatures as low as 150 degrees C. The characteristic features of the XPS spectrum of silver in this Ag-ETS-10 species correspond to only metallic silver. The signal for metallic silver is not observed in the XPS spectrum of aluminosilicate Ag-mordenite, indicating that silver cations are not reduced, even after heating to 350 degrees C.

  12. XPS and NEXAFS analysis of dimethyl sulfide adsorbed on the Rh(PVP) nanoparticle surface

    International Nuclear Information System (INIS)

    Niwa, Hironori; Ogawa, Satoshi; Yagi, Shinya; Kutluk, Galif

    2010-01-01

    We have studied the adsorption reaction of dimethyl sulfide (DMS: (CH 3 ) 2 S) on the surface of Rh(PVP) nanoparticles by using AFM, XPS and NEXAFS techniques. The AFM images show the degree of dispersion of the Rh(PVP) nanoparticles depends on the amount of them. The in-situ XPS results indicate that the dissociation reaction of DMS into atomic S does not depend upon the existence of the Rh(PVP) nanoparticles. The NEXAFS results show that there is a strong chemical bonding between Rh(PVP) nanoparticle and atomic S. The ex-situ XPS results show the atomic S adsorbed on the Rh(PVP) nanoparticles partially desorb by exposing to the air. (author)

  13. Selected Area XPS Analysis for Identification of Pigment Compounds in Microscopic Paint Flakes

    Directory of Open Access Journals (Sweden)

    Bryony Joanne James

    2008-01-01

    Full Text Available The application of X-ray photoelectron spectroscopy to the analysis of paint flakes from a painting by Henry Fuseli (1741–1825 is presented. Historically, the application of XPS to art conservation and restoration studies has been limited by the poor spatial resolution of the technique. Presented here is the successful analysis of paint flakes in the order of 100 μm using “imaging” XPS in conjunction with selected area analysis. Raman microscopy failed to satisfactorily identify the compounds present in this instance, and energy dispersive spectroscopy could not differentiate between lead and sulphur (two of the elements of interest due to the limited energy resolution inherent in that technique. Using XPS analysis of the lead 4f peak revealed that the pigment was a lead-based pigment, in this case comprising exclusively lead-sulphur compounds.

  14. Surface Characterization of Polymer Blends by XPS and ToF-SIMS

    Directory of Open Access Journals (Sweden)

    Chi Ming Chan

    2016-08-01

    Full Text Available The surface properties of polymer blends are important for many industrial applications. The physical and chemical properties at the surface of polymer blends can be drastically different from those in the bulk due to the surface segregation of the low surface energy component. X-ray photoelectron spectroscopy (XPS and time-of-flight secondary mass spectrometry (ToF-SIMS have been widely used to characterize surface and bulk properties. This review provides a brief introduction to the principles of XPS and ToF-SIMS and their application to the study of the surface physical and chemical properties of polymer blends.

  15. XPS and SEM studies of chromium oxide films chemically formed on stainless steel 316 L

    International Nuclear Information System (INIS)

    Stefanov, P.; Marinova, T.

    2000-01-01

    The structure and composition of chromium oxide films formed on stainless steel by immersion in a chromium electrolyte have been studied by SEM and XPS. Cr 2 O 3 crystallites in the range 30-150 nm are fully developed and cover the whole surface. The chemical composition in the depth and the thickness of the oxide layer have been determined by XPS sputter profiles. The oxide film can be described within the framework of a double layer consisting of a thin outer hydrated layer and an inner layer of Cr 2 O 3 . (orig.)

  16. Quantitative analysis of satellite structures in XPS spectra of gold and silver

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, N., E-mail: nipauly@ulb.ac.be [Université libre de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), 50 av. F. D. Roosevelt, B-1050 Brussels (Belgium); Yubero, F. [Instituto de Ciencia de Materiales de Sevilla, Univ. Sevilla – CSIC, av. Américo Vespucio 49, E-41092 Sevilla (Spain); Tougaard, S. [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark)

    2016-10-15

    Highlights: • Accurate determination of the energy loss functions for Au and Ag. • Calculation of effective inelastic electron scattering cross sections for Au and Ag. • Convolution of these cross sections with varying model primary spectra F(E). • Variation of F(E) until a good agreement with experimental XPS spectra is reached. • Quantitative determination of Au 4f and Ag 3d characteristics. - Abstract: Identification of specific chemical states and local electronic environments at surfaces by X-ray photoelectron spectroscopy (XPS) is often difficult because it is not straightforward to quantitatively interpret the shape and intensity of shake-up structures that originate from the photoexcitation process. Indeed the shape and intensity of measured XPS structures are strongly affected by both extrinsic excitations due to electron transport out of the surface and intrinsic excitations induced by the sudden creation of the static core hole. These processes must be taken into account to quantitatively extract, from experimental XPS, the primary excitation spectrum of the considered transition which includes all effects that are part of the initial photo-excitation process, i.e. lifetime broadening, spin–orbit coupling, and multiplet splitting. It was previously shown [N. Pauly, S. Tougaard, F. Yubero, Surf. Sci. 620 (2014) 17] that both extrinsic and intrinsic excitations could be included in an effective energy-differential inelastic electron scattering cross section for XPS which is then convoluted with the primary excitation spectrum to model the full XPS spectrum. This method can thus be applied to determine the primary excitation spectrum from any XPS spectrum. We use this approach in the present paper to determine the Au 4f and Ag 3d photoemission spectra from pure metals. We observe that characteristic energy loss features of the XPS spectra are not only due to photoelectron energy losses. We thus prove the existence of a double shake-up process

  17. Thorough XPS analyses on overlithiated manganese spinel cycled around the 3V plateau

    Energy Technology Data Exchange (ETDEWEB)

    Grissa, R. [IPREM ECP − UMR CNRS 5254, Université de Pau et des Pays de l’Adour, Hélioparc Pau-Pyrénées, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Martinez, H., E-mail: herve.martinez@univ-pau.fr [IPREM ECP − UMR CNRS 5254, Université de Pau et des Pays de l’Adour, Hélioparc Pau-Pyrénées, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Cotte, S.; Galipaud, J.; Pecquenard, B. [CNRS, Université de Bordeaux, ICMCB–UPR 9048 and Bordeaux INP, 87 Avenue du Dr. Schweitzer, F-33600 Pessac (France); Cras, F.Le [CEA LETI, 17 rue des Martyrs, F-38054 Grenoble (France); Université Grenoble Alpes, F-38000 Grenoble (France)

    2017-07-31

    Highlights: • Mn2p XPS spectra of Li{sub 1+x}Mn{sub 2-x}O{sub 4} (0 < x < 0.25) fitted with reference samples. • XPS Mn mean oxidation states agrees with XRD structural study. • Li{sub 1.2}Mn{sub 1.8}O{sub 4} thin films cycled versus lithium arounds 3 V in liquid electrolyte. • Electrochemical results (over 20 cycles) related to Mn oxidation states evolution. • Irreversible capacity explained on the basis of XPS by active material delamination. - Abstract: Lithium-rich spinel Li{sub 1.2}Mn{sub 1.8}O{sub 4} thin film electrodes operated at 3 V/Li{sup +}/Li are studied by means of X-ray photoelectron spectroscopy (XPS), mainly on the basis of the evolution of the Mn2p XPS peak during the electrode cycling. The analysis of this core peak has long been debated in literature given its complex character. Based on manganese oxide references, MnO (Mn{sup 2+}), Mn{sub 2}O{sub 3}(Mn{sup 3+}) and Li{sub 2}MnO{sub 3}(Mn{sup 4+}), we propose a deconvolution method to identify each Mn oxidation state. This method is then used for the deconvolution of Mn2p XPS peaks of bulk lithium-rich spinels Li{sub 1+x}Mn{sub 2-x}O{sub 4} (0 ≤ x ≤ 0.25) for validation before proceeding to the study of cycled Li{sub 1.2}Mn{sub 1.8}O{sub 4} thin film electrodes. Electrochemical measurements exhibit significant capacity loss during the first cycle. Based on XPS analyses, this phenomenon could be explained by mechanical breakup of parts of the electrode. A stable behavior during subsequent cycles is then observed. The presence of Mn{sup 2+} species (XPS) at the most top surface of the electrode and the significant polarization observed during the discharge illustrate the kinetical limitation of the two-phase reaction, despite the reduced thickness of the electrode material.

  18. A comparative study on defect estimation using XPS and Raman spectroscopy in few layer nanographitic structures.

    Science.gov (United States)

    Ganesan, K; Ghosh, Subrata; Gopala Krishna, Nanda; Ilango, S; Kamruddin, M; Tyagi, A K

    2016-08-10

    Defects in planar and vertically oriented nanographitic structures (NGSs) synthesized by plasma enhanced chemical vapor deposition (PECVD) have been investigated using Raman and X-ray photoelectron spectroscopy. While Raman spectra reveal the dominance of vacancy and boundary type defects respectively in vertical and planar NGSs, XPS provides additional information on vacancy related defect peaks in the C 1s spectrum, which originate from non-conjugated carbon atoms in the hexagonal lattice. Although an excellent correlation prevails between these two techniques, our results show that estimation of surface defects by XPS is more accurate than Raman analysis. Nuances of these techniques are discussed in the context of assessing defects in nanographitic structures.

  19. Research on the surface chemical behavior of uranium metal in hydrogen atmosphere by XPS

    International Nuclear Information System (INIS)

    Fu Xiaoguo; Wang Xiaolin; Yu Yong; Zhao Zhengping

    2001-01-01

    The surface chemical behavior clean uranium metal in hydrogen atmosphere at 100 and 200 degree C is studied by X-ray photoelectron spectroscopy (XPS), respectively. It leads to hydriding reaction when the hydrogen exposure is 12.0 Pa·s, and the U4f 7/2 binding energy of UH 3 is found to be 378.7 eV. The higher temperature (200 degree C) is beneficial to UH 3 formation at the same hydrogen exposures. XPS elemental depth profiles indicate that the distribution of uranium surface layer is UO 2 , UH 3 and U after exposure to 174.2 Pa·s hydrogen

  20. XPS and XAES of polyethylenes aided by line shape analysis: The effct of electron irradiation

    Czech Academy of Sciences Publication Activity Database

    Lesiak, B.; Zemek, Josef; Houdková, Jana; Jiříček, Petr; Jozwik, A.

    2009-01-01

    Roč. 94, č. 10 (2009), s. 1714-1721 ISSN 0141-3910 R&D Projects: GA AV ČR IAA100100622 Institutional research plan: CEZ:AV0Z10100521 Keywords : XPS * XAES * line shape analysis * electron beam degradation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.154, year: 2009

  1. Quantitative depth profiling of K-doped fullerene films using XPS and SIMS

    Czech Academy of Sciences Publication Activity Database

    Oswald, S.; Janda, Pavel; Dunsch, L.

    2003-01-01

    Roč. 141, 1-2 (2003), s. 79-85 E-ISSN 1436-5073 Institutional research plan: CEZ:AV0Z4040901 Keywords : XPS * SIMS * depth profiling * fullerenes * doping Subject RIV: CG - Electrochemistry Impact factor: 0.784, year: 2003

  2. On the oxide formation on stainless steels AISI 304 and incoloy 800H investigated with XPS

    NARCIS (Netherlands)

    Langevoort, J.C.; Sutherland, I.; Hanekamp, L.J.; Gellings, P.J.

    1987-01-01

    The influence of cold work on the initially formed oxide layer on the stainless steels AISI 304 and Incology 800H has been studied by XPS. Oxidations were performed at pressures of 10-6-10-4 Pa and temperatures of 300–800 K. All samples showed a similar oxidation behaviour. The oxidation rates of

  3. XPS and factor analysis study of initial stages of cerium oxide growth on polycrystalline tungsten

    Czech Academy of Sciences Publication Activity Database

    Polyak, Yaroslav; Bastl, Zdeněk

    2015-01-01

    Roč. 47, č. 6 (2015), s. 663-671 ISSN 0142-2421 Institutional support: RVO:68378271 ; RVO:61388955 Keywords : XPS * FA * PLD * cerium oxide * WO 3 * Ce (3d) Subject RIV: CF - Physical ; Theoretical Chemistry; CF - Physical ; Theoretical Chemistry (UFCH-W) Impact factor: 1.018, year: 2015

  4. Electronic excitation in XPS spectra of argon and potassium implanted in aluminium

    International Nuclear Information System (INIS)

    Abbate, M.

    1988-01-01

    XPS (X-ray photoemission spectroscopy) spectra were obtained for argon and potassium implanted in aluminium to study the plasmons excitation which are produced during photoemission. It was found that in these systems it was produced more intrinsic plasmons than extrinsic. (A.C.A.S.) [pt

  5. Diamond/carbon nanotube composites: Raman, FTIR and XPS spectroscopic studies

    Czech Academy of Sciences Publication Activity Database

    Varga, Marián; Ižák, Tibor; Vretenár, V.; Kozak, Halyna; Holovský, Jakub; Artemenko, Anna; Hulman, M.; Skákalová, V.; Lee, D. S.; Kromka, Alexander

    2016-01-01

    Roč. 111, Jan (2016), s. 54-61 ISSN 0008-6223 R&D Projects: GA ČR GC15-22102J; GA MŠk(CZ) 7AMB14SK037 Institutional support: RVO:68378271 Keywords : diamond * carbon nanotubes * spectroscopy * Raman * FTIR * XPS Subject RIV: JI - Composite Materials Impact factor: 6.337, year: 2016

  6. An In-situ XPS study of non-evaporable ZrVFe getter material

    Directory of Open Access Journals (Sweden)

    Jang-Hee Yoon

    2010-03-01

    Full Text Available To investigate the temperature dependence of a synthesized Zr57V36Fe7 non evaporable vacuum getter material, the in-situ temperature x-ray photoelectron spectroscopy (in-situ XPS were performed in a UHV chamber equipped with a programmable ceramic sample heating system. The surface and bulk composition of Zr, V, and Ti was determined in the as-received state and after in-situ heating from 50℃ to 600℃ at 50℃per step. The peak fitting results for O 1s, C 1s, Zr 3d, V 2p, and Fe 2p high resolution spectra were acquired and the chemical state of the elements were then characterized as a function of heating temperature. In-situ XPS investigations showed that oxide reduction proceeds via the formation of sub-oxides with the simultaneous formation of carbides in the region near the surface. The activation temperature for completion of the Zr57V36Fe7 alloy, which approximates the XPS peaks changed from oxide to metallic state(20 % of the oxide peak, was determined around 480℃. The findings suggest that the in-situ temperature XPS technique is a useful analytical tool for evaluating activation characteristics of NEG materials.

  7. XPS and surface resistivity measurements of plasma - treated FEP co-polymer

    International Nuclear Information System (INIS)

    Pitrus, R.K.; Brack, N.; Liesegang, J.; Pigram, P.J.

    2002-01-01

    Full text: Fluorinated polymers such as fluorinated ethylene propylene (FEP) and poly(tetrafluoroethylene) (PTFE) play an important role in many applications due to their many desirable properties such as chemical resistivity, inertness, electrical stability and low dielectric constant; however, one disadvantage of fluorinated polymers is their extreme surface hydrophobicity. Previous studies show that plasma treatment will modify the surface by increasing the surface free energy and also offer a rapid and convenient method for pre-treating the polymers for many purposes. This paper, through resistivity and XPS (x-ray photoelectron spectroscopy) measurements, attempts to discover basic effects of such plasma treatment. Fluorinated ethylene propylene (FEP) co-polymer film of (0.05) mm thickness (obtained commercially) and with the following structure (CF 2 -CF 2 )-(CF(CF 3 )CF 2 )- was used. A suitable cleaning procedure was used to remove adventitious carbon from the surface. XPS has been used to study FEP film properties. The spectra of XPS were analyzed with the main focus on carbon and fluorine as they compose the elemental component of FEP film. A value of 2.05 was obtained for the F/C ratio, which is slightly higher than the theoretical F/C value estimated from the chemical structure of FEP (F/C 2). The clean film was then air plasma treated (pressure 10 -1 torr and power 30W) for various treatment times to produce a higher energy fluoropolymer surface. XPS studies investigated changes to the polymer surface and determined that oxidation occurs on the FEP surface. The oxidation reactions on the FEP surface form oxygen functional groups such as C-O and C=O groups. The results also show that the percentage of CF 2 and CF 3 in the co-polymer surface decreased with exposure time and the percentage of CF, C-C, C-O and C=O increased. There is a sharp decrease in F/C ratio and increase in O/C ratio. In addition to XPS, the resistivity of FEP-film was measured by a

  8. Concepções sobre drogas por adolescentes escolares

    OpenAIRE

    Faria Filho, Edson Arantes; Queiros, Pollyanna Siqueira; Medeiros, Marcelo; Rosso, Claci Fatima Weirich; Souza, Márcia Maria de

    2015-01-01

    RESUMOObjetivo:analisar concepções de adolescentes escolares da educação básica sobre drogas em geral.Método:abordagem qualitativa de grupos focais com 16 adolescentes estudantes. Os dados coletados foram analisados por Análise de Conteúdo, onde emergiram as seguintes categorias “Significado de drogas”; “Convivendo com o uso de drogas”; “Opiniões, crenças e atitudes em relação ao uso de drogas” e “Prevenindo o uso indevido de drogas na adolescência”.Resultados:os adolescentes conhecem algumas...

  9. Detergency of stainless steel surface soiled with human brain homogenate: an XPS study

    Energy Technology Data Exchange (ETDEWEB)

    Richard, M. [Ecole Centrale de Lyon, UMR 5513 LTDS, 69 134 Ecully (France) and Laboratoires ANIOS, 59 260 Lille-Hellemmes (France)]. E-mail: marlene.richard@ec-lyon.fr; Le Mogne, Th. [Ecole Centrale de Lyon, UMR 5513 LTDS, 69 134 Ecully (France); Perret-Liaudet, A. [Hopital Neurologique de Lyon et INSERM U512, 69 394 Lyon (France); Rauwel, G. [Laboratoires ANIOS, 59 260 Lille-Hellemmes (France); Criquelion, J. [Laboratoires ANIOS, 59 260 Lille-Hellemmes (France); De Barros, M.I. [Ecole Centrale de Lyon, UMR 5513 LTDS, 69 134 Ecully (France); Cetre, J.C. [Unite d' Hygiene et d' Epidemiologie, Hopital de la Croix Rousse, 69 317 Lyon (France); Martin, J.M. [Ecole Centrale de Lyon, UMR 5513 LTDS, 69 134 Ecully (France)

    2005-02-15

    In the detergency field of re-usable medical devices, a special attention is focused on the non conventional transmissible agent called prions which is a proteinaceous infectious agent. Few cleaning procedures are effective against prions and few techniques are available to study cleaning effectiveness with respect to proteins in general. In our study, X-ray photoelectron spectroscopy (XPS) has been used to evaluate the effectiveness of detergent formulations to remove proteins from stainless steel surface soiled with a brain homogenate (BH) from human origin. Our results showed that XPS is a reliable surface analysis technique to study chemical species remaining on surface and substrate properties after cleaning procedures. A semi-quantitative evaluation of the detergency effectiveness could also be performed.

  10. XPS and FTIR investigation of the surface properties of different prepared titania nano-powders

    DEFF Research Database (Denmark)

    Jensen, Henrik; Solovyev, Alexey; Lie, Zheshen

    2005-01-01

    Surface studies of nano-sized TiO2 powders prepared by different methods showed that the preparation method had great impact on the surface properties. XPS measurements showed that the oxygen composition was related to the preparation method. The chloride method yielded the lowest amount of surface...... oxygen (29%) and sol–gel prepared powder showed the greatest amount of surface oxygen (66%) in the form of surface hydroxyl groups. The remaining oxygen was identified as lattice oxygen. The powder prepared by the sol–gel method contained carbon impurities originating from residual alkoxy groups....... Supercritical sol–gel prepared powder and powder prepared by the sulphate method revealed same trends regarding oxygen composition with 44–47% being surface oxygen; neither contained carbon impurities. The results obtained from XPS were confirmed by FTIR measurements....

  11. Applications of high lateral and energy resolution imaging XPS with a double hemispherical analyser based spectromicroscope

    International Nuclear Information System (INIS)

    Escher, M.; Winkler, K.; Renault, O.; Barrett, N.

    2010-01-01

    The design and applications of an instrument for imaging X-ray photoelectron spectroscopy (XPS) are reviewed. The instrument is based on a photoelectron microscope and a double hemispherical analyser whose symmetric configuration avoids the spherical aberration (α 2 -term) inherent for standard analysers. The analyser allows high transmission imaging without sacrificing the lateral and energy resolution of the instrument. The importance of high transmission, especially for highest resolution imaging XPS with monochromated laboratory X-ray sources, is outlined and the close interrelation of energy resolution, lateral resolution and analyser transmission is illustrated. Chemical imaging applications using a monochromatic laboratory Al Kα-source are shown, with a lateral resolution of 610 nm. Examples of measurements made using synchrotron and laboratory ultra-violet light show the broad field of applications from imaging of core level electrons with chemical shift identification, high resolution threshold photoelectron emission microscopy (PEEM), work function imaging and band structure imaging.

  12. Chemical state analysis of conversion coatings by SR-XPS and TEY-XANES

    CERN Document Server

    Noro, H; Nagoshi, M

    2002-01-01

    Chromate coatings on galvanized steel have been studied by Synchrotron Radiation (SR) based techniques that include X-ray Photoelectron Spectroscopy (XPS) and Total-Electron-Yield X-ray Absorption Near Edge Structure (TEY-XANES). Non-destructive depth profiling of the coatings by SR-XPS reveals the enhancement of Cr sup 6 sup + in the outer surface. TEY-XANES spectroscopy based on simple specimen current measurement is demonstrated as an effective technique for analyzing chemical states of conversion coatings on general bulk substrates. The sampling depth of this technique, which exceeds several tens of nanometer, is determined by the penetration length of Auger electrons excited by X-ray and the inelastic mean free path of secondary electrons excited by inelastically scattered Auger electrons. The chemical states of phosphoric acid added chromate coatings are studied using this technique. The phosphoric acid is taken into the chromate coatings as partially changed into zinc and chromium phosphates, and the r...

  13. SEM and XPS study of layer-by-layer deposited polypyrrole thin films

    Science.gov (United States)

    Pigois-Landureau, E.; Nicolau, Y. F.; Delamar, M.

    1996-01-01

    Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3-4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces.

  14. SEM and XPS study of layer-by-layer deposited polypyrrole thin films

    International Nuclear Information System (INIS)

    Pigois-Landureau, E.; Nicolau, Y.F.; Delamar, M.

    1996-01-01

    Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3 endash 4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces. copyright 1996 American Institute of Physics

  15. Characterization on Contacting Surfaces of MEMS Electrostatic Switches by SEM, EDXA, and XPS

    Directory of Open Access Journals (Sweden)

    I. A. Afinogenov

    2015-01-01

    Full Text Available We focus on the origin and sources of surface contamination and defects causing the failure of MEMS electrostatic switches. The morphology, and elemental and chemical compositions of the contacting surfaces, conducting paths, and other parts of switches have been characterized by means of SEM, EDXA, and XPS in order to understand the difference between the data collected for the devices that had passed the electrical conductivity test and those found to be defective. C, O, Al, Ca, Ti, Cu, and some other impurities were detected on the details of defective switches. Contrariwise, the working switches were found to be clean, at least on the level of EDXA and XPS sensitivity. The main sources of surface contamination and defects were incompletely deleted sacrificial layers, substrate materials, and electrolytes employed for Rh plating of the contacts. The negative influence of foreign microparticles, especially alumina and copper oxides, on the conductivity and porosity of contacts was highlighted.

  16. Structural evolution of Ga-Ge-Te glasses by combined EXAFS and XPS analysis

    Energy Technology Data Exchange (ETDEWEB)

    Golovchak, R. [Department of Physics and Astronomy, Austin Peay State University, Clarksville, Tennessee 37044 (United States); Materials Science and Engineering Department, Lehigh University, 5 East Packer Avenue, Bethlehem, Pennsylvania 18015 (United States); Calvez, L.; Bureau, B. [Laboratoire des Verres et Ceramiques, Institut des Sciences Chimiques de Rennes, UMR-CNRS6226, University of Rennes 1 (France); Jain, H. [Materials Science and Engineering Department, Lehigh University, 5 East Packer Avenue, Bethlehem, Pennsylvania 18015 (United States)

    2013-08-07

    The structural evolution of Ga{sub x}Ge{sub y}Te{sub 100−x−y} glasses in the vicinity of GeTe{sub 4}-GaTe{sub 3} pseudo-binary tie-line is determined with high-resolution X-ray photoelectron (XPS) and extended X-ray absorption fine structure (EXAFS) spectroscopies. The analysis of XPS data is complicated by similar electronegativity values for the constituent chemical elements, but then the interpretation is facilitated by information from complementary EXAFS analysis of the structure around each element independently. The results show 4/4/2 coordination for Ga/Ge/Te atoms and absence of Ga(Ge)-Ge(Ga) bonds or extended Te clusters in significant concentrations within the whole range of studied composition. The observed structural features correlate well with the measured basic physical properties of Ga-containing germanium telluride glasses.

  17. Pd adsorption on Si(1 1 3) surface: STM and XPS study

    International Nuclear Information System (INIS)

    Hara, Shinsuke; Yoshimura, Masamichi; Ueda, Kazuyuki

    2008-01-01

    Pd-induced surface structures on Si(1 1 3) have been studied by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). In the initial process of the Pd adsorption below 0.10 ML, Pd silicide (Pd 2 Si) clusters are observed to form randomly on the surface. By increasing the Pd coverage to 0.10 ML, the clusters cover the entire surface, and an amorphous layer is formed. After annealing the Si(1 1 3)-Pd surface at 600 deg. C, various types of islands and chain protrusions appears. The agglomeration, coalescence and crystallization of these islands are observed by using high temperature (HT-) STM. It is also found by XPS that the islands correspond to Pd 2 Si structure. On the basis of these results, evolution of Pd-induced structures at high temperatures is in detail discussed

  18. XPS characterization of the anodic oxide film formed on uranium metal in sodium hydroxide solution

    International Nuclear Information System (INIS)

    Fu Xiaoguo; Wang Xiaolin; Guo Huanjun; Wang Qingfu; Zhao Zhengping; Zhong Yongqiang

    2002-01-01

    X-ray photoelectron spectroscopy (XPS) is used to examine the anodic oxide film formed on uranium metal in 0.8 mol/L NaOH solution. The U4f 7/2 fitting spectra suggests that the anodic oxide film is composed of uranium trioxide and a small amount of UO 2+x . Under UHV condition, the U4f peak shifts to the lower binding energy, while a gradual increase in the intensity of U5f peak and the broad of U4f peak are also observed. All of these changes are due to reduction of uranium trioxide in the anodic oxide film. XPS quantitative analysis confirms the occurrence of reduction reaction

  19. Study of the local structure of binary surfaces by electron diffraction (XPS, LEED)

    OpenAIRE

    Gereová, Katarína

    2006-01-01

    Study of local structure of binary surface with usage of ultra-thin film of cerium deposited on a Pd (111) single-crystal surface is presented. X-ray photoelectron spectroscopy and diffraction (XPS, XPD), angle resolved UV photoemission spectroscopy (ARUPS) and low energy electron diffraction (LEED) was used for our investigations. LEED and X-ray excited photoemission intensities results represent a surface-geometrical structure. As well, mapping of ultra-violet photoelectron intensities as a...

  20. XPS investigations on the UV-laser ablation mechanism of poly(ether imide)

    Energy Technology Data Exchange (ETDEWEB)

    Wambach, J.; Kunz, T.; Schnyder, B.; Koetz, R.; Wokaun, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    UV-Laser ablated samples of poly(ether imide) [Kapton{sup TM}] were studied with small-spot XPS. Applying fluences above the threshold level (0.167 J/cm{sup 2}) resulted in the expected behaviour of a decline of both nitrogen and oxygen. Below the threshold level a hint for an altered ablation mechanism was found. (author) 1 fig., 5 refs.

  1. XPS Analysis of AuGeNi/Cleaved GaAs(110 Interface

    Directory of Open Access Journals (Sweden)

    Constantin-Catalin Negrila

    2016-01-01

    Full Text Available The depth composition of the thin layer alloy, AuGeNi, devoted to acting as an ohmic contact on n-GaAs(110 has been investigated by in situ XPS combined with Argon ion sputtering techniques. The fresh cleaved surfaces, supposed to be free of oxygen, were usually deposited with a 200 nm metallic layer in high vacuum conditions (better than 10−7 torr, by thermal evaporation, and annealed at a 430–450° Celsius temperature for 5 minutes. About 18 sessions of ion Ar surfaces etching and intermediate XPS measurements were performed in order to reveal the border of the metal/semiconductor interface. The atomic concentrations of the chemical elements have been approximated. Au4f, Ga3d, Ga2p, As3d, As2p, Ni2p3/2, Ge3d, O1s, and C1s spectral lines were recorded. The Au, Ge, and Ni have a homogenous distribution while Ga and As tend to diffuse to the surface. Oxygen is present in the first layers of the surface while carbon completely disappears after the second etching step. The existence of an Au-Ga alloy was detected and XPS spectra show only metal Ni and Ge within the layer and at the interface. We tried to perform a study about the depth chemical composition profile analysis of AuGeNi layer on cleaved n-GaAs(110 by X-Ray Photoelectron Spectroscopy (XPS technique.

  2. Investigation of CoPd alloys by XPS and EPES using the pattern recognition method

    Czech Academy of Sciences Publication Activity Database

    Lesiak, B.; Zemek, Josef; Jiříček, Petr; Jozwik, A.

    2007-01-01

    Roč. 428, - (2007), s. 190-196 ISSN 0925-8388 R&D Projects: GA ČR GA202/06/0459 Institutional research plan: CEZ:AV0Z10100521 Keywords : CoPd alloys * x-ray photoelectron spectroscopy (XPS) * elastic peak electron spectroscopy (EPES) * pattern recognition method * fuzzy k-nearest neighbour rule (fkNN) * quantitative analysis * surface segregation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.455, year: 2007

  3. Comparison of optical models and signals from XPS and VASE characterized titanium after PBS immersion

    Czech Academy of Sciences Publication Activity Database

    Penttinen, N.; Hasoň, Stanislav; Silvennoinen, M.; Joska, L.; Silvennoinen, R.

    2012-01-01

    Roč. 285, č. 6 (2012), s. 965-968 ISSN 0030-4018 Grant - others:GA ČR(CZ) GAP108/10/1782 Program:GA Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : permittivity * XPS titanium * diffractive optical element-based sensor Subject RIV: BO - Biophysics Impact factor: 1.438, year: 2012

  4. Lead-silicate glass surface sputtered by an argon cluster ion beam investigated by XPS

    Czech Academy of Sciences Publication Activity Database

    Zemek, Josef; Jiříček, Petr; Houdková, Jana; Jurek, Karel; Gedeon, O.

    2017-01-01

    Roč. 469, Aug (2017), s. 1-6 ISSN 0022-3093 R&D Projects: GA MŠk LM2015088; GA ČR(CZ) GA15-12580S Institutional support: RVO:68378271 Keywords : lead-silicate glass * XPS * BO * NBO * Argon duster ion beam sputtering * X-ray irradiation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.124, year: 2016

  5. An XPS study of tarnishing of a gold mask from a pre-Columbian culture

    International Nuclear Information System (INIS)

    Bastidas, D.M.; Cano, E.; Gonzalez, A.G.; Fajardo, S.; Lleras-Perez, R.; Campo-Montero, E.; Belzunce-Varela, F.J.; Bastidas, J.M.

    2008-01-01

    The tarnishing originated on a hammered gold mask was analysed. Red tarnishing was observed after three years of storage in an indoor environment in the Gold Museum of Banco de la Republica, Bogota, Colombia. Silver sulphide (Ag 2 S) and silver sulphate (Ag 2 SO 4 ) compounds were identified as the origin of the tarnishing phenomenon, which is attributed to environmental contamination. Atomic absorption spectroscopy (AAS) and X-ray photoelectron spectroscopy (XPS) techniques were used

  6. Surface chemical characterization of PM{sub 10} samples by XPS

    Energy Technology Data Exchange (ETDEWEB)

    Atzei, Davide, E-mail: datzei@unica.it [Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, S.S. 554 Bivio per Sestu, I-09042 Monserrato, Cagliari (Italy); Fantauzzi, Marzia; Rossi, Antonella [Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, S.S. 554 Bivio per Sestu, I-09042 Monserrato, Cagliari (Italy); Fermo, Paola [Dipartimento di Chimica, Università degli Studi Milano, Via Golgi 19, I-20133 Milano (Italy); Piazzalunga, Andrea [Dipartimento di Chimica, Università degli Studi Milano, Via Golgi 19, I-20133 Milano (Italy); Dipartimento di Scienze dell’Ambiente e del territorio, Università degli Studi di Milano-Bicocca, Piazza della Scienza 1, I-20122 Milano (Italy); Valli, Gianluigi; Vecchi, Roberta [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, I-20133 Milano (Italy)

    2014-07-01

    Samples of particulate matter (PM) collected in the city of Milan during wintertime were analyzed by X-ray photoelectron spectroscopy (XPS), thermal optical transmittance (TOT), ionic chromatography (IC) and X-ray fluorescence (XRF) in order to compare quantitative bulk analysis and surface analysis. In particular, the analysis of surface carbon is here presented following a new approach for the C1s curve fitting aiming this work to prove the capability of XPS to discriminate among elemental carbon (EC) and organic carbon (OC) and to quantify the carbon-based compounds that might be present in the PM. Since surface of urban PM is found to be rich in carbon it is important to be able to distinguish between the different species. XPS results indicate that aromatic and aliphatic species are adsorbed on the PM surface. Higher concentrations of (EC) are present in the bulk. Also nitrogen and sulfur were detected on the surfaces and a qualitative and quantitative analysis is provided. Surface concentration of sulfate ion is equal to that found by bulk analysis; moreover surface analysis shows an additional signal due to organic sulfur not detectable by the other methods. Surface appears to be also enriched in nitrogen.

  7. GD-OES and XPS coupling: A new way for the chemical profiling of photovoltaic absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Mercier, Dimitri, E-mail: dimitri.mercier@uvsq.fr [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Bouttemy, Muriel; Vigneron, Jackie [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Chapon, Patrick [HORIBA Jobin Yvon SAS, F-91165 Longjumeau (France); Etcheberry, Arnaud [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France)

    2015-08-30

    Highlights: • The coupling between GD-OES and XPS analysis is a promising way for fine characterization of thin layers. • Crater surface modifications obtained after GD-OES sputtering depend to the plasma gas. • Inversion of the gas flow improves the surface of the crater. • The modified layer is totally eliminated a few seconds after restarting GD-OES sputtering. - Abstract: In this paper, we examine the complementarity of Glow Discharge Optical Emission Spectroscopy (GD-OES) and X Ray Photoelectron Spectroscopy (XPS) for the realization of fine chemical depth profiling of photovoltaic absorbers using Cu(In,Ga)Se{sub 2} (CIGS) materials. The possibility to use sequentially these two techniques is discussed in this paper. We have evaluated the chemical modifications of the crater after GD-OES analyses which depend on the manner of finishing the plasma etching sequence; and we propose different ways to limit or eliminate this effect. For the moment, an intermediate step (wet chemical etching or weak sputtering) is required to obtain a CIGS phase in the crater. Finally, we have demonstrated the possibility to restart the GD-OES analyses of the materials after XPS quantification or GD-OES breaking without modifying the profile shape.

  8. XPS and NEXAFS study of tyrosine-terminated propanethiol assembled on gold

    CERN Document Server

    Petoral, R M

    2003-01-01

    Tyrosine-terminated propanethiol (TPT), tyrosine linked to 3-mercaptopropionic acid through an amide bond, is adsorbed to gold surfaces. The adsorbates are characterized by means of X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS). XPS is used to investigate the chemical binding and electronic structure of the monolayer. Strong molecular binding of the tyrosine derivative on the gold surface through the sulfur atom is attained. Angle-dependent XPS results shows that TPT molecules are oriented with the sulfur atoms molecularly oriented close to the gold surface and that the phenol moiety is oriented away from the gold surface. Average orientation of the adsorbate on gold is deduced using the NEXAFS results. It shows that the main molecular axis is tilted approximately 38 deg. relative to the Au surface normal. The ring plane of the phenol moiety exhibits a preferential orientation with an average tilt angle of the normal of the ring plane from the surfa...

  9. Gold/silver core-shell 20 nm nanoparticles extracted from citrate solution examined by XPS

    Energy Technology Data Exchange (ETDEWEB)

    Engelhard, Mark H.; Smith, Jordan N.; Baer, Donald R.

    2016-06-01

    Silver nanoparticles of many types are widely used in consumer and medical products. The surface chemistry of particles and the coatings that form during synthesis or use in many types of media can significantly impact the behaviors of particles including dissolution, transformation and biological or environmental impact. Consequently it is useful to be able to extract information about the thickness of surface coatings and other attributes of nanoparticles produced in a variety of ways. It has been demonstrated that X-ray Photoelectron Spectroscopy (XPS) can be reliably used to determine the thickness of organic and other nanoparticles coatings and shells. However, care is required to produce reliable and consistent information. Here we report the XPS spectra from gold/silver core-shell nanoparticles of nominal size 20 nm removed from a citrate saturated solution after one and two washing cycles. The Simulation of Electron Spectra for Surface Analysis (SESSA) program had been used to model peak amplitudes to obtain information on citrate coatings that remain after washing and demonstrate the presence of the gold core. This data is provided so that others can compare use of SESSA or other modeling approaches to quantify the nature of coatings to those already published and to explore the impacts particle non-uniformities on XPS signals from core-shell nanoparticles.

  10. Quantitative Surface Analysis by Xps (X-Ray Photoelectron Spectroscopy: Application to Hydrotreating Catalysts

    Directory of Open Access Journals (Sweden)

    Beccat P.

    1999-07-01

    Full Text Available XPS is an ideal technique to provide the chemical composition of the extreme surface of solid materials, vastly applied to the study of catalysts. In this article, we will show that a quantitative approach, based upon fundamental expression of the XPS signal, has enabled us to obtain a consistent set of response factors for the elements of the periodic table. In-depth spadework has been necessary to know precisely the transmission function of the spectrometer used at IFP. The set of response factors obtained enables to perform, on a routine basis, a quantitative analysis with approximately 20% relative accuracy, which is quite acceptable for an analysis of such a nature. While using this quantitative approach, we have developed an analytical method specific to hydrotreating catalysts that allows obtaining the sulphiding degree of molybdenum quite reliably and reproducibly. The usage of this method is illustrated by two examples for which XPS spectroscopy has provided with information sufficiently accurate and quantitative to help understand the reactivity differences between certain MoS2/Al2O3 or NiMoS/Al2O3-type hydrotreating catalysts.

  11. Chemical characterization of selected high copper dental amalgams using XPS and XRD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Talik, E. [A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland)]. E-mail: talik@us.edu.pl; Babiarz-Zdyb, R. [A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Dziedzic, A. [Medical University of Silesia, Department of Conservative Dentistry and Periodontology, Akademicki 17 Sqr., 41-209 Bytom (Poland)

    2005-08-02

    The study was carried out to analyze some dependencies between the composition of seven high copper dental amalgams and mercury release behavior, as well as oxygen reactivity of metallic elements. Chemical comparative analysis of selected dental amalgams was carried out using X-ray photoelectron spectroscopy (XPS) technique and X-ray diffraction (XRD) method. The X-ray powder diffraction measurements revealed two main phases for measured amalgams: {gamma}{sub 1}-(Ag{sub 2}Hg{sub 3}) and {eta}'-(Cu{sub 6}Sn{sub 5}). The amount of mercury obtained by the XPS method was lower than the value quoted in the manufacturer's literature, which suggested evaporation of mercury under the UHV conditions. A linear decrease of oxygen and carbon contamination with the growing amount of Cu and Ag was observed. The XPS analysis showed that a high Sn concentration caused less resistance to oxidation. Some of the amalgams contained some extra elements, such as Bi, In, and Zn. All samples contained lead in metallic state and oxides. The amount of Ag, Cu, Sn ingredients determines the main properties of high copper amalgams and plays an important role in mercury evaporation. High tin concentration combined with the presence of smaller amounts of silver and copper (high Sn/Ag ratio) may influence the increase of mercury vaporization.

  12. Quantifying Small Changes in Uranium Oxidation States Using XPS of a Shallow Core Level

    Energy Technology Data Exchange (ETDEWEB)

    Ilton, Eugene S.; Du, Yingge; Stubbs, Joanne; Eng, Peter; Chaka, Anne M.; Bargar, John R.; Nelin, Constance J.; Bagus, Paul S.

    2017-12-29

    The U4f line is commonly used to determine uranium oxidation states with X-ray photoelectron spectroscopy (XPS). In contrast, the XPS of the shallow core-levels of uranium are rarely recorded. Nonetheless, theory has shown that the U 5d (and 5p) multiplet structure is very sensitive to oxidation state. In this contribution we extracted the U(IV) and U(V) 5d XPS peak shapes from near stoichiometric and relatively oxidized UO2 single crystal samples, respectively, where the oxidation state of U was constrained by fitting the 4f line. The empirically extracted 5d spectra were similar to the theoretically determined multiplet structures and were used, along with the relatively simple U(VI) component that was constrained by theory, to determine the oxidation states of UO2+x samples. The results showed a very strong correlation between oxidation states determined by the 5d and 4f line and suggested that the 5d might be more sensitive to minor amounts of oxidation than the 4f. Limitations of the methodology, as well as advantages of using the 5d relative to the 4f line are discussed.

  13. O CONCEITO DE PSICOPATIA ANALISADO PELA CRIMINOLOGIA CRÍTICA

    Directory of Open Access Journals (Sweden)

    Bruno dos Santos Silva

    2015-01-01

    Full Text Available The present investigation aims at the concept of psychopathy, from its creation, in the XIX century, to the authors who gave it the structure conceived by scientific community nowadays. Further, that concept will be analyzed by the means of some authors of the critical criminology. For that reason, this paper will employ Criminology concepts to interpret the conformation of the object psychopathy and the institutional consequences of its application.

  14. SORCE XPS Level 3 Solar Spectral Irradiance Daily Means V011 (SOR3XPSD) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SORCE XUV Photometer System (XPS) Solar Spectral Irradiance (SSI) Daily Data Product SOR3XPSD contains solar extreme ultraviolet irradiances in the 0.1 to 27 nm...

  15. X-ray photoemission spectroscopy (XPS) study of uranium, neptunium and plutonium oxides in silicate-based glasses

    International Nuclear Information System (INIS)

    Lam, D.J.; Veal, B.W.; Paulikas, A.P.

    1982-11-01

    Using XPS as the principal investigative tool, we are in the process of examining the bonding properties of selected metal oxides added to silicate glass. In this paper, we present results of XPS studies of uranium, neptunium, and plutonium in binary and multicomponent silicate-based glasses. Models are proposed to account for the very diverse bonding properties of 6+ and 4+ actinide ions in the glasses

  16. ISS Assessment of the Influence of Nonpore Surface in the XPS Analysis of Oil-Producing Reservoir Rocks

    Science.gov (United States)

    Leon; Toledo; Araujo

    1997-08-15

    The application of X-ray photoelectron spectroscopy (XPS) to oil-producing reservoir rocks is new and has shown that pore surface concentrations can be related to rock wettability. In the preparation of fresh fractures of rocks, however, some nonpore surface corresponding to the connection regions in the rocks is created and exposed to XPS. To assess the potential influence of this nonpore surface in the XPS analysis of rocks here we use ion scattering spectroscopy (ISS), which has a resolution comparable to the size of the pores, higher than that of XPS, with an ion gun of He+ at maximum focus. Sample charging effects are partially eliminated with a flood gun of low energy electrons. All the ISS signals are identified by means of a formula which corrects any residual charging on the samples. Three rock samples are analyzed by XPS and ISS. The almost unchanged ISS spectra obtained at different points of a given sample suggest that the nonpore surface created in the fracture process is negligibly small, indicating that XPS data, from a larger surface spot, represents the composition of true pore surfaces. The significant changes observed in ISS spectra from different samples indicate that ISS is sample specific. Copyright 1997Academic Press

  17. Surface and bulk composition of YBa 2Cu 3O 6+x compounds studied by XPS

    Science.gov (United States)

    Andersson, S. Lars T.; Otamiri, Jonathan C.

    1990-08-01

    YBa 2Cu 3O 6+ x compounds prepared by a formic acid route where characterized by XPS. The samples were investigated both after scraping in air and in vacuum to reveal the surface composition after partial degradation during short time air exposure and to gather data on the pure bulk state. The surface layer is characterized by the XPS data of O 1s = 530.8-531.5 eV, Y3d 5/2 = 157.5 eV, Ba3d 5/2 = 779.9 eV , Ba4d 5/2 = 89.4 eV and Cu2p 3/2 = 934.4 eV with a strong satellite structure at 942.5 eV. The data indicate the presence of barium hydroxide and carbonate, copper(II) oxide, the green phase and some yttrium compound. The bulk state is characterized by XPS data of O 1 s = 528.8 eV, Y3d 5/2 = 156.2 eV , Ba3d 5/2 = 778.6 eV , Ba4d 5/2 = 88.3 eV and Cu2p 3/2 = 932.6 eV without a satellite and a similar copper state as for the surface layer. There exist single states of yttrium and barium in the bulk, both copper(I) and copper(II) valence states and for oxygen possibly several components closely spaced accounting for the structurally different oxide ions.

  18. Combined DFT and XPS investigation of iodine anions adsorption on the sulfur terminated (001) chalcopyrite surface

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kui, E-mail: likui9606@stu.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Zhao, Yaolin, E-mail: zhaoyaolin@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Zhang, Peng, E-mail: zp32@qq.com [Sino Shaanxi Nuclear Industry Group, Xi’an 710100 (China); He, Chaohui, E-mail: hechaohui@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Deng, Jia, E-mail: djkokocase@stu.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Ding, Shujiang, E-mail: dingsj@mail.xjtu.edu.cn [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Shi, Weiqun, E-mail: shiwq@ihep.ac.cn [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2016-12-30

    Highlights: • Metal surface sites of (001)-S surface of chalcopyrite show significant chemical affinity to iodide and iodate. • The energetically favorable active site is copper for iodide adsorption and iron for iodate adsorption, respectively. • Iodate undergoes a dissociative adsorption on the copper site of chalcopyrite surface. - Abstract: The adsorption of iodine anions (iodide and iodate) on the sulfur terminated (001) chalcopyrite surface has been systematically investigated combining first-principles calculations based on density functional theory (DFT) with X-ray photoelectron spectroscopy (XPS) measurements. Based on the total energy calculations and geometric optimization, the thermodynamically preferred site was copper atom for iodide adsorption and iron atom for iodate adsorption, respectively. In the case of Cu site mode, the iodate underwent a dissociative adsorption, where one I−O bond of iodate ion was broken and the dissociative oxygen atom adsorbed on the adjacent sulphur site. Projected density of states (PDOS) analysis further clarified the interaction mechanism between active sites of chalcopyrite surface and adsorbates. In addition, full-range XPS spectra qualitatively revealed the presence of iodine on chalcopyrite surface. High resolution XPS spectra of the I 3d peaks after adsorption verified the chemical environment of iodine. The binding energies of 618.8 eV and 623.5 eV for I 3d{sub 5/2} peaks unveiled that the adsorption of iodide and iodate ions on copper-iron sulfide minerals was the result of formation of low solubility metal iodides precipitate. Also two I 3d peaks with low intensity around 618 eV and 630 eV might be related to the inorganic reduction of iodate to iodide by reducing S{sup 2−} ion of chalcopyrite.

  19. XPS response in the corrosion products analysis for copper exposed at clean air environment

    International Nuclear Information System (INIS)

    Mariaca, L.; Morcillo, M.; Feliu Jr, S.; Gonzalez, J.A.

    1998-01-01

    In this work is presented the obtained response for superficial analysis technique by X-ray photoelectron spectroscopy (XPS or ESCA), to determine the corrosion products formed during the copper exposure at environment without pollutants (clean air) at 50, 70 and 90 % of relative humidity at 35 Centigrade. One of the copper corrosion products most knew is Cu 2 O. This oxide is formed instantly to be exposed the copper at air. However in function of the exposure time and the relative humidity at it is exposed, the Cu 2 O oxide is transformed at Cu O and Cu(OH) 2 (Author)

  20. XPS study on the surface reaction of uranium metal with carbon monoxide at 200 degree C

    International Nuclear Information System (INIS)

    Wang Xiaoling; Fu Yibei; Xie Renshou; Huang Ruiliang

    1996-12-01

    The surface reaction of uranium metal with carbon monoxide at 200 degree C has been studied by X-ray photoelectron spectroscopy (XPS). The carbon monoxide adsorption on the surface oxide layer resulted in U4f peak shifting to the lower binding energy and the content of oxygen in the oxide is decreased. O/U radio decreases with increasing the exposure of carbon monoxide to the surface layer. The investigation indicated the surface layer of uranium metal was further reduced in the atmosphere of carbon monoxide at high temperature. (3 refs., 5 figs.)

  1. Combined application of XANES and XPS to study oxygen species adsorbed on Ag foil

    CERN Document Server

    Bukhtiyarov, V I; Kaichev, V V; Knop-Gericke, A; Mayer, R W; Schloegl, R

    2001-01-01

    Adsorbed oxygen species realized in the course of ethylene epoxidation over polycrystalline silver have been characterized by X-ray absorption near the edge structure and X-ray photoelectron spectroscopy. Namely, the combined application of XANES and XPS in similar UHV conditions using the same sample allowed us to assign an XAS feature to the nucleophilic and electrophilic oxygen. This is of great significance, since these species are suggested to be included into the active center for ethylene epoxidation. The differences in the oxygen-silver bonding of these oxygen species are discussed.

  2. Por uma metafí­sica do sublime

    OpenAIRE

    Martha de Almeida

    2010-01-01

    O sublime vem sendo analisado desde a antiguidade com uma marcante relaçáo com a tragédia, seja como gênero literário, seja por meio da Poética, de Aristóteles que nos traduz pela catarse o sentimento do sublime. Na modernidade, novos nomes foram chegando para colaborar com esta teoria: o próprio Hume, em seu ensaio Da tragédia, mostrou-se impressionado com a capacidade que esta forma de arte tem de produzir efeitos táo intensos no espectador. Porém, quem mais fortaleceu a análise do sublime ...

  3. A INFLUÊNCIA DO AMBIENTE DE VAREJO NAS COMPRAS POR IMPULSO EM AEROPORTOS

    Directory of Open Access Journals (Sweden)

    Jorge Brantes Ferreira

    2015-10-01

    Full Text Available O fluxo de passageiros em aeroportos comerciais internacionais cresce a cada ano. Mais passageiros representam mais consumidores em fluxo e mais negócios. As condições particulares dos aeroportos criam experiências de varejo únicas, com evidências de comportamento de compra por impulso. Este estudo avalia a importância do ambiente de varejo e das emoções no comportamento de compra por impulso de consumidores em aeroportos aplicando uma versão do modelo de Mohan et al. (2013. Os dados foram coletados por meio de uma survey envolvendo 218 clientes do duty free shop de um grande aeroporto brasileiro e analisados por equações estruturais. Os resultados indicam que o ambiente de compras exerce grande influência sobre as emoções do consumidor e que estas têm forte influência sobre sua vontade de comprar por impulso.

  4. XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

    International Nuclear Information System (INIS)

    Omran, Mamdouh; Fabritius, Timo; Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A.; El-Aref, Mortada; Elmanawi, Abd El-Hamid

    2015-01-01

    Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe 2 O 3 and P 2 O 5 contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe 3+ ) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases

  5. An XPS round robin investigation on analysis of wood pulp fibres and filter paper

    Science.gov (United States)

    Johansson, Leena-Sisko; Campbell, J. M.; Fardim, Pedro; Hultén, Anette Heijnesson; Boisvert, Jean-Philippe; Ernstsson, Marie

    2005-06-01

    X-ray photoelectron spectroscopy (XPS) has been applied to pulp and paper research for decades. However, there has been no attempt to standardise or even systematically compare experimental and analysis procedures, even though it is known that fibrous, nature-derived and insulating fibre materials pose remarkable challenges to reliable surface analysis. The experimental problems are mainly linked with neutralisation, energy resolution, contamination and X-ray induced degradation. We have tested applicability, reliability and reproducibility of XPS analysis on real pulp samples with varying lignin and extractives contents in a small round robin investigation. We also tested the instrumental set-ups with an acetone-extracted filter paper, used as a reference sample. The data, collected at four different laboratories with state-of-the-art instruments indicate that reproducible results can be obtained, despite minor differences in experimental and analysis procedures. However, we found that a specified sample handling procedure and limited X-ray exposure are crucial for reproducible, reliable data. Based on the round robin data we recommend dose restricted monochromatic measurements, a cellulosic in situ reference and a consistent sample handling procedure. The data confirms that a paper-based reference material and the correlation of high-resolution C 1s data with O/C atomic ratios can be used in testing instruments and experimental set-ups for pulp and paper materials.

  6. In-situ NAP XPS studies of dissociative water adsorption on GaAs(100) surfaces

    Science.gov (United States)

    Ptasinska, Sylwia; Zhang, Xueqiang

    2014-03-01

    In current semiconductor-based technology it is important to design and fabricate new materials in order to achieve specific well-defined properties and functionalities. Before such systems can be applied they first need to be understood, refined and controlled. Therefore, a basic knowledge about molecule/semiconductor surface interfaces is essential. In the present work dissociative water adsorption on the GaAs(100) surface is monitored using X-ray Photoelectron Spectroscopy (XPS) performed in situ under near ambient conditions. Firstly, the crystal surface is exposed to water vapor pressures ranging from UHV to 0.5 kPa. At elevated pressures an increase of oxygenation and hydroxylation of Ga surface atoms has been observed in the Ga2p XPS spectra. Moreover, intense signals obtained from molecularly adsorbed water molecules or water molecules adsorbed via hydrogen bond to surface OH groups have been also observed in the O1s spectra. Finally, the crystal surface is annealed up to 700 K at water vapor pressure of 0.01 kPa, which leads to desorption of physisorbed water molecules and further increase of surface oxidation. The research described herein was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Basic Energy Sciences, Office of Science, United States Department of Energy through grant number DE-FC02-04ER15533.

  7. Rondorfite-type structure — XPS and UV–vis study

    International Nuclear Information System (INIS)

    Dulski, M.; Bilewska, K.; Wojtyniak, M.; Szade, J.; Kusz, J.; Nowak, A.; Wrzalik, R.

    2015-01-01

    Highlights: • Structural and spectroscopic characterization of chlorosilicate mineral, rondorfite. • Characterization of main photoemission lines and valence band spectra. • The study of color origin’s using UV–vis spectroscopy. • Analysis of structural changes in context of origin of natural fluorescence. • Discussion of a new application possibilities of analyzed mineral - Abstract: This paper focuses on X-ray diffraction, X-ray photoelectron and UV–vis spectroscopy of two different (green, orange) rondorfite samples. The differences in the sample color originate from various O/Cl ratios. The orange color was found to be related either to the isomorphic substitution of Fe 3+ /Al 3+ for Mg 2+ , the presence of atypical [MgO 4 ] tetrahedrons in crystal structure or electronegativity of the sample. The tetrahedron is known to be very prone to accumulation of impurities and substitute atoms. Moreover, the XPS data showed tetrahedrally coordinated Mg 2+ and isomorphic substitution of Al 3+ /Fe 3+ for Mg 2+ , which influences local disordering and the point defects density and distribution. Non-equilibrium chlorine positions inside the crystal cages as well as Ca-Cl bonds have also been found. The XPS measurements as a function of temperature indicate occurrence of a structural transformation at about 770 K which is accompanied by a rotation of silicate tetrahedra within magnesiosilicate pentamer and luminescence disappearance

  8. Understanding the biomimetic properties of gallium in Pseudomonas aeruginosa: an XAS and XPS study.

    Science.gov (United States)

    Porcaro, F; Bonchi, C; Ugolini, A; Frangipani, E; Polzonetti, G; Visca, P; Meneghini, C; Battocchio, C

    2017-05-30

    Pyochelin (PCH) is a siderophore (extracellular chelator) produced by the pathogenic bacterium Pseudomonas aeruginosa (PAO). PCH is implicated in iron (Fe 3+ ) transport to PAO, and is crucial for its metabolism and pathogenicity. Due to the chemical similarity with Fe 3+ , gallium (Ga 3+ ) interferes with vital iron-dependent processes in bacterial cells, thereby opening new perspectives for the design of specific metal-based antibacterial drugs. However, the structural basis for the Fe 3+ -mimetic properties of Ga 3+ complexed with the PCH siderophore is still lacking. A precise knowledge of the coordination chemistry at the metal site is one of the topmost issues in the production of novel biomimetic metal-based drugs. Elucidation of this issue by means of a deep structural spectroscopic investigation could lead to an improved interference with, or a specific inhibition of, relevant biological pathways. For this reason, we applied Synchrotron Radiation induced X-ray Photoelectron Spectroscopy (SR-XPS) and X-ray Absorption Spectroscopy (XAS) to probe the electronic nature and coordination chemistry of Fe 3+ and Ga 3+ coordinative sites in PCH metal complexes. Combined XAFS and SR-XPS studies allow us to demonstrate that both Fe and Ga have the same valence state in Fe-PCH and Ga-PCH, and have the same octahedral coordination geometry. Moreover, a similar next neighbour distribution for Fe and Ga, resulting from the EXAFS data analysis, strongly supports similar coordination chemistry at the origin of the biomimetic behaviour of Ga.

  9. XPS analysis of the carbon fibers surface modified via HMDSO to carbon nanotube growth

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, L.D.R.; Gomes, M.C.B.; Trava-Airoldi, V.J.; Corat, E.J.; Lugo, D.C. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

    2016-07-01

    Full text: Carbon fibers (CF) have been widely used to reinforce structural composites. Due to their strength-to-weight properties, CF composites are finding increased structural uses in areas such as aerospace, aeronautical, automobile and others. The strength of the fiber-resin interface bond has been found to be the limiting factor to the mechanical properties of CF-epoxy materials, due to their non-polar nature that limit the affinity of CF to bind chemically to any matrix. The growth of carbon nanotubes (CNTs) on the surface of CF is a promising approach for improving mechanical, electrical and thermal properties of structural composites. However growing CNTs on CF presents some obstacles, such as diffusion of metal catalyst particles on CF, uneven CNT growth and loss of mechanical properties of CF. To avoid the diffusion of catalyst particles we modified the CF surface with hexamethyldisiloxane (HMDSO) at low temperature (400 °C), also preventing the loss of mechanical properties and allowing uniform CNTs growth. We deposited CNTs via floating catalyst method, with ferrocene providing the catalyst particle and the oxidative dehydrogenation reaction of acetylene providing the carbon. The CF surface modification was analyzed via X-ray photoelectron spectroscopy (XPS) and CNTs growth via scanning electron microscopy with field emission gun. The XPS analysis showed that HMDSO promotes the binding of oxygen to carbon and silicon present on CF surface, the chemical modification of the surface of the CF enables the uniform growth of carbon nanotubes. (author)

  10. XPS analysis of the carbon fibers surface modified via HMDSO to carbon nanotube growth

    International Nuclear Information System (INIS)

    Cardoso, L.D.R.; Gomes, M.C.B.; Trava-Airoldi, V.J.; Corat, E.J.; Lugo, D.C.

    2016-01-01

    Full text: Carbon fibers (CF) have been widely used to reinforce structural composites. Due to their strength-to-weight properties, CF composites are finding increased structural uses in areas such as aerospace, aeronautical, automobile and others. The strength of the fiber-resin interface bond has been found to be the limiting factor to the mechanical properties of CF-epoxy materials, due to their non-polar nature that limit the affinity of CF to bind chemically to any matrix. The growth of carbon nanotubes (CNTs) on the surface of CF is a promising approach for improving mechanical, electrical and thermal properties of structural composites. However growing CNTs on CF presents some obstacles, such as diffusion of metal catalyst particles on CF, uneven CNT growth and loss of mechanical properties of CF. To avoid the diffusion of catalyst particles we modified the CF surface with hexamethyldisiloxane (HMDSO) at low temperature (400 °C), also preventing the loss of mechanical properties and allowing uniform CNTs growth. We deposited CNTs via floating catalyst method, with ferrocene providing the catalyst particle and the oxidative dehydrogenation reaction of acetylene providing the carbon. The CF surface modification was analyzed via X-ray photoelectron spectroscopy (XPS) and CNTs growth via scanning electron microscopy with field emission gun. The XPS analysis showed that HMDSO promotes the binding of oxygen to carbon and silicon present on CF surface, the chemical modification of the surface of the CF enables the uniform growth of carbon nanotubes. (author)

  11. XPS and XAS investigation of condensed and adsorbed n-octane on a Cu(110) surface

    International Nuclear Information System (INIS)

    Weiss, K.; Oestroem, H.; Triguero, L.; Ogasawara, H.; Garnier, M.G.; Pettersson, L.G.M.; Nilsson, A.

    2003-01-01

    The electronic structure of n-octane adsorbed on Cu(110) is studied by using X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) in combination with cluster model calculations in the framework of density functional theory (DFT). The molecule is found to be well oriented on the surface, which is seen from the high degree of XAS dichroism. Saturated hydrocarbons are commonly considered to physisorb on metals such as Cu(110), but still the C 1s XAS spectra reveal large changes in the electronic structure of the adsorbed octane relative to the free molecule. We find that the XAS resonances corresponding to the molecular Rydberg-valence states are strongly quenched upon adsorption and that there is a significant hybridization of the molecular valence orbitals with the metal bands. In addition to a precise interpretation of the XAS spectra, we present details on the molecular orbital structure of the adsorbed octane molecule. We also discuss shifts in the relative binding energies of the chemically inequivalent carbon atoms in octane upon adsorption, which lead to a narrower XPS spectrum for the adsorbate than the condensed phase spectrum due to the existence of a new relaxation channel

  12. Formation of complexes between functionalized chitosan membranes and copper: A study by angle resolved XPS

    Energy Technology Data Exchange (ETDEWEB)

    Jurado-López, Belén [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain); Vieira, Rodrigo Silveira [Chemical Engineering Department, Universidade Federal do Ceará, UFC, 60455-760 Fortaleza, CE (Brazil); Rabelo, Rodrigo Balloni; Beppu, Marisa Masumi [School of Chemical Engineering, University of Campinas, UNICAMP, P.O. Box 6066, 13081-970 Campinas, SP (Brazil); Casado, Juan [Departamento de Química-Física, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain); Rodríguez-Castellón, Enrique, E-mail: castellon@uma.es [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga (Spain)

    2017-01-01

    Chitosan is a biopolymer with potential applications in various fields. Recently, it has been used for heavy metals removal like copper, due to the presence of amino and hydroxyl groups in its structure. Chitosan membranes were crosslinked with epichlorohydrin and bisoxirano and functionalized with chelating agents, such as iminodiacetic acid, aspartic acid and tris-(2-amino-ethyl) polyamine. These membranes were used for copper adsorption and the formed complexes were characterized. Thermal and crystalline properties of chitosan membranes were studied by TG-DCS and X-ray diffraction. Raman, XPS and FT-IR data confirmed that copper is linked to the modified chitosan membranes by the amino groups. The oxidation state of copper-chitosan membranes were also studied by angle resolved XPS, and by UV–Vis diffuse reflectance spectroscopy. - Highlights: • Chitosan membranes were crosslinked with epichlorohydrin and bisoxirano and functionalized with chelating agents. • The chelating agent were iminodiacetic acid, aspartic acid and tris-(2-amino-ethyl) polyamine. • The functionalized membranes were used for copper adsorption and studied by ARXPS, Raman, TG-DCS, FT-IR and XRD. • Spectroscopic data confirmed that copper is linked to the modified chitosan membranes by the amino groups.

  13. Structural, optical, XPS and magnetic properties of Zn particles capped by ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Iu.G., E-mail: yugmor@hotmail.com [Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Academician Osipyan Street 8, Chernogolovka, Moscow Region 142432 (Russian Federation); Belousova, O.V. [Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Academician Osipyan Street 8, Chernogolovka, Moscow Region 142432 (Russian Federation); Ortega, D., E-mail: daniel.ortega@imdea.org [Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco 28049, Madrid (Spain); Mafina, M.-K., E-mail: m.k.mafina@qmul.ac.uk [School of Engineering and Materials Science, Queen Mary University of London, Mile End, Eng, 231, London E1 4NS (United Kingdom); Kuznetcov, M.V., E-mail: maxim1968@mail.ru [Department of Chemistry, Materials Chemistry Research Centre, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

    2015-06-05

    Highlights: • Levitation-jet aerosol synthesis of Zn particles capped by ZnO nanoparticles (NPs). • TEM, XRD, UV–vis, FT-IR, Raman, XPS and magnetic characterization of the NPs. • Correlation between unit-cell volume of crystal lattice and maximum magnetization. - Abstract: Spherical zinc particles ranging from 42 to 760 nm in average size and capped with plate-like zinc oxide particles of 10–30 nm in sizes have been prepared by levitation-jet aerosol synthesis through condensation of zinc vapor in an inert/oxidizer gas flow. The nanoparticles have been characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), BET measurements, ultra violet visible (UV–vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray electron spectroscopy (XPS), superconducting quantum interference device (SQUID), and vibrating-sample magnetometer (VSM). Magnetic and XRD data indicate that the observed ferromagnetic ordering related to the changes in unit-cell volume of Zn in the Zn/ZnO interface of the nanoparticles. These results are in good correlation with the optical measurements data.

  14. Sol-gel synthesis and XPS study of vanadium-hydroquinone oxide bronze films

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenka, V. [Semiconductor Physics Institute, A. Gostauto 11, 01108 Vilnius (Lithuania); Vilnius Pedagogical University, Studentu 39, 08106 Vilnius (Lithuania); Tvardauskas, H.; Grebinskij, S.; Senulis, M.; Pasiskevicius, A. [Semiconductor Physics Institute, A. Gostauto 11, 01108 Vilnius (Lithuania); Volkov, V.; Zakharova, G. [Institute of Solid State Chemistry, Pervomaiskaia 91, 620219 Yekaterinburg (Russian Federation)

    2009-12-15

    A vanadium - hydroquinone oxide bronze has been synthesized by using a sol gel technology. The V{sub 2}O{sub 5} powder, hydrogen peroxide, and hydroquinone C{sub 6}H{sub 4}(OH){sub 2} were used as the starting materials to produce the bronze. At first the vanadium gel was made by the dissolving of vanadium pentoxide powder in hydrogen peroxide at 273 K. Then the solution was heated up to 350 K for the dissociation of peroxide complexes. An aqueous solution of hydroquinone was mixed with the formed gel in molar ratio 0.33:1. In this way the V{sub 2}O{sub 5{+-}}{sub {delta}}.nH{sub 2}O/HQ (HQ-hydroquinone) gel was synthesized. These gels are applied on the Ni pad and dried in an air (wet gel synthesis) or heated up to 580 K in air for 1 h for the water removal from gel (bronze production). The wet gel, as well as a bronze, was investigated by means of XPS method. Analysis of V-O region of XPS spectra shows that vanadium in both cases (wet gel and bronze) is in stable V{sup 5+} state. Oxygen in wet gel can be associated with V ions, hydroxide group and water. In bronze oxygen is connected with V and hydrogen (hydroxide). (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Characterization of Desulfovibrio desulfuricans biofilm on high-alloyed stainless steel: XPS and electrochemical studies

    Energy Technology Data Exchange (ETDEWEB)

    Dec, Weronika [Institute of Industrial Organic Chemistry, Branch Pszczyna, Doświadczalna Street 27, 43-200 Pszczyna (Poland); Mosiałek, Michał; Socha, Robert P. [Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek Street 8, 30-239 Kraków (Poland); Jaworska-Kik, Marzena [Department of Biopharmacy, Medical University of Silesia, Jedności Street 8, 41-200 Sosnowiec (Poland); Simka, Wojciech [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego 6 Street, 44-100 Gliwice (Poland); Michalska, Joanna, E-mail: joanna.k.michalska@polsl.pl [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego 6 Street, 44-100 Gliwice (Poland)

    2017-07-01

    Results on D. desulfuricans biofilm formation on austenitic-ferritic duplex (2205 DSS) and superaustenitic (904L) stainless steels are presented. Surface characterization including the structure, configuration and chemical composition of biofilms were carried out using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Electrochemical impedance spectroscopy (EIS) measurements were used to monitor the attachment activity of bacteria on the steels' surface and to determine the effect of bacteria on passivity. It was proved that investigated steels are rapidly colonized by bacteria. The presence of biofilm caused significant ennoblement of 904L steel surface, while retarded the attainment of high passive state of 2205 DSS. XPS analysis revealed significant sulphidation of the biofilm and its layered structure. Accumulation of sulphides and hydroxides was proved in the outermost layer, while the increasing contents of disulphides, organometallic and C-N bonds were detected in the internal part of the biofilm. Irreversible bondings between steel matrix and biofilm had also been observed. - Highlights: • High-alloyed steels are rapidly colonized by sulphate-reducing bacteria. • Higher Ni content stimulates more intensive biofilm growth. • Extracellular polymeric substances indelibly bind to the high-alloyed steels. • Sulphate-reducing bacteria caused irreversible sulphidation of passive films.

  16. XPS study of the surface chemistry of UO2 (111) single crystal film

    Science.gov (United States)

    Maslakov, Konstantin I.; Teterin, Yury A.; Popel, Aleksej J.; Teterin, Anton Yu.; Ivanov, Kirill E.; Kalmykov, Stepan N.; Petrov, Vladimir G.; Springell, Ross; Scott, Thomas B.; Farnan, Ian

    2018-03-01

    A (111) air-exposed surface of UO2 thin film (150 nm) on (111) YSZ (yttria-stabilized zirconia) before and after the Ar+ etching and subsequent in situ annealing in the spectrometer analytic chamber was studied by XPS technique. The U 5f, U 4f and O 1s electron peak intensities were employed for determining the oxygen coefficient kO = 2 + x of a UO2+x oxide on the surface. It was found that initial surface (several nm) had kO = 2.20. A 20 s Ar+ etching led to formation of oxide UO2.12, whose composition does not depend significantly on the etching time (up to 180 s). Ar+ etching and subsequent annealing at temperatures 100-380 °C in vacuum was established to result in formation of stable well-organized structure UO2.12 reflected in the U 4f XPS spectra as high intensity (∼28% of the basic peak) shake-up satellites 6.9 eV away from the basic peaks, and virtually did not change the oxygen coefficient of the sample surface. This agrees with the suggestion that a stable (self-assembling) phase with the oxygen coefficient kO ≈ 2.12 forms on the UO2 surface.

  17. Theoretical modeling of the uranium 4f XPS for U(VI) and U(IV) oxides

    Science.gov (United States)

    Bagus, Paul S.; Nelin, Connie J.; Ilton, Eugene S.

    2013-12-01

    A rigorous study is presented of the physical processes related to X-Ray photoelectron spectroscopy, XPS, in the 4f level of U oxides, which, as well as being of physical interest in themselves, are representative of XPS in heavy metal oxides. In particular, we present compelling evidence for a new view of the screening of core-holes that extends prior understandings. Our analysis of the screening focuses on the covalent mixing of high lying U and O orbitals as opposed to the, more common, use of orbitals that are nominally pure U or pure O. It is shown that this covalent mixing is quite different for the initial and final, core-hole, configurations and that this difference is directly related to the XPS satellite intensity. Furthermore, we show that the high-lying U d orbitals as well as the U(5f) orbital may both contribute to the core-hole screening, in contrast with previous work that has only considered screening through the U(5f) shell. The role of modifying the U-O interaction by changing the U-O distance has been investigated and an unexpected correlation between U-O distance and XPS satellite intensity has been discovered. The role of flourite and octahedral crystal structures for U(IV) oxides has been examined and relationships established between XPS features and the covalent interactions in the different structures. The physical views of XPS satellites as arising from shake processes or as arising from ligand to metal charge transfers are contrasted; our analysis provides strong support that shake processes give a more fundamental physical understanding than charge transfer. Our theoretical studies are based on rigorous, strictly ab initio determinations of the electronic structure of embedded cluster models of U oxides with formal U(VI) and U(IV) oxidation states. Our results provide a foundation that makes it possible to establish quantitative relationships between features of the XPS spectra and materials properties.

  18. Structural and XPS studies of PSi/TiO2 nanocomposites prepared by ALD and Ag-assisted chemical etching

    International Nuclear Information System (INIS)

    Iatsunskyi, Igor; Kempiński, Mateusz; Nowaczyk, Grzegorz; Jancelewicz, Mariusz; Pavlenko, Mykola; Załęski, Karol; Jurga, Stefan

    2015-01-01

    Highlights: • Porous silicon/TiO 2 nanocomposites have been investigated. • Morphology and chemical composition of PSi/TiO 2 nanocomposites were established. • Valence-band XPS maximums for PSi/TiO 2 nanocomposites were found and analyzed. - Abstract: PSi/TiO 2 nanocomposites fabricated by atomic layer deposition (ALD) and metal-assisted chemical etching (MACE) were investigated. The morphology and phase structure of PSi/TiO 2 nanocomposites were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) with an energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy. The mean size of TiO 2 nanocrystals was determined by TEM and Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical elemental composition by observing the behavior of the Ti 2p, O 1s and Si 2p lines. TEM, Raman spectroscopy and XPS binding energy analysis confirmed the formation of TiO 2 anatase phase inside the PSi matrix. The XPS valence band analysis was performed in order to investigate the modification of PSi/TiO 2 nanocomposites electronic structure. Surface defects states of Ti 3+ at PSi/TiO 2 nanocomposites were identified by analyzing of XPS valence band spectra

  19. [Analysis of XPS in the removal of Se(IV) from groundwater with pyrite].

    Science.gov (United States)

    Liu, Hong-fang; Qian, Tian-wei; Zhang, Min-gang

    2015-02-01

    Selenium (Se) is an elementary trace nutrient element for human but there is a very narrow range between deficit and toxic levels. Furthermore, excessive intake of Selenium is harmful for human. The product species of selenite which was removal by pyrite particles was studied in the present research In the experiments, the pyrite particles were prepared by the wet ball mill method, and surface analyses of pyrite before and after contact with Se(IV) were conducted using X-ray photoelectron spectroscopy (XPS). Besides, the prepared pyrite samples were also characterized using both X-ray diffraction (XRD) and scanning electron microscope (SEM). X-ray diffraction analysis indicated that the purity of the prepared pyrite particles was above 97%, and the characteristic diffraction peaks of the particles well matched with that of FeS2 crystalline. Scanning electron microscope determination showed the shape of the particles was approximate ball and the size was range from 80 to 180 nm. And thus the pyrite particles prepared by the wet ball mill method had less particle size, larger specific surface area and higher reactive ability. The batch experiments exhibited the pyrite particles were able to remove 95% of Se(IV) (20 mg x L(-1)) from water within 12 hours. And the kinetic tests indicated reaction process between pyrite and Se(IV) fits a pseudo-first order kinetic model, which gives a pseudo-first order rate constant(kobs) of 0.26 h(-1). XPS analyses were using the XPSPEAK program which has a Gaussian Lorentzian function. The results clearly displays that Se(IV) prefer to react with the surface-bound S2(2-) rather than reacted with the surface-bound Fe2+ of pyrite particles. From XPS graph, it can be seen that the binding energy of sulfur element and iron element composed of pyrite shifted to the left a little, which means expensive state of sulfur element and iron element appeared on the pyrite surface. Analysis of the oxidation state of Se on the surface of pyrite

  20. Physical and Chemical Behaviors of HCl on Ice Surface: Insights from an XPS and NEXAFS Study

    Science.gov (United States)

    Kong, X.; Waldner, A.; Orlando, F.; Birrer, M.; Artiglia, L.; Ammann, M.; Bartels-Rausch, T.

    2016-12-01

    Ice and snow play active roles for the water cycle, the energy budget of the Earth, and environmental chemistry in the atmosphere and cryosphere. Trace gases can be taken up by ice, and physical and chemical fates of the impurities could modify surface properties significantly and consequently influence atmospheric chemistry and the climate system. However, the understanding of chemical behaviour of impurities on ice surface are very poor, which is largely limited by the difficulties to apply high sensitivity experimental approaches to ambient air conditions, e.g. studies of volatile surfaces, because of the strict requirements of vacuum experimental conditions. In this study, we employed synchrotron-based X-ray photoelectron spectroscopy (XPS) and partial electron yield Near Edge X-ray Absorption Fine Structure (NEXAFS) in a state-of-the-art near-ambient pressure photoelectron (NAPP) spectroscopy end station. The NAPP enables to utilize the surface sensitive experimental methods, XPS and NEXAFS, on volatile surfaces, i.e. ice at temperatures approaching 0°C. XPS and NEXAFS together provide unique information of hydrogen bonding network, dopants surface concentration, dopant depth profile, and acidic dissociation on the surfaces1. Taking the advantages of the highly sensitive techniques, the adsorption, dissociation and depth profile of Hydrogen Chloride (HCl) on ice were studied. In brief, two states of Chloride on ice surface are identified from the adsorbed HCl, and they are featured with different depth profiles along the ice layers. Combining our results and previously reported constants from literatures (e.g. HCl diffusion coefficients in ice)2, a layered kinetic model has been constructed to fit the depth profiles of two states of Chloride. On the other side, pure ice and doped ice are compared for their surface structure change caused by temperature and the presence of HCl, which shows how the strong acid affect the ice surface in turn. 1. Orlando, F., et

  1. XPS determination of Mn oxidation states in Mn (hydr)oxides

    International Nuclear Information System (INIS)

    Ilton, Eugene S.; Post, Jeffrey E.; Heaney, Peter J.; Ling, Florence T.; Kerisit, Sebastien N.

    2016-01-01

    Graphical abstract: - Highlights: • Systematic fitting the XPS Mn3p, Mn2p, and Mn3s to determine oxidation states of Mn (hydr)oxides. • Analysis of using the Mn3s multiplet splitting for determining valence of Mn(hydr)oxides. • Provided an easy to implement method for determining Mn oxidation states using XPS. - Abstract: Hydrous manganese oxides are an important class of minerals that help regulate the geochemical redox cycle in near-surface environments and are also considered to be promising catalysts for energy applications such as the oxidation of water. A complete characterization of these minerals is required to better understand their catalytic and redox activity. In this contribution an empirical methodology using X-ray photoelectron spectroscopy (XPS) is developed to quantify the oxidation state of hydrous multivalent manganese oxides with an emphasis on birnessite, a layered structure that occurs commonly in soils but is also the oxidized endmember in biomimetic water-oxidation catalysts. The Mn2p 3/2 , Mn3p, and Mn3s lines of near monovalent Mn(II), Mn(III), and Mn(IV) oxides were fit with component peaks; after the best fit was obtained the relative widths, heights and binding energies of the components were fixed. Unknown multivalent samples were fit such that binding energies, intensities, and peak-widths of each oxidation state, composed of a packet of correlated component peaks, were allowed to vary. Peak-widths were constrained to maintain the difference between the standards. Both average and individual mole fraction oxidation states for all three energy levels were strongly correlated, with close agreement between Mn3s and Mn3p analyses, whereas calculations based on the Mn2p 3/2 spectra gave systematically more reduced results. Limited stoichiometric analyses were consistent with Mn3p and Mn3s. Further, evidence indicates the shape of the Mn3p line was less sensitive to the bonding environment than that for Mn2p. Consequently, fitting the

  2. X-ray photoelectron spectroscopy (XPS) and FTIR studies of vanadium barium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Majjane, Abdelilah [Laboratoire de Physico-Chimie des Matériaux Vitreux et Cristallisés, Université Ibn Tofail, Faculté des Sciences, Kénitra 14090 (Morocco); Chahine, Abdelkrim, E-mail: abdelkrimchahine@gmail.com [Laboratoire de Physico-Chimie des Matériaux Vitreux et Cristallisés, Université Ibn Tofail, Faculté des Sciences, Kénitra 14090 (Morocco); Et-tabirou, Mohamed [Laboratoire de Physico-Chimie des Matériaux Vitreux et Cristallisés, Université Ibn Tofail, Faculté des Sciences, Kénitra 14090 (Morocco); Echchahed, Bousselham [Laboratoire d' Electrochimie, Corrosion et Environnement, Université Ibn Tofail, Faculté des Sciences, Kénitra (Morocco); Do, Trong-On [Département de génie chimique, Université Laval, G1K 7P4 (Canada); Breen, Peter Mc [Département de chimie, Université Laval, G1K 7P4 (Canada)

    2014-01-15

    Barium vanadophosphate glasses, having composition 50BaO–xV{sub 2}O{sub 5}–(50 − x)P{sub 2}O{sub 5}, (x = 0–50 mol%), were prepared by conventional melt quench method. Density, molar volume and glass transition temperature (T{sub g}) were measured as a function of V{sub 2}O{sub 5} content. Structural investigation was done using XPS and FTIR spectroscopy. First, substitution of the P{sub 2}O{sub 5} by the V{sub 2}O{sub 5} in the metaphosphate 50BaO–50P{sub 2}O{sub 5} glass increases the density and T{sub g} and decreases the molar volume. When the amount of V{sub 2}O{sub 5} increases, all these properties show a reverse trend. XPS measurement found in the O1s, P2p, and V2p core level spectra indicate the presence of primarily P–O–P, P–O–V and V–O–V structural bonds, the asymmetry in the P 2p spectra indeed arises from the spin-orbit splitting of P 2p core level, and more than one valence state of V ions being present. IR spectroscopy reveals the depolymerization of the phosphate glass network by systematic conversion of metaphosphate chains into pyrophosphate groups and then orthophosphate groups. Even though metaphosphate to pyrophosphate conversion is taking place due to breaking of P–O–P linkages, formation of P–O–V and P–O–Ba linkages provide cross linking between short P-structural units, which make the glass network more rigid. Above 10–20 mol% V{sub 2}O{sub 5} content, network is highly depolymerized due to the formation of orthophosphate units and V–O–V bridge bonds, resulting in poor cross-linking, making the glass network less rigid. - Highlights: • Barium–vanadium–phosphate glasses. • Structure has been investigated by XPS and IR spectra. • Variation in structure and properties with substitution of V{sub 2}O{sub 5} for P{sub 2}O{sub 5}. • Conversion of metaphosphate to pyrophosphate and finally to orthophosphate. • Substitution of P–O–P linkages by P–O–V, P–O–Ba and V–O–V linkages.

  3. 2-Butyne on Si(0 0 1) at room temperature: An XPS and NEXAFS study

    Energy Technology Data Exchange (ETDEWEB)

    Bournel, F., E-mail: fabrice.bournel@upmc.fr [Laboratoire de Chimie Physique Matiere et Rayonnement, UMR CNRS 7614, Universite Pierre et Marie Curie, Paris 6, Paris (France); Gallet, J.-J.; Rochet, F. [Laboratoire de Chimie Physique Matiere et Rayonnement, UMR CNRS 7614, Universite Pierre et Marie Curie, Paris 6, Paris (France); Hennies, F. [MAX-Lab Synchrotron, Lund University, Lund (Sweden); Silly, M.; Sirotti, F. [Synchrotron SOLEIL, St Aubin (France)

    2011-04-15

    Research highlights: {yields} Adsorption of 2-butyne on Si(001)-2 x 1. {yields} 3D maps of real time Si2p and C1s XPS while dosing. {yields} NEXAFS C K edge spectra of 2-butyne on Si(001). {yields} 2-butyne is 'di-sigma' bound in a 'on-dimer' geometry on Si(001)-2 x 1 at room temperature. - Abstract: We present here a study of the adsorption of 2-butyne (CH{sub 3}-C{identical_to}C-CH{sub 3}) on the Si(0 0 1)-2 x 1 silicon surface at room temperature using synchrotron radiation photoemission spectroscopy (XPS) and X-ray absorption spectroscopy (NEXAFS). In particular, the Si2p and C1s core levels were followed by real-time photoemission (measuring while dosing). The intensity of the Si2p surface state component gradually diminishes with an increasing exposure to the gas. The C1s photoemission line is decomposed into two main components with their vibrational series, attributed to the two inner carbons (bonded to silicon) and the two methyl carbons (protruding into the vacuum), respectively. C1s real-time XPS indicates that the chemical bonding of the molecule does not change from low coverage to saturation coverage. NEXAFS spectroscopy performed at the C K-edge using linearly polarized radiation reveals the presence of a {pi}*(C=C) molecular orbital parallel to the surface, resulting from the opening of the triple C{identical_to}C bond and the formation of two {sigma}(Si-C) bonds. The attachment of the molecule via C-H bond scission (conserving the C{identical_to}C bond) is excluded. The clear-cut observation of a C=C bond, combined to our preceding angle-resolved UV photoemission spectroscopy (ARUPS) work [Bournel et al., Surf. Sci. 601 (2007) 3750] favors the on-dimer adsorption model at saturation ({approx}3 L).

  4. AVALIAÇÃO DA ATIVIDADE ANTIOXIDANTE IN VITRO DOS CHÁS MATE E VERDE ANTES E APÓS A BIOTRANSFORMAÇÃO POR LIPASES

    OpenAIRE

    Camila Morais Gonçalves da SILVA; Mário Antônio BRAGA; Viviane Roberta Vieira SOBRAL; Carlos Augusto Real MARTINEZ; Patrícia de Oliveira CARVALHO

    2012-01-01

    Os chás mate e verde, comuns na dieta brasileira, foram avaliados primeiramente quanto a sua composição: os polifenóis totais e os flavonóides totais das matrizes alimentares in natura foram quantificados por espectrofotometria, enquanto o perfil de composição foi analisado por espectrometria de massas (ESI-MS). Posteriormente, a atividade antioxidante foi avaliada por ensaios in vitro, antes e após a biotransformação enzimática por lipase de pâncreas de porco e lipase...

  5. CompulsÃo por compras: uma anÃlise psicossocial crÃtica acerca das subjetividades contemporÃneas

    OpenAIRE

    Rebeca Carvalho de Morais

    2011-01-01

    A construÃÃo subjetiva contemporÃnea apresenta-se marcadamente permeada pela lÃgica do mercado responsÃvel por fabricar â via IndÃstria cultural â os mais diversos estilos de vida a serem consumidos pelo homem. A partir deste contexto, reflete-se acerca dos novos transtornos hipermodernos, tendo por figura exemplar o comportamento compulsivo por compras, analisado a partir do referencial teÃrico da Escola de Frankfurt. O objetivo à compreender os sentidos da compulsÃo por compras, considerand...

  6. Plasma-oxidation of Ge(100)-surfaces characterized by MIES, UPS and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Wegewitz, Lienhard; Dahle, Sebastian; Maus-Friedrichs, Wolfgang [Institut fuer Energieforschung und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstr. 4, 38678 Clausthal-Zellerfeld (Germany); Hoefft, Oliver; Endres, Frank [Institut fuer Mechanische Verfahrenstechnik, Technische Universitaet Clausthal, Arnold-Sommerfeld-Str. 6, 38678 Clausthal-Zellerfeld (Germany); Vioel, Wolfgang [HAWK Goettingen, Fakultaet Naturwissenschaften und Technik, Von-Ossietzky-Str. 99, 37085 Goettingen (Germany)

    2011-07-01

    Cleaning and passivation of Germanium surfaces is of tremendous technological interest. Germanium has various applications, for example in complementary metal-oxide-semiconductor elements. It turned out to be difficult to prepare contamination free Germanium surfaces by methods of wet chemistry. Several attempts have been made preparing such surfaces by different plasma treatments. We report cleaning and passivation of Ge(100)-surfaces by dielectric barrier discharge plasma at ambient temperature in oxygen and in air studied by Metastable Induced Electron Spectroscopy (MIES) and Photoelectron Spectroscopy (UPS(He I) and XPS). The plasma treatment is carried out in a special high-vacuum chamber which operates up to ambient pressure and is directly connected to the ultra-high vacuum chamber including the analysis equipment. In summary the air plasma treatment as well as the oxygen plasma treatment result in contamination free GeO{sub 2} covered surfaces.

  7. XPS study of the process of oxygen gettering by thin films of PACVD boron

    Science.gov (United States)

    Ennaceur^1, M. M.; Terreault, B.

    2000-06-01

    Numerous collector samples have been exposed in the TdeV tokamak, either to plasma assisted chemical vapor boronization only, or to boronization plus tokamak power discharges. They have been analyzed by X-ray photoelectron spectroscopy (XPS) in order to characterize and better understand the process by which the boron-rich film getter ambient oxygen. It was found that the state of oxidation of the samples after boronization is the most reliable predictor of subsequent machine performance. The gettering capacity is high, on the order of 10 21 O/m 2, and affects a surprisingly thick layer (˜100 nm), but the oxide always remains substoichiometric (with a formula BO x, x < 1). The oxidation is clearly activated by the plasma, during both glow discharge deposition and power discharges, but in this respect the latter are much more effective than the former.

  8. XPS and AES investigations of the adhesive bonding properties of thin titanium coatings

    International Nuclear Information System (INIS)

    Moers, H.; Mohr, J.; Klewe-Nebenius, H.; Pfennig, G.

    1988-07-01

    The bonding properties of PMMA-microstructures on Ti-coated Cu-substrates after an oxidative treatment in alkaline hydrogenperoxide solution were investigated. In order to clarify the basic mechanism, surface analytical investigations by XPS-, AES-, and depth profile measurements have been performed. It was demonstrated that for optimum bonding a TiO 2 surface layer of ca. 30 nm thickness is necessary. Chemical effects as well as a mechanical bonding with open grain boundary structures (dimensions in the μm-range) could be ruled out as bonding mechanisms. A mechanical interlocking of the polymer with micropores (dimensions in the nm-range) of the oxidic overlayer is adopted as the most probable bonding mechanism. (orig.)

  9. Electrochemical capacity fading of polyaniline electrode in supercapacitor: An XPS analysis

    Directory of Open Access Journals (Sweden)

    Jinxing Deng

    2017-04-01

    Full Text Available To understand the electrochemical capacity fading of the polyaniline (PANI electrodes in supercapacitors, for the first time, their chemical structure change during electrochemical cycles was traced with XPS analysis after the HCl doped PANI electrodes were subjected to the cyclic voltammetry test in 1.0 M H2SO4 electrolyte for different cycle numbers. The results showed that the chlorine disappeared in the electrode surface, while the surface element contents of sulfur and oxygen increased with the electrochemical cycles increased. It demonstrated that the hydrolytic degradation of the PANI chains and exchange of dopant occurred during the electrochemical cycling, causing the fading in the mechanical and electrochemical performance of the PANI electrodes. This understanding should lead to better design of the conductive polymer-based energy storage devices.

  10. Spectral studies on sulfur poisoning of Pd/Mg{sub 6}Ni by NEXAFS and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, S., E-mail: s-yagi@nucl.nagoya-u.ac.jp [Department of Quantum Engineering, School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Synchrotron Radiation Center, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-0046 (Japan); Nambu, M.; Tsukada, C.; Ogawa, S. [Department of Quantum Engineering, School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Kutluk, G.; Namatame, H.; Taniguchi, M. [Synchrotron Radiation Center, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

    2013-02-15

    We have studied on the hydrogen storage materials based on Mg–Ni alloy and fabricated the sample constructed with the Pd thin layer (TL) on Mg{sub 6}Ni alloy substrate. The adsorption behavior of the dimethyl disulfide (DMS) molecules on the sample has been measured to reveal the sulfur poisoning of the Pd TL/Mg{sub 6}Ni by means of XPS and Sulfur K-edge NEXAFS techniques. The chemisorbed DMS, methanethiolate (MT) and atomic S have been observed on the surface. Especially, it is clear that some atomic S has been oxidized by air and detected the adsorbate of the SO{sub 3}{sup 2−} and SO{sub 4}{sup 2−} species. During exposure to the atmosphere, most of the adsorbed DMS and MT adsorbates desorb from the Pd TL surface. We thus conclude the Pd TL might be able to prevent the hydrogen storage materials from the sulfur poisoning.

  11. Spectral studies on sulfur poisoning of Pd/Mg6Ni by NEXAFS and XPS

    International Nuclear Information System (INIS)

    Yagi, S.; Nambu, M.; Tsukada, C.; Ogawa, S.; Kutluk, G.; Namatame, H.; Taniguchi, M.

    2013-01-01

    We have studied on the hydrogen storage materials based on Mg–Ni alloy and fabricated the sample constructed with the Pd thin layer (TL) on Mg 6 Ni alloy substrate. The adsorption behavior of the dimethyl disulfide (DMS) molecules on the sample has been measured to reveal the sulfur poisoning of the Pd TL/Mg 6 Ni by means of XPS and Sulfur K-edge NEXAFS techniques. The chemisorbed DMS, methanethiolate (MT) and atomic S have been observed on the surface. Especially, it is clear that some atomic S has been oxidized by air and detected the adsorbate of the SO 3 2− and SO 4 2− species. During exposure to the atmosphere, most of the adsorbed DMS and MT adsorbates desorb from the Pd TL surface. We thus conclude the Pd TL might be able to prevent the hydrogen storage materials from the sulfur poisoning.

  12. Polyamide microcapsules containing alginic acid: extractability of metal ions and surface characterization by XPS.

    Science.gov (United States)

    Asaki, M; Ichinose, T; Monjushiroh, H; Fukumoto, T; Watarai, H

    1998-01-01

    Polyamide microcapsules containing alginic acid as a water-soluble macromolecular ligand (Alg-MC) were prepared by the interfacial polycondensation of sebacoyldichloride with hexamethylenediamine in a w/o emulsion system. The mean diameter of the microcapsules was 1.2 microns. The extractabilities of Cu(II), Ni(II), Co(II) and Ag(I) into the Alg-MC were examined and the highest uptake was found for Cu(II). It was ascertained that not only the inner ligand solution but also the membrane can accumulate the metal ions. The surface composition of the microcapsules was characterized by X-ray photo-electron spectroscopy (XPS) and it was found that some functional groups of alginic acid were present at the surface penetrating the membrane.

  13. In Situ XANES/XPS Investigation of Doped Manganese Perovskite Catalysts

    Directory of Open Access Journals (Sweden)

    Daniel Mierwaldt

    2014-04-01

    Full Text Available Studying catalysts in situ is of high interest for understanding their surface structure and electronic states in operation. Herein, we present a study of epitaxial manganite perovskite thin films (Pr1−xCaxMnO3 active for the oxygen evolution reaction (OER from electro-catalytic water splitting. X-ray absorption near-edge spectroscopy (XANES at the Mn L- and O K-edges, as well as X-ray photoemission spectroscopy (XPS of the O 1s and Ca 2p states have been performed in ultra-high vacuum and in water vapor under positive applied bias at room temperature. It is shown that under the oxidizing conditions of the OER a reduced Mn2+ species is generated at the catalyst surface. The Mn valence shift is accompanied by the formation of surface oxygen vacancies. Annealing of the catalysts in O2 atmosphere at 120 °C restores the virgin surfaces.

  14. Electronic density of state of Mn-N thin films measured by XPS

    CERN Document Server

    Morio, K

    2003-01-01

    Polycrystalline thin films with an oriented direction of epsilon-Mn sub 4 N along the (111) axis and of eta-Mn sub 3 N sub 2 along the (113) axis were prepared as a single phase by RF reactive magnetron sputtering method. A comparison of XPS spectral analysis with discrete Variational-X alpha method showed that the N atoms in Mn-N compounds behave as a donor and govern the magnetic properties of the films. The epsilon-Mn sub 4 N films was a single phase perovskite type crystal with lattice parameter 0.386 nm, and this films had properties of the ferrimagnetism with 1.1 mu sub B per unit cell. The eta-Mn sub 3 N sub 2 films was face center tetragonal (a=0.4205 nm, c=1.2131 nm), and it had properties of antiferromagnetism with 0.4 mu sub B per unit cell. (author)

  15. Heat capacity measurements and XPS studies on uranium-lanthanum mixed oxides

    International Nuclear Information System (INIS)

    Venkata Krishnan, R.; Mittal, V.K.; Babu, R.; Senapati, Abhiram; Bera, Santanu; Nagarajan, K.

    2011-01-01

    Research highlights: → Heat capacity measurements were carried out on (U 1-y La y )O 2±x (y = 0.2, 0.4, 0.6, and 0.8) using differential scanning calorimeter (DSC) in the temperature range 298-800 K. → Enthalpy increment measurements were carried out on the above solid solution using high temperature drop calorimetry in the temperature range 800-1800 K. → Chemical states of U and La in the solid solutions of mixed oxides were determined using X-ray photoelectron spectroscopy (XPS). → The anomalous increase in the heat capacity is attributed to certain thermal excitation process namely Frenkel pair defect of oxygen. → From the XPS investigation, it is observed that the O/M ratio at the surface is higher than that to the bulk. → In uranium rich mixed oxide samples, the surface O/M is greater than 2 whereas that in La rich mixed oxides, it is less than 2, though the bulk O/M in all the samples are less than 2. - Abstract: Heat capacity measurements were carried out on (U 1-y La y )O 2±x (y = 0.2, 0.4, 0.6, and 0.8) using differential scanning calorimeter (DSC) in the temperature range 298-800 K. Enthalpy increment measurements were carried out on the above solid solutions using high temperature drop calorimetry in the temperature range 800-1800 K. Chemical states of U and La in the solid solutions of mixed oxides were determined using X-ray photoelectron spectroscopy (XPS). Oxygen to metal ratios of (U 1-y La y )O 2±x were estimated from the ratios of different chemical states of U present in the sample. Anomalous increase in the heat capacity is observed for (U 1-y La y )O 2±x (y = 0.4, 0.6 and 0.8) with onset temperatures in the range of 1000-1200 K. The anomalous increase in the heat capacity is attributed to certain thermal excitation process, namely, Frenkel pair defect of oxygen. The heat capacity value of (U 1-y La y )O 2±x (y = 0.2, 0.4, 0.6, and 0.8) at 298 K are 65.3, 64.1, 57.7, 51.9 J K -1 mol -1 , respectively. From the XPS investigations

  16. XPS and TEM study of W-DLC/DLC double-layered film

    International Nuclear Information System (INIS)

    Takeno, Takanori; Komiyama, Takao; Miki, Hiroyuki; Takagi, Toshiyuki; Aoyama, Takashi

    2009-01-01

    A double-layered film of tungsten-containing diamond-like carbon (W-DLC) and DLC, (W-DLC)/DLC, was investigated. A film of 1.6 μm in thickness was deposited onto silicon substrate. The investigate double-layered coating was deposited by using the combination of PECVD and co-sputtering of tungsten metal target. Structure, interface and chemical bonding state of the investigated film were analyzed by Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). From the results of the analyses, the structure of double-layered film is that amorphous phase of carbon is continued from DLC to W-DLC and tungsten metal clusters are dispersed in W-DLC layer.

  17. Investigation of Winter Atmospheric Aerosol Particles in Downtown Katowice using XPS and SEM

    Science.gov (United States)

    Wawros, A.; Talik, E.; Pastuszka, J. S.

    2003-08-01

    X-ray photoelectron spectroscopy (XPS) was used to determine the surface chemical composition of atmospheric particles (PM-10 and PM-2.5), collected in downtown Katowice, Upper Silesia, Poland, in the winter season (November and December 2000). Carbon- and oxygen-containing species dominated the particulate surface with traces of N, S, Si, Cl, Na, Zn, Al, Cu, Fe, Ca, K, Mg, Pb, and P present. Additionally, the size, morphology, and chemical composition of about 300 of the individual atmospheric particles were analyzed by high-resolution scanning electron microscopy and electron probe microanalysis. A number of aluminosilicates and metallic elements such as Fe, K, Mg, Zn, as well as rare earth elements, were detected by SEM. The results obtained show that the analyzed aerosol is of natural and anthropogenic origin. Particles containing sulfur compounds as well as oxygen and sodium in downtown Katowice come mainly from the east and southeast sectors.

  18. XPS study of PBO fiber surface modified by incorporation of hydroxyl polar groups in main chains

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Tao; Hu Dayong; Jin Junhong; Yang Shenglin [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Li Guang, E-mail: lig@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Jiang Jianming [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China)

    2010-01-15

    Dihydroxy poly(p-phenylene benzobisoxazole) (DHPBO), a modified poly(p-phenylene benzoxazole) (PBO) polymer containing double hydroxyl groups in polymer chains, was synthesized by copolymerization of 4,6-diamino resorcinol dihydrochloride (DAR), purified terephthalic acid (TA) and 2,5-dihydroxyterephthalic acid (DHTA). DHPBO fibers were prepared by dry-jet wet-spinning method. The effects of hydroxyl polar groups on the surface elemental compositions of PBO fiber were investigated by X-ray photoelectron spectroscopy (XPS). The results show that the ratio of oxygen/carbon on the surface of DHPBO fibers is higher than that on the surface of PBO fibers, which indicates the content of polar groups on the surface of DHPBO fiber increase compared with PBO fiber.

  19. Study on the surface reaction of uranium metal in hydrogen atmosphere with XPS

    International Nuclear Information System (INIS)

    Wang Xiaolin; Fu Yibei; Xie Renshou; Zuo Changming; Zhao Chunpei; Chen Hong

    1998-01-01

    The surface reactions of uranium metal in hydrogen atmosphere at 25 degree C and 200 degree C and effects of temperature and carbon monoxide to the hydriding reaction have been studied by X-ray photoelectron spectroscopy (XPS). The reaction between H 2 and uranium metal at 25 degree C leads to the further oxidation of surface layer of metal due to traces of water vapor. At 200 degree C, it may lead to the hydriding reaction of uranium and the hydriding increases with increasing exposure to H 2 in the initial stages. The U4f 7/2 binding energy of UH 3 has been found to be 378.6 eV. Investigation indicates carbon monoxide inhibits both the hydriding reaction and oxidation on the condition of H 2 -CO atmosphere

  20. Corrosion behaviour of Ni in aprotic solvents an electrochemical, XPS and AFM study

    International Nuclear Information System (INIS)

    Bellucci, F.; Monetta, T.; Capobianco, G.; Deganello, A.; Glisenti, A.; Moretti, G.

    1998-01-01

    Electrochemical and X-ray photoelectron spectroscopic (XPS) techniques have been used to study the passivation of nickel in 0.1 M H 2 SO 4 DMF and ACN solutions with different water content. Electrochemical results indicate the anodic formation of a thin, poor protective layer and the possibility of salt precipitation onto the metallic surface. ARXPS results indicate that while in the anodic film formed in DMF, Ni(OH) 2 constitute the superficial component under which a discontinuous layer of NiO and NiSO 4 is present. Ni(OH) 2 and NiSO 4 are the more superficial constituents in the passivation layer formed in ACN, while NiO becomes prevalent in the underlying layers. AFM images show that in both the solvents the sample surface is very dishomogeneous with flakes and fractures. (orig.)

  1. Quantitative analysis of Si1-xGex alloy films by SIMS and XPS depth profiling using a reference material

    Science.gov (United States)

    Oh, Won Jin; Jang, Jong Shik; Lee, Youn Seoung; Kim, Ansoon; Kim, Kyung Joong

    2018-02-01

    Quantitative analysis methods of multi-element alloy films were compared. The atomic fractions of Si1-xGex alloy films were measured by depth profiling analysis with secondary ion mass spectrometry (SIMS) and X-ray Photoelectron Spectroscopy (XPS). Intensity-to-composition conversion factor (ICF) was used as a mean to convert the intensities to compositions instead of the relative sensitivity factors. The ICFs were determined from a reference Si1-xGex alloy film by the conventional method, average intensity (AI) method and total number counting (TNC) method. In the case of SIMS, although the atomic fractions measured by oxygen ion beams were not quantitative due to severe matrix effect, the results by cesium ion beam were very quantitative. The quantitative analysis results by SIMS using MCs2+ ions are comparable to the results by XPS. In the case of XPS, the measurement uncertainty was highly improved by the AI method and TNC method.

  2. A comparative study of Mg and Pt contacts on semi-insulating GaAs: electrical and XPS characterization

    Czech Academy of Sciences Publication Activity Database

    Dubecký, F.; Kindl, Dobroslav; Hubík, Pavel; Mičušík, M.; Dubecký, M.; Boháček, P.; Vanko, G.; Gombia, E.; Nečas, V.; Mudroň, J.

    2017-01-01

    Roč. 395, Feb (2017), s. 131-135 ISSN 0169-4332 Institutional support: RVO:68378271 Keywords : semi-insulating GaAs * metal-semiconductor contact * interface * work function * electron transport * XPS Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.387, year: 2016

  3. Surface refinement and electronic properties of graphene layers grown on copper substrate: An XPS, UPS and EELS study

    Czech Academy of Sciences Publication Activity Database

    Siokou, A.; Ravani, F.; Karakalos, S.; Frank, Otakar; Kalbáč, Martin; Galiotis, C.

    2011-01-01

    Roč. 257, č. 23 (2011), s. 9785-9790 ISSN 0169-4332 R&D Projects: GA MŠk LC510; GA AV ČR IAA400400911 Institutional research plan: CEZ:AV0Z40400503 Keywords : graphene * XPS * EELS Subject RIV: CG - Electrochemistry Impact factor: 2.103, year: 2011

  4. AFM AND XPS Characterization of Zinc-Aluminum Alloy Coatings with Attention to Surface Dross and Flow Lines

    Science.gov (United States)

    Harding, Felipe A.; Alarcon, Nelson A.; Toledo, Pedro G.

    Surfaces of various zinc-aluminum alloy (Zn-Al) coated steel samples are studied with attention to foreign surface dross by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS/ESCA). AFM topographic maps of zinc-aluminum alloy surfaces free of dross reveal the perfect nanoscale details of two kinds of dendrites: branched and globular. In all magnifications the dendrites appear smooth and, in general, very clean. XPS analysis of the extreme surface of a Zn-Al sample reveals Al, Zn, Si and O as the main components. The XPS results show no segregation or separation of phases other than those indicated by the ternary Al-Zn-Si diagram. For surfaces of Zn-Al plagued with impurities, high resolution AFM topographic maps reveal three situations: (1) areas with well-defined dendrites, relatively free of dross; (2) areas with small, millimeter-sized black spots known as dross; and (3) areas with large black stains, known as flow lines. Dendrite deformation and dross accumulation increase notably in the neighborhood, apparently clean to the naked eye, of dross or flow lines. XPS results of areas with dross and flow lines indicate unacceptable high concentration of Si and important Si phase separation. These results, in the light of AFM work, reveal that dross and flow lines are a consequence of a high local concentration of Si from high melting point silica and silicate impurities in the Zn-Al alloy source.

  5. An in situ XPS study of L-cysteine co-adsorbed with water on polycrystalline copper and gold

    Science.gov (United States)

    Jürgensen, Astrid; Raschke, Hannes; Esser, Norbert; Hergenröder, Roland

    2018-03-01

    The interactions of biomolecules with metal surfaces are important because an adsorbed layer of such molecules introduces complex reactive functionality to the substrate. However, studying these interactions is challenging: they usually take place in an aqueous environment, and the structure of the first few monolayers on the surface is of particular interest, as these layers determine most interfacial properties. Ideally, this requires surface sensitive analysis methods that are operated under ambient conditions, for example ambient pressure x-ray photoelectron spectroscopy (AP-XPS). This paper focuses on an AP-XPS study of the interaction of water vapour and l-Cysteine on polycrystalline copper and gold surfaces. Thin films of l-Cysteine were characterized with XPS in UHV and in a water vapour atmosphere (P ≤ 1 mbar): the structure of the adsorbed l-Cysteine layer depended on substrate material and deposition method, and exposure of the surface to water vapour led to the formation of hydrogen bonds between H2O molecules and the COO- and NH2 groups of adsorbed l-Cysteine zwitterions and neutral molecules, respectively. This study also proved that it is possible to investigate monolayers of biomolecules in a gas atmosphere with AP-XPS using a conventional laboratory Al-Kα x-ray source.

  6. Electronic-transitions and excitations in solid C-70 studied by EELS and XPS c-1s satellite structures

    NARCIS (Netherlands)

    Han, Bo-ying; Yu, Li-ming; Hevesi, K.; Gensterblum, G.; Rudolf, P.; Pireaux, J.-J.; Thiry, P.A.; Caudano, R.; Lambin, Ph.; Lucas, A.A.

    1995-01-01

    The electronic transition and excitation properties of highly ordered C70 films have been studied by reflection electron-energy-loss spectroscopy (EELS) and x-ray photoemission spectroscopy (XPS) C 1s satellite structures. The EELS study revealed a total of 11 features in the energy-loss range 1–40

  7. Comparing XPS on bare and capped ZrN films grown by plasma enhanced ALD: Effect of ambient oxidation

    Science.gov (United States)

    Muneshwar, Triratna; Cadien, Ken

    2018-03-01

    In this article we compare x-ray photoelectron spectroscopy (XPS) measurements on bare- and capped- zirconium nitride (ZrN) films to investigate the effect of ambient sample oxidation on the detected bound O in the form of oxide ZrO2 and/or oxynitride ZrOxNy. ZrN films in both bare- and Al2O3/AlN capped- XPS samples were grown by plasma-enhanced atomic layer deposition (PEALD) technique using tetrakis dimethylamino zirconium (TDMAZr) precursor, forming gas (5% H2, rest N2) inductively coupled plasma (ICP), and as received research grade process gases under identical process conditions. Capped samples were prepared by depositing 1 nm thick PEALD AlN on ZrN, followed by additional deposition of 1 nm thick ALD Al2O3, without venting of ALD reactor. On bare ZrN sample at room temperature, spectroscopic ellipsometry (SE) measurements with increasing ambient exposure times (texp) showed a self-limiting surface oxidation with the oxide thickness (dox) approaching 3.7 ± 0.02 nm for texp > 120 min. In XPS data measured prior to sample sputtering (tsput = 0), ZrO2 and ZrOxNy were detected in bare- samples, whereas only ZrN and Al2O3/AlN from capping layer were detected in capped- samples. For bare-ZrN samples, appearance of ZrO2 and ZrOxNy up to sputter depth (dsput) of 15 nm in depth-profile XPS data is in contradiction with measured dox = 3.7 nm, but explained from sputtering induced atomic inter-diffusion within analyzed sample. Appearance of artifacts in the XPS spectra from moderately sputtered (dsput = 0.2 nm and 0.4 nm) capped-ZrN sample, provides an evidence to ion-bombardment induced modifications within analyzed sample.

  8. Cryogenic XPS study of fast-frozen sulfide minerals: Flotation-related adsorption of n-butyl xanthate and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Mikhlin, Yuri, E-mail: yumikh@icct.ru [Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of sciences, Akademgorodok, 50/24, Krasnoyarsk 660036 (Russian Federation); Karacharov, Anton; Tomashevich, Yevgeny [Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of sciences, Akademgorodok, 50/24, Krasnoyarsk 660036 (Russian Federation); Shchukarev, Andrey [Department of Chemistry, Umeå University, Umeå SE-901 87 (Sweden)

    2016-01-15

    Highlights: • Mineral/aqueous solution interfaces were studied with quasi in situ cryo-XPS. • Dibutyl dixanthogen was the major xanthate adsorption product on pyrite. • Dixanthogen and minor cuprous xanthate were uptaken by chalcopyrite. • Xanthate was chemisorbed at PbS. • Ice-repellent character of hydrophobic particles caused charging effects in XPS. - Abstract: Cryogenic XPS of wet particulate samples separated via centrifugation and fast-frozen allows quasi in situ examination of solid surfaces, adsorbates, and reaction products, largely preventing the loss both of volatiles and hydrated species at mineral/water interfaces. Here, the cryo-XPS has been applied to characterize the surfaces and interfacial layers of natural pyrite (FeS{sub 2}), chalcopyrite (CuFeS{sub 2}), and galena (PbS) in solutions of a common flotation collector, potassium n-butyl xanthate (KBX), in conjunction with zeta-potential measurement. It was found, in particular, that dibutyl dixanthogen was the major adsorbate at pyrite in 0.1 mM KBX and 10 mM KBX solutions; dixanthogen and cuprous xanthate in the next stage were formed on chalcopyrite, and predominant chemisorbed butyl xanthate was present at galena, including in 10 mM KBX solution. The results may suggest that the production of dixanthogens at the interface has been underestimated while the quantities of surface metal xanthates could be over evaluated in previous studies. Pronounced differential charging effects were observed in the XPS experiment for the samples moderately hydrophobized by the xanthate treatment; we proposed that the effect was due to electrically isolated mineral particles with hydrophobic and ice-repellent surfaces, which retained, however, some frozen water islets.

  9. Quantifying the Impact of Nanoparticle Coatings and Nonuniformities on XPS Analysis: Gold/Silver Core-Shell Nanoparticles.

    Science.gov (United States)

    Wang, Yung-Chen; Engelhard, Mark H; Baer, Donald R; Castner, David G

    2016-04-05

    Spectral modeling of photoelectrons can serve as a valuable tool when combined with X-ray photoelectron spectroscopy (XPS) analysis. Herein, a new version of the NIST Simulation of Electron Spectra for Surface Analysis (SESSA 2.0) software, capable of directly simulating spherical multilayer NPs, was applied to model citrate stabilized Au/Ag-core/shell nanoparticles (NPs). The NPs were characterized using XPS and scanning transmission electron microscopy (STEM) to determine the composition and morphology of the NPs. The Au/Ag-core/shell NPs were observed to be polydispersed in size, nonspherical, and contain off-centered Au-cores. Using the average NP dimensions determined from STEM analysis, SESSA spectral modeling indicated that washed Au/Ag-core-shell NPs were stabilized with a 0.8 nm layer of sodium citrate and a 0.05 nm (one wash) or 0.025 nm (two wash) layer of adventitious hydrocarbon, but did not fully account for the observed XPS signal from the Au-core. This was addressed by a series of simulations and normalizations to account for contributions of NP nonsphericity and off-centered Au-cores. Both of these nonuniformities reduce the effective Ag-shell thickness, which effect the Au-core photoelectron intensity. The off-centered cores had the greatest impact for the particles in this study. When the contributions from the geometrical nonuniformities are included in the simulations, the SESSA generated elemental compositions that matched the XPS elemental compositions. This work demonstrates how spectral modeling software such as SESSA, when combined with experimental XPS and STEM measurements, advances the ability to quantitatively assess overlayer thicknesses for multilayer core-shell NPs and deal with complex, nonideal geometrical properties.

  10. Celulitis por citomegalovirus

    Directory of Open Access Journals (Sweden)

    A. Ruiz Lascano

    2002-12-01

    Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.

  11. Nanocrystalline GdAlO{sub 3}: XPS, EPR and magnetic susceptibility studies

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Dimitar [University of Food Technologies, Department of Inorganic and Physical Chemistry, Plovdiv (Bulgaria)

    2011-09-15

    Nanocrystalline gadolinium monoaluminate (GdAlO{sub 3}) has been synthesized by sol-gel method after sintering the precursor gel at 950 C. The microstructural features have been proved by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray analysis (EDX). The XRD pattern confirms the formation of single-phase GdAlO{sub 3} while EDX shows that this nanomaterial is stoichiometric; the average size of the nanoparticles is 40 nm. X-ray photoelectron spectroscopy (XPS) has been used to study the chemical composition and bonding in the as-prepared samples. The binding energies of core-level electrons in Gd, Al and O in GdAlO{sub 3} nanopowder have been found slightly shifted compared to the corresponding values of the same elements. The electron paramagnetic resonance (EPR) spectra at 9.23 GHz (X-band) and different temperatures indicate the existence of magnetically concentrated solid containing Gd{sup 3+} ions. Neel temperature, T{sub N} =3.993 K, effective Bohr magneton number, {mu} {sub eff}=8.18, and constant of magnetic exchange interaction, J{sub ex}=-0.069 cm {sup -1}, have been determined from DC magnetic susceptibilities measured in the range 2-300 K. (orig.)

  12. XPS analysis of PE and EVA samples irradiated at different γ-doses

    Science.gov (United States)

    Dorey, Samuel; Gaston, Fanny; Marque, Sylvain R. A.; Bortolotti, Benjamin; Dupuy, Nathalie

    2018-01-01

    The principal plastic materials used for the fluid contact and storage in the biopharmaceutical industry are mainly made up of semi-crystalline polymers, polyolefins, PVC, Siloxane and PET. The polyethylene (PE) and the polypropylene (PP) are often used as fluid contact in multi-layer materials like films. As one sterilisation way of single-use plastic devices used in medical and pharmaceutical fields can take place via γ-irradiation, the effect of sterilization on plastics must be investigated. The irradiation process leads to the production of radicals, which can generate changes in the polymer structure and on the polymer surface. It is well known that the presence of oxygen with free radicals precede the generation of peroxide species so called ROS (reactive oxygen species) which are highly reactive. The purpose of this work is to investigate the γ-rays impact on the surface of PE (polyethylene) and EVA (polyethylene vinyl alcohol) based films when ionized at different doses. X-ray Photoelectron Spectroscopy (XPS) was applied to determine the surface compositions of the polymers to highlight the different chemical moieties generated during the γ-irradiation process and to monitor the potential presence of the ROS.

  13. XPS characterization of (copper-based) coloured stains formed on limestone surfaces of outdoor Roman monuments

    Science.gov (United States)

    2012-01-01

    Limestone basements holding bronzes or other copper alloys artefacts such as sculptures, decorations and dedicatory inscriptions are frequently met both in modern and ancient monuments. In outdoor conditions, such a combination implies the corrosion products of the copper based alloy, directly exposed to rainwater, will be drained off and migrate through the porous surfaces, forming stains of different colours and intensities, finally causing the limestone structures to deteriorate. In this work we have analysed samples from two modern limestone monuments in Rome, the Botticino surfaces of the ‘Vittoriano’ (by G.Sacconi, 1885-1911- Piazza Venezia) and the travertine basement of the ‘Statua dello Studente’ (by A.Cataldi, 1920- University city, La Sapienza), and focussed our investigation on the chemical composition of the copper-stained zones using XPS (X-ray Photoelectron Spectroscopy) as a surface-specific technique. Based on observations reporting on the structure and bonding at the calcite surfaces we have identified copper complexes and mixed calcium/copper carbonates associated with the stains, as well as the chemical state of other elements therein included, and related the compositional changes with differences in chromatic characteristics and sampling locations. PMID:22594435

  14. Chemistry Characterization of Jet Aircraft Engine Particulate by XPS: Results from APEX III

    Science.gov (United States)

    Vander Wal, Randy L.; Bryg, Victoria M.

    2014-01-01

    This paper reports XPS analysis of jet exhaust particulate from a B737, Lear, ERJ, and A300 aircraft during the APEX III NASA led field campaign. Carbon hybridization and bonding chemistry are identified by high-resolution scans about the C1s core-shell region. Significant organic content as gauged by the sp3/sp2 ratio is found across engines and platforms. Polar oxygen functional groups include carboxylic, carbonyl and phenol with combined content of 20 percent or more. By lower resolution survey scans various elements including transition metals are identified along with lighter elements such as S, N, and O in the form of oxides. Burning additives within lubricants are probable sources of Na, Ba, Ca, Zn, P and possibly Sn. Elements present and their percentages varied significantly across all engines, not revealing any trend or identifiable cause for the differences, though the origin is likely the same for the same element when observed. This finding suggests that their presence can be used as a tracer for identifying soots from aircraft engines as well as diagnostic for monitoring engine performance and wear.

  15. XPS-Characterization of Heterometallic Coordination Compounds with Optically Active Ligands

    Directory of Open Access Journals (Sweden)

    Yenny Ávila-Torres

    2013-01-01

    Full Text Available The heterometallic optical complexes [Cu2Co(S,S(+cpse3(H2O3]·4H2O (1 and [Cu2Ni(S,S(+cpse3(H2O3]·10H2O (2 were obtained from the mononuclear copper(II compound by the addition of nickel(II or cobalt(II chlorides, where (H2cpse is the acetyl amino alcohol derivative N-[2-hydroxy-1(R-methyl-2(R-phenylethyl]-N-methylglycine. In comparison with the homotrinuclear copper(II compound [Cu3(S,S(+cpse3(H2O3]·8H2O reported previously, the substitution of a copper(II atom by one cobalt(II ion gave place to a heterotrinuclear compound 1, which presents ferromagnetic-antiferromagnetic behaviour. When substituting a copper(II by a nickel(II ion, the trinuclear compound 2 showed an antiferromagnetic coupling. The magnetic behaviour of the heterotrinuclear compounds is driven by the nature of the metal ion which was introduced in the copper(II triangular array. The ligand and its coordination compounds were characterized by IR, UV-Vis-NIR. Their chemical was confirmed by photoelectron spectroscopy (XPS.

  16. XPS analysis of 440C steel surfaces lubricated with perfluoropolyethers under sliding conditions in high vacuum

    Science.gov (United States)

    Herrera-Fierro, Pilar; Masuko, Masabumi; Jones, William R., Jr.; Pepper, Stephen V.

    1994-01-01

    This work presents the results of the X-Ray Photoelectron Spectroscopy (XPS) analysis of AISI 440C ball surfaces lubricated with perfluoropolyether (PFPE) oils after friction experiments under sliding conditions at high load in air and vacuum environments. The PFPE lubricants tested were Demnum S100, Fomblin Z-25, and Krytox 143AB. It was found that all the PFPE lubricants were degraded by sliding contact causing the formation of inorganic fluorides on the metallic surfaces and a layer of organic decomposition products. KRYTOX 143AB was the least reactive of the three lubricants tested. It was also found that metal fluoride formed at off-scar areas. This suggests the formation of reactive species, such as COF2 or R(sub f)COF, during sliding experiments, which can diffuse through the lubricant film and react with the metallic surfaces away from the contact region. Comparison of reference specimens before sliding with those that had undergone the sliding tests showed that the amount of non-degraded PFPE remaining on the surface of the balls after the sliding experiments was greater than that of the balls without sliding.

  17. XPS analysis of the effect of fillers on PTFE transfer film development in sliding contacts

    Science.gov (United States)

    Blanchet, T. A.; Kennedy, F. E.; Jayne, D. T.

    1993-01-01

    The development of transfer films atop steel counterfaces in contact with unfilled and bronze-filled PTFE has been studied using X-ray photoelectron spectroscopy. The sliding apparatus was contained within the vacuum of the analytical system, so the effects of the native oxide, hydrocarbon, and adsorbed gaseous surface layers of the steel upon the PTFE transfer behavior could be studied in situ. For both the filled and the unfilled PTFE, cleaner surfaces promoted greater amounts of transfer. Metal fluorides, which formed at the transfer film/counterface interface, were found solely in cases where the native oxide had been removed to expose the metallic surface prior to sliding. These fluorides also were found at clean metal/PTFE interfaces formed in the absence of frictional contact. A fraction of these fluorides resulted from irradiation damage inherent in XPS analysis. PTFE transfer films were found to build up with repeated sliding passes, by a process in which strands of transfer filled in the remaining counterface area. Under these reported test conditions, the transfer process is not expected to continue atop previously deposited transfer films. The bronze-filled composite generated greater amounts of transfer than the unfilled PTFE. The results are discussed relative to the observed increase in wear resistance imparted to PTFE by a broad range of inorganic fillers.

  18. XPS and XAS investigation of condensed and adsorbed n-octane on a Cu(110) surface

    CERN Document Server

    Weiss, K; Triguero, L; Ogasawara, H; Garnier, M G; Pettersson, L G M; Nilsson, A

    2003-01-01

    The electronic structure of n-octane adsorbed on Cu(110) is studied by using X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) in combination with cluster model calculations in the framework of density functional theory (DFT). The molecule is found to be well oriented on the surface, which is seen from the high degree of XAS dichroism. Saturated hydrocarbons are commonly considered to physisorb on metals such as Cu(110), but still the C 1s XAS spectra reveal large changes in the electronic structure of the adsorbed octane relative to the free molecule. We find that the XAS resonances corresponding to the molecular Rydberg-valence states are strongly quenched upon adsorption and that there is a significant hybridization of the molecular valence orbitals with the metal bands. In addition to a precise interpretation of the XAS spectra, we present details on the molecular orbital structure of the adsorbed octane molecule. We also discuss shifts in the relative binding energies of the ...

  19. Parameter setting for peak fitting method in XPS analysis of nitrogen in sewage sludge

    Science.gov (United States)

    Tang, Z. J.; Fang, P.; Huang, J. H.; Zhong, P. Y.

    2017-12-01

    Thermal decomposition method is regarded as an important route to treat increasing sewage sludge, while the high content of N causes serious nitrogen related problems, then figuring out the existing form and content of nitrogen of sewage sludge become essential. In this study, XPSpeak 4.1 was used to investigate the functional forms of nitrogen in sewage sludge, peak fitting method was adopted and the best-optimized parameters were determined. According to the result, the N1s spectra curve can be resolved into 5 peaks: pyridine-N (398.7±0.4eV), pyrrole-N(400.5±0.3eV), protein-N(400.4eV), ammonium-N(401.1±0.3eV) and nitrogen oxide-N(403.5±0.5eV). Based on the the experimental data obtained from elemental analysis and spectrophotometry method, the optimum parameters of curve fitting method were decided: background type: Tougaard, FWHM 1.2, 50% Lorentzian-Gaussian. XPS methods can be used as a practical tool to analysis the nitrogen functional groups of sewage sludge, which can reflect the real content of nitrogen of different forms.

  20. Core-level XPS spectra of fullerene, highly oriented pyrolitic graphite, and glassy carbon

    CERN Document Server

    Leiro, J A; Laiho, T; Batirev, I G

    2003-01-01

    The C 1s spectra of fullerene C sub 6 sub 0 , highly oriented pyrolitic graphite (HOPG) and amorphous carbon (a-C) have been measured using X-ray photoemission. The assumed background due to the inelastic scattering of electrons of these spectra has been subtracted by the Tougaard's method. The relative intensities and the energy positions for the core-level satellites have been determined. For C sub 6 sub 0 , a comparison of the low energy pi type shake-up satellites gives good agreement between theory and experiment. Also, the energies of these features for fullerene and glassy carbon are very similar, whereas the corresponding energies for HOPG are somewhat larger, presumably, because of the higher density of the latter. Moreover, the atomic force microscopy (AFM) study indicates that the C sub 6 sub 0 samples consist of a thick layer of large clusters on the Si(111) surface, which is in line with the molecular character of the XPS spectrum. Furthermore, the broad high energy satellite does not consist of ...

  1. Interfacial chemistry of a perfluoropolyether lubricant studied by XPS and TDS

    Science.gov (United States)

    Herrera-Fierro, Pilar C.; Jones, William R., Jr.; Pepper, Stephen V.

    1992-01-01

    The interfacial chemistry of Fomblin Z25, a commercial perfluoropolyether used as lubricant for space applications, with different metallic surfaces: 440C steel, gold and aluminum was studied. Thin layers of Fomblin Z25 were evaporated onto the oxide-free substrates and the interfacial chemistry studied using XPS and TDS. The reactions were induced by heating the substrate and by rubbing the substrate with a steel ball. Gold was found to be completely unreactive towards Fomblin at any temperature. Reaction at room temperature was observed only in the case of the aluminum substrate, the most reactive towards Fomblin Z25 of the substrates studied. It was necessary to heat the 440C steel substrate to 190 degree C to induce decomposition of the fluid. The degradation of the fluid was indicated by the formation of a debris layer at the interface. This debris layer, composed of inorganic and organic reaction products, when completely formed, passivated the surface from further attack to the Fromblin on top. The tribologically induced reactions on 440C steel formed a debris layer of similar chemical characteristics to the thermally induced layer. In all cases, the degradation reaction resulted in preferential consumption of the difluoroformyl carbon (-OCF2O-).

  2. Surface science approach to Pt/carbon model catalysts: XPS, STM and microreactor studies

    Science.gov (United States)

    Motin, Abdul Md.; Haunold, Thomas; Bukhtiyarov, Andrey V.; Bera, Abhijit; Rameshan, Christoph; Rupprechter, Günther

    2018-05-01

    Pt nanoparticles supported on carbon are an important technological catalyst. A corresponding model catalyst was prepared by physical vapor deposition (PVD) of Pt on sputtered HOPG (highly oriented pyrolytic graphite). The carbon substrate before and after sputtering as well as the Pt/HOPG system before and after Pt deposition and annealing were examined by XPS and STM. This yielded information on the surface density of defects, which serve as nucleation centres for Pt, and on the size distribution (mean size/height) of the Pt nanoparticles. Two different model catalysts were prepared with mean sizes of 2.0 and 3.6 nm, both turned out to be stable upon UHV-annealing to 300 °C. After transfer into a UHV-compatible flow microreactor and subsequent cleaning in UHV and under mbar pressure, the catalytic activity of the Pt/HOPG model system for ethylene hydrogenation was examined under atmospheric pressure flow conditions. This enabled to determine temperature-dependent conversion rates, turnover frequencies (TOFs) and activation energies. The catalytic results obtained are in line with the characteristics of technological Pt/C, demonstrating the validity of the current surface science based model catalyst approach.

  3. Embolia pulmonar por polimetilmetacrilato

    OpenAIRE

    Héctor Gómez Santa María; Mauro García Aurelio; Yanina Castillo Costa; Víctor Mauro; Carlos Barrero

    2009-01-01

    Los primeros registros de embolia pulmonar por polimetilmetacrilato se publicaron recientemente (2003) y desde entonces se describieron no más de 15 casos. Se presenta el caso de un paciente joven a quien dos meses antes de la consulta se le había efectuado una vertebroplastia percutánea con polimetilmetacrilato. Por síntomas pleuríticos se le realizó una radiografía de tórax, que evidenció múltiples imágenes radioopacas en ambos campos pulmonares. La embolia pulmonar por polimetilmetacrilato...

  4. Violência sexual por parceiro íntimo entre homens e mulheres no Brasil urbano, 2005

    OpenAIRE

    Schraiber,Lilia Blima; D'Oliveira,Ana Flávia P L; França Junior,Ivan

    2008-01-01

    OBJETIVO: Estimar a prevalência de violência sexual por parceiro íntimo entre homens e mulheres da população urbana brasileira e fatores a ela associados. MÉTODOS: Os dados analisados fazem parte de pesquisa realizada em 1998 e 2005 no Brasil, em população urbana. Os dados foram obtidos por meio de questionários aplicados a amostra representativa de 5.040 indivíduos, homens e mulheres de 16 a 65 anos. Análise descritiva foi realizada com dados ponderados, usando-se os testes F design-based, c...

  5. Adoção de Crianças por Casais Homossexuais: As Representações Sociais

    OpenAIRE

    Santos, José Victor De Oliveira; Araújo, Ludgleydson Fernandes de; Negreiros, Fauston; Cerqueira-Santos, Elder

    2018-01-01

    Resumo A presente pesquisa objetivou identificar as representações sociais da adoção por casais homoafetivos na realidade brasileira. Participaram 589 adultos, de ambos os sexos, com idades entre 18 e 69 anos (M= 27,43, DP= 9,0) de diferentes regiões do país. Utilizaram-se entrevistas estruturadas e questionários sociodemográficos que foram analisados pelo software Iramuteq, que por sua vez apreendeu as representações sociais em classes de proximidade lexical. Os resultados apontaram, na Clas...

  6. Embolia pulmonar por polimetilmetacrilato

    Directory of Open Access Journals (Sweden)

    Héctor Gómez Santa María

    2009-01-01

    Full Text Available Los primeros registros de embolia pulmonar por polimetilmetacrilato se publicaron recientemente (2003 y desde entonces se describieron no más de 15 casos. Se presenta el caso de un paciente joven a quien dos meses antes de la consulta se le había efectuado una vertebroplastia percutánea con polimetilmetacrilato. Por síntomas pleuríticos se le realizó una radiografía de tórax, que evidenció múltiples imágenes radioopacas en ambos campos pulmonares. La embolia pulmonar por polimetilmetacrilato es una complicación muy poco frecuente de ese procedimiento y un diagnóstico diferencial para tener en cuenta en pacientes con el antecedente y que consulten por dolor precordial o disnea.REV ARGENT CARDIOL 2009;77:129-130.

  7. Análise comparativa entre a refração clínica subjetiva e a automatizada obtida por sensor de frentes de onda

    OpenAIRE

    Freitas,Wilson de; Melo Júnior,Luiz Alberto Soares; Schor,Paulo; Campos,Mauro

    2007-01-01

    OBJETIVO: Avaliar e comparar os resultados obtidos da refração estática clínica com a obtida por sensor de frentes de onda. MÉTODOS: Estudo prospectivo, não seqüencial, de 279 olhos de 147 pacientes. Todos os pacientes foram examinados sob cicloplegia. Primeiro realizamos a refração clínica e a seguir a automatizada por sensor de frentes de onda. Os dados refracionais obtidos foram decompostos para análise vetorial. Foram analisados separadamente os dados de um olho por paciente e dos dois ol...

  8. XPS study of silver, nickel and bimetallic silver-nickel nanoparticles prepared by seed-mediated growth

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, Pilar, E-mail: pilar.prieto@uam.es [Departamento de Fisica Aplicada and Instituto de Ciencia de Materiales ' Nicolas Cabrera' , Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Nistor, Valentin [Departamento de Fisica Aplicada and Instituto de Ciencia de Materiales ' Nicolas Cabrera' , Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Nouneh, Khalid [Institute for Nanomaterials and Nanotechnology (INANOTECH), Moroccan Foundation for Advanced Science, Innovation and Research (MAScIR), ENSET, Av. Armee Royale, 10100, Rabat (Morocco); Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8520 (Japan); Oyama, Munetaka [Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8520 (Japan); Abd-Lefdil, Mohammed [Laboratory of Materials Physics, University Mohammed V-Agdal, Rabat (Morocco); Diaz, Raquel [Departamento de Fisica Aplicada and Instituto de Ciencia de Materiales ' Nicolas Cabrera' , Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer We have prepared Ag, Ni and AgNi NPs by derived seed-mediated growth method. Black-Right-Pointing-Pointer The combined use of optical, structural and chemical characterization techniques allows to determine the presence of core-shell structures. Black-Right-Pointing-Pointer The oxidation states of Ag and Ni at the outer layers of the NPs have been studied by XPS. Black-Right-Pointing-Pointer Ag NPs are purely metallic with a fcc structure. Black-Right-Pointing-Pointer Ni NPs are formed by Ni core-NiO + Ni(OH){sub 2} shell structure. Black-Right-Pointing-Pointer Ag core-NiO + Ni(OH){sub 2} shell structure is determined for AgNi NPs, with oxidized silver atoms at the interface. - Abstract: The chemical structure of silver, nickel and bimetallic silver-nickel nanoparticles, i.e. Ag, Ni and AgNi NPs, with sizes {<=}35 nm, obtained by derived seed-mediated growth method on transparent and conductive indium tin oxide (ITO) substrates, has been studied by a comparative X-ray photoelectron spectroscopy (XPS) analysis of Ag 3d, Ni 2p and O1s core levels in combination with X-ray diffraction and optical absorption spectroscopy in the visible range. XPS indicates that the surface of Ag NPs is not oxidized, while Ni NPs are clearly oxidized to nickel oxide and hydroxide. Absorptions at 384 and 600 nm in Ni optical spectrum are consistent with the presence of nickel in oxidized state; however the presence of metallic Ni 2p signal in Ni XPS spectrum indicates that a metallic nickel core is still present. In the case of bimetallic AgNi NPs, the XPS results are consistent with the presence of metallic silver core surrounded by NiO + Ni(OH){sub 2} shell. XPS spectra also show the presence of Ag{sub 2}O at the interface between the Ag metallic core and the oxidized nickel shell. XRD patterns of AgNi and Ag NPs show the typical fcc structure of metallic silver, confirming the presence of Ag metallic core in AgNi NPs. The surface plasmon

  9. CRIAÇÃO DE EMPRESAS POR MICROEMPREENDEDORES

    Directory of Open Access Journals (Sweden)

    Maria Goreti Boaventura

    2012-06-01

    Full Text Available O número de jovens empreendedores vem aumentando no Brasil, pela difi culdade em conseguir trabalho ou pelo desejo de ter o próprio negócio e não ter patrão. Por necessidade ou por vontade de ter o próprio negócio, os jovens se aventuram cada vez mais na criação de novos negócios. Assim, o objetivo deste trabalho foi verifi car quais as principais motivações para a abertura do negócio, quais as difi culdades encontradas para essa abertura e qual o perfi l empreendedor dos jovens, com idades entre 24 e 37 anos, que abrem empresas no setor de moda, em Belo Horizonte, e cujas empresas tenham sido abertas há no máximo cinco anos. O estudo foi qualitativo, sendo utilizada a entrevista semiestruturada como meio de coleta de dados. A análise dos dados foi feita por meio da análise de conteúdo, após tabulação dos dados coletados nas entrevistas. Posteriormente, com base nos dados analisados, foram feitas as considerações gerais.

  10. Superficial characterization by XP S of silver nanoparticles and their hydrothermal deposit over zircaloy; Caracterizacion superficial por XPS de nanoparticulas de plata y su deposito hidrotermal sobre zircaloy

    Energy Technology Data Exchange (ETDEWEB)

    Contreras R, A.; Gutierrez W, C.; Martinez M, I.; Medina A, A. L., E-mail: aida.contreras@inin.gob.mx [ININ, Departamento de Tecnologia de Materiales, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-10-15

    The analysis technique of X-ray photoelectron spectroscopy (XP S) is sensitive exclusively to the first layers of the solids surface, which allows obtaining information about the chemical, physical and electronic properties of them. The combustible elements of the boiling water nuclear reactors (BWR) are formed by zircaloy pipes that contain in their interior pellets or uranium dioxide. In this work is studied the zircaloy surface, oxidized zircaloy under similar conditions to those of a reactor BWR type and oxidized zircaloy with a hydrothermal deposit of silver nanoparticles and zinc. The silver deposit is a proposal of the Materials Technology Department of the Instituto Nacional de Investigaciones Nucleares (ININ) in Mexico, which has the same objective that the noble metals deposit (Pt, Pd, and Rh) that is practiced in some of the reactors BWR, in order to mitigating the speed of crack growth for IGSCC in stainless steels 304 Ss. (Author)

  11. Raman and XPS characterization of vanadium oxide thin films with temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ureña-Begara, Ferran, E-mail: ferran.urena@uclouvain.be [Université catholique de Louvain, Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Louvain-la-Neuve (Belgium); Crunteanu, Aurelian [XLIM Research Institute, UMR 7252, CNRS/Université de Limoges, Limoges (France); Raskin, Jean-Pierre [Université catholique de Louvain, Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Louvain-la-Neuve (Belgium)

    2017-05-01

    Highlights: • Comprehensive study of the oxidation of VO{sub 2} thin films from R.T. up to 550 °C. • Phase changes and mixed-valence vanadium oxides formed during the oxidation process. • Reported Raman and XPS signatures for each vanadium oxide. • Monitoring of the current and resistance evolution at the surface of the films. • Oxidation model describing the evolution of the vanadium oxides and phase changes. - Abstract: The oxidation mechanisms and the numerous phase transitions undergone by VO{sub 2} thin films deposited on SiO{sub 2}/Si and Al{sub 2}O{sub 3} substrates when heated from room temperature (R.T.) up to 550 °C in air are investigated by Raman and X-ray photoelectron spectroscopy. The results show that the films undergo several intermediate phase transitions between the initial VO{sub 2} monoclinic phase at R.T. and the final V{sub 2}O{sub 5} phase at 550 °C. The information about these intermediate phase transitions is scarce and their identification is important since they are often found during the synthesis of vanadium dioxide films. Significant changes in the film conductivity have also been observed to occur associated to the phase transitions. In this work, current and resistance measurements performed on the surface of the films are implemented in parallel with the Raman measurements to correlate the different phases with the conductivity of the films. A model to explain the oxidation mechanisms and phenomena occurring during the oxidation of the films is proposed. Peak frequencies, full-width half-maxima, binding energies and oxidation states from the Raman and X-ray photoelectron spectroscopy experiments are reported and analyzed for all the phases encountered in VO{sub 2} films prepared on SiO{sub 2}/Si and Al{sub 2}O{sub 3} substrates.

  12. Characterization study of native oxides on GaAs(100) surface by XPS

    Science.gov (United States)

    Feng, Liu; Zhang, Lian-dong; Liu, Hui; Gao, Xiang; Miao, Zhuang; Cheng, Hong-chang; Wang, Long; Niu, Sen

    2013-08-01

    In order to know more about the surface state of GaAs(100) epitaxial wafer during a storage period of two years, the XPS analysis was carried out four times on the surface, respectively polished by chemical etching, stored in desiccator for half a year, one year and two years. The results indicated that even after cleaned by proper etchant solutions, the fresh surface was slightly oxidized with Ga2O3, As2O3 and organic contaminant. The epi-wafer was always exposed to air during the storage period, so more and more oxides turned out. The mixed oxide layer comprised of C-OR, COOR, Ga2O3, As2O3 and As2O5 appeared after only half a year. In the ageing process of two years, the oxide types of gallium or arsenic did not change with stable content of Ga2O3 and remarkably fluctuating relative contents of As2O3 and As2O5. Based on the intensity ratio of Ga 3d-Ga2O3 to Ga 3d-GaAs, the thickness of oxide layer was estimated. The oxide layer generated after chemical polishing was very thin, just only 0.435nm thick, and then it grew rapidly, approximately 1.822nm after one year while almost no change any more subsequently. It was indicated that after the epi-wafer was stored for one year, because of volatile As2O3 or As2O5, there remained a large amount of Ga2O3 in oxide layer, which prevented the reactions between bulk material and oxide layer with oxygen. So native oxide layer plays a role as passive film to protect epi-wafer against the environment during a long storage period.

  13. XPS characterization of sensitized n-TiO{sub 2} thin films for dye-sensitized solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Patrocinio, Antonio Otavio T. [Laboratory of Inorganic Photochemistry and Energy Conversion, Instituto de Quimica, Universidade de Sao Paulo (Brazil); Paniago, Eucler B. [Departamento de Quimica, Universidade Federal de Ouro Preto (Brazil); Paniago, Roberto M. [Departamento de Fisica, Universidade Federal de Minas Gerais (Brazil); Iha, Neyde Y. Murakami [Laboratory of Inorganic Photochemistry and Energy Conversion, Instituto de Quimica, Universidade de Sao Paulo (Brazil)], E-mail: neydeiha@iq.usp.br

    2008-01-15

    TiO{sub 2} thin films, employed in dye-sensitized solar cells, were prepared by the sol-gel method or directly by Degussa P25 oxide and their surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The effect of adsorption of the cis-[Ru(dcbH{sub 2}){sub 2}(NCS){sub 2}] dye, N3, on the surface of films was investigated. From XPS spectra taken before and after argon-ion sputtering procedure, the surface composition of inner and outer layers of sensitized films was obtained and a preferential etching of Ru peak in relation to the Ti and N ones was identified. The photoelectrochemical parameters were also evaluated and rationalized in terms of the morphological characteristics of the films.

  14. The determination of acid-base properties of polymer surfaces by XPS: Present status and future prospects

    International Nuclear Information System (INIS)

    Chehimi, M.M.; Delamar, M.; Shahidzadeh-Ahmadi, N.; Arefi-Khonsari, F.; Amouroux, J.; Watts, J.F.

    1996-01-01

    The use of the molecular probe technique in conjunction with X-ray photoelectron spectroscopy (XPS) for the assessment of acid-base properties of polymer surfaces is reviewed. The method is based on the determination of the concentration and chemical shifts of Lewis acids (bases) sorbed in polymers of basic (acidic) character. In the case of chloroform (Lewis acid) sorbed in polymers of Lewis basic character, C12p binding energy is linearly correlated with ΔH AB , the heat of acid-base complex formation chloroform-polymer. This relationship has been used to determine the acid-base properties of poly(phenylene oxide), a homopolymer, and ammonia plasma-treated polypropylene. This work shows that XPS can now indeed be used to quantitatively assess the acid-base properties of modified polymer surfaces and perhaps be extended to map acid-base properties of polymer surfaces at the micron or submicron scale. copyright 1996 American Institute of Physics

  15. Growth of TiC films by Pulsed Laser Evaporation (PLE) and characterization by XPS and AES

    International Nuclear Information System (INIS)

    Rist, O.; Murray, P.T.

    1991-01-01

    Thin films of TiC with a thickness of some 100 nm have been grown on Si(100) substrates by Pulsed Laser Evaporation (PLE). Advantages of PLE in comparison with more conventional growth methods e.g. PVD or CVD are reported. The feasibility of growing stoichiometric thin films of TiC by PLE was investigated. These films produced have been analysed in situ by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). XPS results and Auger sputter depht profiles indicate that the films grown between RT and 500degC are stoichiometric TiC. Film/substrate interdiffusion is observed at 600degC substrate temperature and higher. (orig.)

  16. Surface and bulk investigation of ZSM5 and Al-MCM-41 usingsynchrotron XPS, XANES, and hexane cracking

    Energy Technology Data Exchange (ETDEWEB)

    Jalil, P.A.; Kariapper, M.S.; Faiz, Z.; Tabet, N.; Hamdan, N.M.; Diaz, J.; Hussain, Z.

    2005-05-12

    We present a comparative study of ZSM5 and Al-MCM-41 catalysts using spectroscopic and chemical techniques. The analysis of conventional and synchrotron XPS spectra of these catalysts reveals the presence of a topmost surface-related Si peak in addition to the bulk peak. XANES results suggest structural modification upon heating Al-MCM-41 at 500 C. Depth-resolved XPS data show Al depletion from the surface of Al-MCM-41 in contrast to surface enrichment of Al in ZSM5. These surface modifications could be one of the reasons for the weak acidity of Al-MCM-41 in chemical reactions such as hexane cracking at different temperatures.

  17. Surface and bulk investigation of ZSM5 and Al-MCM-41 usingsynchrotron XPS, XANES, and hexane cracking

    Energy Technology Data Exchange (ETDEWEB)

    Jalil, P.A.; Kariapper, M.S.; Faiz, Z.; Tabet, N.; Hamdan, N.M.; Diaz, J.; Hussain, Z.

    2005-05-12

    We present a comparative study of ZSM5 and Al-MCM-41 catalysts using spectroscopic and chemical techniques. The analysis of conventional and synchrotron XPS spectra of these catalysts reveals the presence of a topmost surface-related Si peak in addition to the bulkpeak. XANES results suggest structural modification upon heating Al-MCM-41 at 500 C. Depth-resolved XPS data show Al depletion from the surface of Al-MCM-41 in contrast to surface enrichment of Al in ZSM5. These surface modifications could be one of the reasons for the weak acidity of Al-MCM-41 in chemical reactions such as hexane cracking at different temperatures.

  18. A poly-epoxy surface explored by Hartree-Fock ΔSCF simulations of C1s XPS spectra.

    Science.gov (United States)

    Gavrielides, A; Duguet, T; Esvan, J; Lacaze-Dufaure, C; Bagus, P S

    2016-08-21

    Whereas poly-epoxy polymers represent a class of materials with a wide range of applications, the structural disorder makes them difficult to model. In the present work, we use good experimental model samples in the sense that they are pure, fully polymerized, flat and smooth, defect-free, and suitable for ultrahigh vacuum x-ray photoelectron spectroscopy, XPS, experiments. In parallel, we perform Hartree-Fock, HF, calculations of the binding energies, BEs, of the C1s electrons in a model molecule composed of the two constituents of the poly-epoxy sample. These C1s BEs were determined using the HF ΔSCF method, which is known to yield accurate values, especially for the shifts of the BEs, ΔBEs. We demonstrate the benefits of combining rigorous theory with careful XPS measurements in order to obtain correct assignments of the C1s XPS spectra of the polymer sample. Both the relative binding energies-by the ΔSCF method-and relative intensities-in the sudden approximation, SA, are calculated. It results in an excellent match with the experimental spectra. We are able to identify 9 different chemical environments under the C1s peak, where an exclusively experimental work would have found only 3 contributions. In addition, we observe that some contributions are localized at discrete binding energies, whereas others allow a much wider range because of the variation of their second neighbor bound polarization. Therefore, HF-ΔSCF simulations significantly increase the spectral resolution of XPS and thus offer a new avenue for the exploration of the surface of polymers.

  19. X-PEEM, XPS and ToF-SIMS characterisation of xanthate induced chalcopyrite flotation: Effect of pulp potential

    Science.gov (United States)

    Kalegowda, Yogesh; Chan, Yuet-Loy; Wei, Der-Hsin; Harmer, Sarah L.

    2015-05-01

    Synchrotron-based X-ray photoemission electron microscopy (X-PEEM), X-ray photo-electron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and ultraviolet visible spectroscopy were used to characterize the flotation behaviour of chalcopyrite with xanthate at different processing conditions. The flotation recovery of chalcopyrite decreased from 97% under oxidative conditions (Eh ~ 385 mV SHE, pH 4) to 41% at a reductive potential of - 100 mV SHE (at pH 9). X-PEEM images constructed from the metal L3 absorption edges were used to produce near-edge X-ray absorption fine structure (NEXAFS) spectra from regions of interest, allowing the variability in mineral surface chemistry of each mineral particle to be analysed, and the effect of pulp potential (Eh) on the flotation of chalcopyrite to be determined. XPS, ToF-SIMS and NEXAFS analyses of chalcopyrite particles at oxidative conditions show that the surface was mildly oxidised and covered with adsorbed molecular CuEX. The Cu 2p XPS and Cu L2,3 NEXAFS spectra were dominated by CuI species attributed to bulk chalcopyrite and adsorbed CuEX. At a reductive potential of - 100 mV SHE, an increase in concentration of CuI and FeIII oxides and hydroxides was observed. X-PEEM analysis was able to show the presence of a low percentage of CuII oxides (CuO or Cu(OH)2) with predominantly CuI oxide (Cu2O) which is not evident in Cu 2p XPS spectra.

  20. Positive XPS binding energy shift of supported Cu{sub N}-clusters governed by initial state effects

    Energy Technology Data Exchange (ETDEWEB)

    Peters, S.; Peredkov, S. [Technische Universität Berlin, IOAP, Strasse des 17. Juni 135, 10623 Berlin (Germany); Al-Hada, M. [Department of Physics, College of Education and Linguistics, University of Amran (Yemen); Neeb, M., E-mail: matthias.neeb@helmholtz-berlin.de [Helmholtz-Zentrum Berlin, Wilhelm-Conrad-Röntgen-Campus Adlershof, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin (Germany); Eberhardt, W. [Technische Universität Berlin, IOAP, Strasse des 17. Juni 135, 10623 Berlin (Germany); DESY, Center for Free Electron Laser Science (CFEL), Notkestr. 85, 22607 Hamburg (Germany)

    2014-01-01

    Highlights: • Size dependent initial and final state effects of mass-selected deposited clusters. • Initial state effect dominates positive XPS shift in supported Cu-clusters. • Size dependent Coulomb correlation shift in the Auger final state of Cu cluster. • Size-dependent Auger parameter analysis. • Positive XPS shift differs from negative surface core level shift in crystalline copper. - Abstract: An initial state effect is established as origin for the positive 2p core electron binding energy shift found for Cu{sub N}-clusters supported by a thin silica layer of a p-doped Si(1 0 0) wafer. Using the concept of the Auger parameter and taking into account the usually neglected Coulomb correlation shift in the Auger final state (M{sub 4,5}M{sub 4,5}) it is shown that the initial state shift is comparable to the measured XPS shift while the final state relaxation shift contributes only marginally to the binding energy shift. The cluster results differ from the negative surface core-level shift of crystalline copper which has been explained in terms of a final state relaxation effect.

  1. A quantitative model and the experimental evaluation of the liquid fuel layer for the downward flame spread of XPS foam.

    Science.gov (United States)

    Luo, Shengfeng; Xie, Qiyuan; Tang, Xinyi; Qiu, Rong; Yang, Yun

    2017-05-05

    The objective of this work is to investigate the distinctive mechanisms of downward flame spread for XPS foam. It was physically considered as a moving down of narrow pool fire instead of downward surface flame spread for normal solids. A method was developed to quantitatively analyze the accumulated liquid fuel based on the experimental measurement of locations of flame tips and burning rates. The results surprisingly showed that about 80% of the generated hot liquid fuel remained in the pool fire during a certain period. Most of the consumed solid XPS foam didn't really burn away but transformed as the liquid fuel in the downward moving pool fire, which might be an important promotion for the fast fire development. The results also indicated that the dripping propensity of the hot liquid fuel depends on the total amount of the hot liquid accumulated in the pool fire. The leading point of the flame front curve might be the breach of the accumulated hot liquid fuel if it is enough for dripping. Finally, it is suggested that horizontal noncombustible barriers for preventing the accumulation and dripping of liquid fuel are helpful for vertical confining of XPS fire. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Perfil dos desvios de rotulagem de produtos cosméticos analisados no Instituto Nacional de Controle de Qualidade em Saúde entre 2005 e 2009 / Profile of deviations labeling of cosmetics products have been analyzed by the National Institute for Quality Control in Health between 2005 and 2009

    Directory of Open Access Journals (Sweden)

    Priscila da Nobrega Rito

    2014-08-01

    Full Text Available Um dos documentos necessários para registro/notificação dos produtos cosméticos no Brasil é a apresentação dos dizeres de rotulagem das embalagens e folhetos de instru-ção. No Brasil, requisitos obrigatórios para a rotulagem de produtos cosméticos são encontrados na RDC nº 211/2005. O objetivo do trabalho em questão foi detectar os principais desvios de rotulagem nos produtos cosméticos analisados. Foi realizada uma revisão retrospectiva dos processos arquivados no Instituto Nacional de Controle de Qua-lidade em Saúde referentes às análises de produtos cosméticos realizadas no período de janeiro de 2005 a dezembro de 2009, advindas de solicitações de análises: fiscal, de orientação e especial. Foram avaliados todos os parâmetros relacionados aos dizeres de rotulagem. Essa avaliação foi realizada em 120 amostras das 133 que deram entrada para serem analisadas neste período, sendo obtidos apenas 7 (6% resultados satisfató-rios. Dos 79 produtos analisados de Grau de Risco 2, 75 foram reprovados. A literatura científica corrobora os desvios de rotulagem dos produtos cosméticos encontrados neste trabalho. A classificação Risco 2 é dada aos produtos que trazem consigo um risco ine-rente; sendo assim, os desvios detectados podem colocar o consumidor vulnerável a produtos possivelmente desqualificados. ---------------------------------------------------------- One of the documentation required for registration/notification of cosmetics in Brazil is the presentation of the label of packages and brochures of instruction. In Brazil, mandatory requirements for the labeling of cosmetics are found in RDC no. 211/2005. This object of this paper was to detect main deviations labelling of cosmetics products. We performed a retrospective review of cases filed in National Institute for Quality Control in Health regarding the analyses of cosmetics carried out in the period from January 2005 to December 2009, resulting from

  3. How I Do It: GreenLight XPS 180W photoselective vaporization of the prostate.

    Science.gov (United States)

    Elterman, Dean S

    2015-06-01

    The treatments for benign prostate enlargement (BPE), also known as lower urinary tract symptoms secondary to benign prostatic hypertrophy (BPH-LUTS), have evolved significantly over recent years. Where transurethral resection of the prostate (TURP) has been the gold standard surgery for enlarged prostate glands prostates larger than 80-100 grams, the surgical options were an open, simple prostatectomy or perhaps a staged TURP. Both of these surgeries have the potential for bleeding complications, electrolyte abnormalities, and prolonged hospital admissions. Additional demographic and healthcare forces are also at play. Our aging population of men is being increasingly successfully treated for cardiovascular disease. This means more men are on anti-coagulation therapy, many of whom must stay on these drugs to prevent stent clotting or stroke. Hospital resources, especially overnight hospital admissions do add considerable strain to our healthcare systems. Men are also increasingly becoming more savvy consumers when it comes to their health. Many male patients would prefer to take as few medications as possible. Studies of BPH medications in Europe and the United States have shown drug discontinuation rates between 58%-70% at 1 year. Men who are faced with the choice of daily medication for life versus an outpatient procedure will often opt for the latter, which is in keeping with AUA guidelines that still put surgery as a patient choice alongside medications. Being able to offer GreenLight photoselective vaporization (GL-PVP) with the GreenLight XPS 180Watt system addresses all of these concerns. Men with bothersome BPH-LUTS with essentially any sized prostate gland, can be treated as same-day surgery requiring no overnight admission to hospital, while continuing necessary anti-coagulants, with significantly diminished risks of bleeding, erectile dysfunction, TUR-syndrome. Just as there are many ways to perform a TURP, techniques for GL-PVP do vary. The objectives

  4. Formation of carboxy- and amide-terminated alkyl monolayers on silicon(111) investigated by ATR-FTIR, XPS, and X-ray scattering: Construction of photoswitchable surfaces

    DEFF Research Database (Denmark)

    Rück-Braun, Karola; Petersen, Michael Åxman; Michalik, Fabian

    2013-01-01

    -FTIR and XPS studies of the fulgimide samples revealed closely covered amide-terminated SAMs. Reversible photoswitching of the headgroup was read out by applying XPS, ATR-FTIR, and difference absorption spectra in the mid-IR. In XPS, we observed a reversible breathing of the amide/imide C1s and N1s signals......We have prepared high-quality, densely packed, self-assembled monolayers (SAMs) of carboxy-terminated alkyl chains on Si(111). The samples were made by thermal grafting of methyl undec-10-enoate under an inert atmosphere and subsequent cleavage of the ester functionality to disclose the carboxylic...... zigzag-like substitution pattern for the ester- and carboxy-terminated monolayer. Hydrolysis of the remaining H-Si(111) bonds at the surface furnished HO-Si(111) groups according to XPS and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) studies. The amide-terminated alkyl...

  5. Osteomielitis por salmonella

    Directory of Open Access Journals (Sweden)

    Alicia Velázquez Pérez

    2014-08-01

    Full Text Available Se presenta el caso de una paciente femenina de color blanco y dos años de edad, con diagnóstico prenatal de sicklemia, que desde edades tempranas tiene problemas de la enfermedad. Ingresó en esta ocasión por una de las complicaciones infecciosas que ocasiona este padecimiento, una osteomielitis del húmero izquierdo, aislándose el germen en el hemocultivo realizado, una salmonella. Necesitó de tratamiento enérgico y prolongado; se obtuvo un resultado satisfactorio en la evolución de la enfermedad y se sigue sistemáticamente por consulta externa en la actualidad

  6. Apendicitis por Paracoccidioides brasiliensis

    Directory of Open Access Journals (Sweden)

    Ana Beatriz MUÑOZ URRIBARRI

    2006-01-01

    Full Text Available La paracoccidioidomicosis es la micosis más prevalente en Sudamérica. La forma aguda afecta el sistema fagocítico mononuclear de niños y personas inmunocomprometidas. El compromiso gastrointestinal es frecuente y su patogenia implica diseminación hematógena y linfática. La linfadenomegalia abdominal causa obstrucción intestinal y abdomen agudo. En este artículo damos a conocer el caso de un niño con compromiso gastrointestinal por apendicitis. Este es el primer caso reportado de apendicitis por esta patología. (Rev Med Hered 2006;17:58-60.

  7. DERRIDA E BARTHES: POR ENTRE SINGULARIDADES E PLURALIDADES

    Directory of Open Access Journals (Sweden)

    Raquel Campos

    2015-12-01

    Full Text Available Através da homenagem feita por Derrida a Barthes em seu ensaio “As mortes de Roland Barthes”, o artigo pretende traçar os pontos de encontro entre os dois pensadores em meio à pluralidade de suas ideias e na singularidade das mesmas. “Essa singularidade penetrada me alcança de um golpe, me fere ou me assassina e, em princípio, parece olhar diretamente para mim. […] A mim se dirige a singularidade absoluta do outro” (2008, p.275, como afirma Derrida em seu ensaio. Os pontos intransponíveis entre um indivíduo e outro criam as singularidades, ao mesmo tempo em que contribuem, aporeticamente, à pluralidade de caminhos, possibilidades e ideias. O aparente paradoxo entre esses dois pontos e a coexistência de ambos em um mesmo espaço serão analisados, na tentativa de encontrar consonâncias entre dois tão importantes pensadores, distintos, mas que, por vezes, trabalharam em suas respectivas obras com questões similares.

  8. A comparative study of Mg and Pt contacts on semi-insulating GaAs: Electrical and XPS characterization

    International Nuclear Information System (INIS)

    Dubecký, F.; Kindl, D.; Hubík, P.; Mičušík, M.; Dubecký, M.; Boháček, P.; Vanko, G.; Gombia, E.; Nečas, V.; Mudroň, J.

    2017-01-01

    Highlights: • Explored were diodes with full-area low/high work function metal contacts on semi-insulating GaAs (S). • The Mg-S-Mg diode is promising for radiation detectors for its low high-field current. • The XPS analysis of Mg-S interface shows presence of MgO instead of Mg metal. - Abstract: We present a comparative study of the symmetric metal-SI GaAs-metal (M-S-M) diodes with full-area contacts on both device sides, in order to demonstrate the effect of contact metal work function in a straightforward way. We compare the conventional high work function Pt contact versus the less explored low work function Mg contact. The Pt-S-Pt, Mg-S-Mg and mixed Mg-S-Pt structures are characterized by the current-voltage measurements, and individual Pt-S and Mg-S contacts are investigated by the X-ray photoelectron spectroscopy (XPS). The transport measurements of Mg-S-Pt structure show a significant current decrease at low bias while the Mg-S-Mg structure shows saturation current at high voltages more than an order of magnitude lower with respect to the Pt-S-Pt reference. The phenomena observed in Mg-containing samples are explained by the presence of insulating MgO layer at the M-S interface, instead of the elementary Mg, as confirmed by the XPS analysis. Alternative explanations of the influence of MgO layer on the effective resistance of the structures are presented. The reported findings have potential applications in M-S-M sensors and radiation detectors based on SI GaAs.

  9. [Quantitative surface analysis of Pt-Co, Cu-Au and Cu-Ag alloy films by XPS and AES].

    Science.gov (United States)

    Li, Lian-Zhong; Zhuo, Shang-Jun; Shen, Ru-Xiang; Qian, Rong; Gao, Jie

    2013-11-01

    In order to improve the quantitative analysis accuracy of AES, We associated XPS with AES and studied the method to reduce the error of AES quantitative analysis, selected Pt-Co, Cu-Au and Cu-Ag binary alloy thin-films as the samples, used XPS to correct AES quantitative analysis results by changing the auger sensitivity factors to make their quantitative analysis results more similar. Then we verified the accuracy of the quantitative analysis of AES when using the revised sensitivity factors by other samples with different composition ratio, and the results showed that the corrected relative sensitivity factors can reduce the error in quantitative analysis of AES to less than 10%. Peak defining is difficult in the form of the integral spectrum of AES analysis since choosing the starting point and ending point when determining the characteristic auger peak intensity area with great uncertainty, and to make analysis easier, we also processed data in the form of the differential spectrum, made quantitative analysis on the basis of peak to peak height instead of peak area, corrected the relative sensitivity factors, and verified the accuracy of quantitative analysis by the other samples with different composition ratio. The result showed that the analytical error in quantitative analysis of AES reduced to less than 9%. It showed that the accuracy of AES quantitative analysis can be highly improved by the way of associating XPS with AES to correct the auger sensitivity factors since the matrix effects are taken into account. Good consistency was presented, proving the feasibility of this method.

  10. An IR and XPS spectroscopy assessment of the physico-chemical surface properties of alumina–YAG nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Spina, Giulia; Bonelli, Barbara, E-mail: barbara.bonelli@polito.it; Palmero, Paola, E-mail: paola.palmero@polito.it; Montanaro, Laura

    2013-12-16

    Well-dispersed nano-crystalline transition alumina suspensions were mixed with yttrium chloride aqueous solutions, with the aim of producing by spray-drying Al{sub 2}O{sub 3}–Y{sub 3}Al{sub 5}O{sub 12} (YAG) composite powders of increasing YAG vol.%. Two samples were prepared, with different Y content, corresponding to 5 and 20 YAG vol.%, respectively. Both samples were then treated at either 600 or 1150 °C. The obtained powders were characterized by X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infra Red (FT-IR) spectroscopy and compared to three reference samples: commercial nano-crystalline transition alumina, YAG and Y{sub 2}O{sub 3}. YAG powders were obtained by co-precipitation route whereas Y{sub 2}O{sub 3} powders were yielded by spray-drying of a yttrium chloride aqueous solution. Modification of physico-chemical properties of the surface of alumina nanoparticles were assessed by combining XPS and FT-IR spectroscopies. On the basis of the results obtained, a possible model is proposed for the structure of the obtained composites, in which Y basically reacts with more acidic hydroxyls of alumina, by forming Y-rich surface grains, the extension of which depends on the thermal treatment. - Highlights: • Al{sub 2}O{sub 3}–Y{sub 3}Al{sub 5}O{sub 12} (YAG) composite nanopowders were prepared by spray drying. • Combined XPS and IR spectroscopy: effective tools to study surface modifications. • Y reacts with more acidic hydroxyls at alumina surface. • Y-rich surface grains form: their extension depends on the thermal treatment.

  11. Tracking the conversion of nitrogen during pyrolysis of antibiotic mycelial fermentation residues using XPS and TG-FTIR-MS technology

    International Nuclear Information System (INIS)

    3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" data-affiliation=" (Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention - LAP3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" >Zhu, Xiangdong; 3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" data-affiliation=" (Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention - LAP3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" >Yang, Shijun; Wang, Liang; 3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" data-affiliation=" (Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention - LAP3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" >Liu, Yuchen; 3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" data-affiliation=" (Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention - LAP3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" >Qian, Feng; Yao, Wenqing; 3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" data-affiliation=" (Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention - LAP3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" >Zhang, Shicheng; 3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" data-affiliation=" (Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention - LAP3, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China))" >Chen, Jianmin

    2016-01-01

    Antibiotic mycelial fermentation residues (AMFRs), which are emerging solid pollutants, have been recognized as hazardous waste in China since 2008. Nitrogen (N), which is an environmental sensitivity element, is largely retained in AMFR samples derived from fermentation substrates. Pyrolysis is a promising technology for the treatment of solid waste. However, the outcomes of N element during the pyrolysis of AMFRs are still unknown. In this study, the conversion of N element during the pyrolysis of AMFRs was tracked using XPS (X-ray photoelectron spectroscopy) and online TG-FTIR-MS (Thermogravimetry-Fourier transform infrared-Mass spectrometry) technology. In the AMFR sample, organic amine-N, pyrrolic-N, protein-N, pyridinic-N, was the main N-containing species. XPS results indicated that pyrrolic-N and pyridinic-N were retained in the AMFR-derived pyrolysis char. More stable species, such as N-oxide and quaternary-N, were also produced in the char. TG-FTIR-MS results indicated that NH 3 and HCN were the main gaseous species, and their contents were closely related to the contents of amine-N and protein-N, and pyrrolic-N and pyridinic-N of AMFRs, respectively. Increases in heating rate enhanced the amounts of NH 3 and HCN, but had less of an effect on the degradation degree of AMFRs. N-containing organic compounds, including amine-N, nitrile-N and heterocyclic-N, were discerned from the AMFR pyrolysis process. Their release range was extended with increasing of heating rate and carbon content of AMFR sample. This work will help to take appropriate measure to reduce secondary pollution from the treatment of AMFRs. - Highlights: • Hazardous AMFR material was treated by slow pyrolysis reaction. • TG-FTIR-MS were used to study the N conversion for pyrolysis gas and bio-oil. • NH 3 and HCN were observed as the main N-containing gas species. • XPS were used to study the N conversion for pyrolysis char. • Stable species, such as N-oxide and quaternary-N, were

  12. XPS depth profiling of derivatized amine and anhydride plasma polymers: Evidence of limitations of the derivatization approach

    Energy Technology Data Exchange (ETDEWEB)

    Manakhov, Anton, E-mail: ant-manahov@ya.ru [National University of Science and Technology “MISiS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Michlíček, Miroslav [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská, 2, Brno 61137 (Czech Republic); Felten, Alexandre; Pireaux, Jean-Jacques [LISE, Department of Physics, University of Namur, Rue de Bruxelles, 61, Namur B5000 (Belgium); Nečas, David [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Zajíčková, Lenka [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská, 2, Brno 61137 (Czech Republic)

    2017-02-01

    Highlights: • TFBA derivatizatized amine plasma layers exhibited heterogeneous profile of [F] due to low diffusion (permeability) of TFBA • Anhydride layers derivatized by trifluoroethylamine exhibited relatively homogenous profile as this molecule is smaller • The results of TFBA derivatization will depend on XPS take-off angle, polymer crosslinking and density - Abstract: The quantitative analysis of the chemistry at the surface of functional plasma polymers is highly important for the optimization of their deposition conditions and, therefore, for their subsequent applications. The chemical derivatization of amine and carboxyl-anhydride layers is a well-known technique already applied by many researchers, notwithstanding the known drawback of the derivatization procedures like side or uncomplete reactions that could lead to “unreliable” results. In this work, X-ray photoelectron spectroscopy (XPS) combined with depth profiling with argon clusters is applied for the first time to study derivatized amine and carboxyl-anhydride plasma polymer layers. It revealed an additional important parameter affecting the derivatization reliability, namely the permeation of the derivatizing molecule through the target analysed layer, i.e. the composite effect of the probe molecule size and the layer porosity. Amine-rich films prepared by RF low pressure plasma polymerization of cyclopropylamine were derivatized with trifluoromethyl benzaldehide (TFBA) and it was observed by that the XPS-determined NH{sub 2} concentration depth profile is rapidly decreasing over top ten nanometers of the layer. The anhydride-rich films prepared by atmospheric plasma co-polymerization of maleic anhydride and C{sub 2}H{sub 2} have been reacted with, parafluoroaniline and trifluoroethyl amine. The decrease of the F signal in top surface layer of the anhydride films derivatized by the “large” parafluoroaniline was observed similarly as for the amine films but the derivatization with

  13. Investigation of the CANLUB/sheath interface in CANDU fuel at extended burnup by XPS and SEM/WDX

    International Nuclear Information System (INIS)

    Hocking, W.H.; Behnke, R.; Duclos, A.M.; Gerwing, A.F.; Chan, P.K.

    1997-01-01

    A systematic investigation of the fuel-sheath interface in CANDU fuel as a function of extended burnup has been undertaken by XPS and SEM/WDX analysis. Adherent deposits of UO 2 and fission products, including Cs, Ba, Rb, I, Te, Cd and possibly Ru, have been routinely identified on CANLUB coated and bare Zircaloy surfaces. Some trends in the distribution and chemistry of key fission products have begun to emerge. Several potential mechanisms for degradation of the CANLUB graphite layer at high burnup have been practically excluded. New evidence of carbon relocation within the fuel element and limited reaction with excess oxygen has also been obtained. (author)

  14. XPS and GDOES Characterization of Porous Coating Enriched with Copper and Calcium Obtained on Tantalum via Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Krzysztof Rokosz

    2016-01-01

    Full Text Available XPS and GDOES characterizations of porous coatings on tantalum after Plasma Electrolytic Oxidation (PEO at 450 V for 3 minutes in electrolyte containing concentrated (85% phosphoric acid with calcium nitrate and copper (II nitrate are described. Based on the obtained data, it may be concluded that the PEO coating consists of tantalum (Ta5+, calcium (Ca2+, copper (Cu2+  and Cu+, and phosphates (PO43-. It has to be pointed out that copper and calcium are distributed throughout the volume. The authors also propose a new model of PEO, based on the derivative of GDOES signals with sputtering time.

  15. Atomic and Nuclear Analytical Methods XRF, Mössbauer, XPS, NAA and Ion-Beam Spectroscopic Techniques

    CERN Document Server

    Verma, H R

    2007-01-01

    This book is a blend of analytical methods based on the phenomenon of atomic and nuclear physics. It comprises comprehensive presentations about X-ray Fluorescence (XRF), Mössbauer Spectroscopy (MS), X-ray Photoelectron Spectroscopy (XPS), Neutron- Activation Analysis (NAA), Particle Induced X-ray Emission Analysis (PIXE), Rutherford Backscattering Analysis (RBS), Elastic Recoil Detection (ERD), Nuclear Reaction Analysis (NRA), Particle Induced Gamma-ray Emission Analysis (PIGE), and Accelerator Mass Spectrometry (AMS). These techniques are commonly applied in the fields of medicine, biology, environmental studies, archaeology or geology et al. and pursued in major international research laboratories.

  16. Characterization of uranium bioaccumulation on a fungal isolate Geotrichum sp. dwc-1 as investigated by FTIR, TEM and XPS

    International Nuclear Information System (INIS)

    Changsong Zhao; Congcong Ding; Jiali Liao; Jijun Yang; Yuanyou Yang; Jun Tang; Ning Liu; Qun Sun

    2016-01-01

    In this paper, TEM-EDX, FTIR, XPS, PIXE, and EPBS were employed to identify the uranium biosorption behavior and the potential mechanism on cells of Geotrichum sp. dwc-1, isolated from soils. These results displayed that the biosorption behavior was greatly dependent on pH and uranium was absorbed by bounding to amino, phosphate as well as carboxyl functional groups. Uranium biosorption behavior on Geotrichum sp. dwc-1 involves bioaccumulation, electrostatic interaction and ion exchange process. This work throws further light on potential fungal roles these mechanisms for elemental recovery and bioremediation. (author)

  17. An XPS study on the attachment of triethoxsilylbutyraldehyde to two titanium surfaces as a way to bond chitosan

    International Nuclear Information System (INIS)

    Martin, Holly J.; Schulz, Kirk H.; Bumgardner, Joel D.; Walters, Keisha B.

    2008-01-01

    A bioactive coating has the ability to create a strong interface between bone tissue and implant. Chitosan, a biopolymer derived from the exoskeletons of shellfish, exhibits many bioactive properties that make it an ideal material for use as a coating such as antibacterial, biodegradable, non-toxic, and the ability to attract and promote bone cell growth and organized bone formation. A previous study reported on the bonding of chitosan to a titanium surface using a three-step process. In the current study, 86.4% de-acetylated chitosan coatings were bound to implant quality titanium in a two-step process that involved the deposition of triethoxsilylbutyraldehyde (TESBA) in toluene, followed by a reaction between the aldehyde of TESBA with chitosan. The chitosan coatings were examined on two different metal treatments to determine if any major differences in the ability of titanium to bind chitosan could be detected. The surface of the titanium metal and the individual reaction steps were examined using X-ray photoelectron spectroscopy (XPS). Following the deposition of TESBA, significant changes were seen in the amounts of oxygen, silicon, carbon, and titanium present on the titanium surface, which were consistent with the anticipated reaction steps. It was demonstrated that more TESBA was bound to the piranha-treated titanium surface as compared to the passivated titanium surface. The two different silane molecules, aminopropyltriethoxysilane (APTES) and TESBA, did not affect the chemistry of the resultant chitosan films. XPS showed that both the formation of unwanted polysiloxanes and the removal of the reactive terminal groups were prevented by using toluene as the carrier solvent to bond TESBA to the titanium surfaces, instead of an aqueous solvent. Qualitatively, the chitosan films demonstrated improved adhesion after using toluene, as the films remained attached to the titanium surface even when placed under the ultra-high vacuum necessary for XPS, unlike the

  18. XPS study on the surface reaction of uranium metal in H2 and H2-CO atmospheres

    International Nuclear Information System (INIS)

    Wang Xiaolin; Fu Yibei; Xie Renshou

    1996-04-01

    The surface reactions of uranium metal in H 2 and H 2 -CO atmospheres and the effects of temperature and CO on the hydriding reaction have been studied by X-ray photoelectron spectroscopy (XPS). The reaction between commercial H 2 and uranium metal at 25 degree C leads mainly to the further oxidation of surface layer of metal due to traces of water vapour. At 200 degree C, it may lead to the hydriding reaction of uranium and the hydriding increases with increasing the exposure of H 2 . Investigation indicates CO inhibits both the hydriding reaction and oxidation on the condition of H 2 -CO atmospheres. (13 refs., 10 figs.)

  19. Solar Ion Processing of Major Element Surface Compositions of Mature Mare Soils: Insights from Combined XPS and Analytical TEM Observations

    Science.gov (United States)

    Christoffersen, R.; Dukes, C.; Keller, L. P.; Baragiola, R.

    2012-01-01

    Solar wind ions are capable of altering the sur-face chemistry of the lunar regolith by a number of mechanisms including preferential sputtering, radiation-enhanced diffusion and sputter erosion of space weathered surfaces containing pre-existing compositional profiles. We have previously reported in-situ ion irradiation experiments supported by X-ray photoelectron spectroscopy (XPS) and analytical TEM that show how solar ions potentially drive Fe and Ti reduction at the monolayer scale as well as the 10-100 nm depth scale in lunar soils [1]. Here we report experimental data on the effect of ion irradiation on the major element surface composition in a mature mare soil.

  20. A visibilidade dos esportes e jogos por meio da filatelia brasileira

    Directory of Open Access Journals (Sweden)

    Júlio César Penereiro

    2013-12-01

    Full Text Available Este artigo trata da divulgação dos esportes e jogos por meio das imagens impressas nos selos postais. Os selos comemorativos podem ser um poderoso meio de divulgação científica para sensibilizar as sociedades, de um modo geral, sobre a importância das pesquisas científicas que foram realizadas, por exemplo, no campo dos esportes. Foram analisados todos os selos brasileiros emitidos entre 1843 e 2010, separando e classificando aqueles com conotações nos esportes. Apresenta-se uma estatística da distribuição dos selos postais segundo as várias modalidades esportivas e a descrição de alguns deles, além de uma proposta do uso desse rico material no ensino do esporte, e para uma maior divulgação do patrimônio esportivo brasileiro.

  1. Miotoxicidade por organofosforados

    Directory of Open Access Journals (Sweden)

    Cavaliere Maria J.

    1996-01-01

    Full Text Available Os organofosforados são um grupo de compostos químicos amplamente utilizados em agropecuária como inseticidas, ocasionando intoxicações acidentais em animais e humanos, e mesmo sendo utilizados em tentativas de suicídio. A toxicidade desses produtos decorre sobretudo de insuficiência cárdio-respiratória por compromentimento do sistema nervoso autônomo. Sabe-se que alguns destes compostos induzem em animais de experimentação e em humanos, uma miopatia caracterizada por degeneração de células musculares, comprometendo sobretudo a musculatura respiratória. Baseado no fato de que este comprometimento contribui para a piora da função respiratória, propõe-se um protocolo de avaliação rotineira de miotoxicidade por compostos organofosforados, através de uma bateria mínima e suficiente de colorações e reações histoquímicas para quantificação da necrose muscular. Utilizaram-se como modelo experimental, grupos de ratos albinos (Wistar intoxicados com o organofosforado paraoxon, com e sem antídotos (atropina ou pralidoxima. Verificou-se nos grupos tratados com paraoxon e paraoxon mais atropina, necrose de fibras musculares no diafragma, que atingia em determinadas áreas até 15% das fibras. No grupo tratado com paraoxon mais pralidoxima, a necrose foi mínima, evidenciando o papel mioprotetor deste último antídoto.

  2. Por mil devaluados pesos

    Directory of Open Access Journals (Sweden)

    Annie Rodríguez Collázos

    2013-03-01

    Full Text Available El estudio de lo popular y lo urbano hasta ahora se ha centrado en el comportamiento y en algunas relaciones de los habitantes con su entorno. “Por mil devaluados pesos. Publicidad popular y urbana”, pretende explorar las formas de publicidad, dispersas en diferentes espacios populares y urbanos en Bogotá, identificando esquemas y formas características de sus propios códigos comunicativos; se centran en un objeto de estudio consistente en las estrategias publicitarias y los códigos comunicativos en los mensajes publicitarios populares en las subculturas de San Victorino, 7 de Agosto y Sanandresito de San José.

  3. Infecciones por citomegalovirus

    Directory of Open Access Journals (Sweden)

    Ana Gloria Díaz Martínez

    1998-06-01

    Full Text Available Se ofrece una revisión actualizada sobre la infección por citomegalovirus a partir de la consulta de artículos referidos de 1990 a 1996 en las bases de datos MEDLINE, LILACS, Literatura Cubana de Medicina y Noticias de Salud. Se revisaron 37 artículos. Se abordan los aspectos más importantes de las manifestaciones clínicas, el diagnóstico, el tratamiento, así como la prevención y los métodos de control para evitar las enfermedades citomegálicas

  4. Consumo de charque e técnicas de dessalga adotadas por uma população de hipertensos da região nordeste do Brasil

    OpenAIRE

    Vasconcelos,Sandra Mary Lima; Vieira,Evla Darc Ferro; Chagas,Nidyanne Patrícia Mesquita; Silva,Patricia Maria Candido; Santos,Tatiana Maria Palmeira dos

    2010-01-01

    ObjetivoDescrever o impacto de técnicas de dessalga sobre o teor de sal no charque consumido por hipertensos nordestinos.MétodosEstudo transversal com 404 hipertensos. Mediante consentimento, aplicou-se questionário sobre frequência, quantidade consumida e técnicas de dessalga do charque empregadas pela população. Por meio da "técnica de determinação de cloretos", foi analisado o impacto das técnicas mais citadas sobre o teor de sal no alimento e comparadas àquela considerada padrão neste est...

  5. The influence of oxygen adsorption on the NEXAFS and core-level XPS spectra of the C60 derivative PCBM

    International Nuclear Information System (INIS)

    Brumboiu, Iulia Emilia; Eriksson, Olle; Brena, Barbara; Ericsson, Leif; Hansson, Rickard; Moons, Ellen

    2015-01-01

    Fullerenes have been a main focus of scientific research since their discovery due to the interesting possible applications in various fields like organic photovoltaics (OPVs). In particular, the derivative [6,6]-phenyl-C 60 -butyric acid methyl ester (PCBM) is currently one of the most popular choices due to its higher solubility in organic solvents compared to unsubstituted C 60 . One of the central issues in the field of OPVs is device stability, since modules undergo deterioration (losses in efficiency, open circuit voltage, and short circuit current) during operation. In the case of fullerenes, several possibilities have been proposed, including dimerization, oxidation, and impurity related deterioration. We have studied by means of density functional theory the possibility of oxygen adsorption on the C 60 molecular moiety of PCBM. The aim is to provide guidelines for near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) measurements which can probe the presence of atomic or molecular oxygen on the fullerene cage. By analysing several configurations of PCBM with one or more adsorbed oxygen atoms, we show that a joint core level XPS and O1s NEXAFS investigation could be effectively used not only to confirm oxygen adsorption but also to pinpoint the bonding configuration and the nature of the adsorbate

  6. Surface modification of pyrolyzed carbon fibres by cyclic voltammetry and their characterization with XPS and dye adsorption

    International Nuclear Information System (INIS)

    Georgiou, P.; Walton, J.; Simitzis, J.

    2010-01-01

    Commercial carbon fibres were pyrolyzed up to 1000 deg. C and were then electrochemically treated by cyclic voltammetry in aqueous electrolyte solutions of H 2 SO 4 , in two potential sweep ranges: a narrow region, N, and a wide region, W, avoiding and including water decomposition, respectively. The anodic and cathodic peaks were correlated with oxide formation and their partial reduction, respectively. The nature of oxygen containing groups on the fibre surfaces was determined by XPS. Wide scan spectra and high energy resolution spectra were recorded through the C 1s, O 1s, N 1s and S 2p photoelectron regions. The ability of the fibres to adsorb methylene blue and alizarin yellow dyes from their aqueous solutions indicates the presence of electron acceptor or donor groups on the fibres, respectively. The carbon fibres were classified into two categories. The first includes electrochemically untreated and treated in the N region, and the second those treated in the W region. The high oxygen concentration and effective dye adsorption on the carbon fibres in the second category indicates that their surfaces were effectively modified. The adsorption of dyes on carbon fibres constitutes a complementary method to XPS for an indirect estimation of oxygen and other groups present on the carbon fibre surfaces.

  7. Influence of oxygen incorporation on the defect structure of GaN microrods and nanowires. An XPS and CL study

    International Nuclear Information System (INIS)

    Guzmán, G; Herrera, M; Silva, R; Vásquez, G C; Maestre, D

    2016-01-01

    We report a cathodoluminescence (CL) and x-ray photoelectron spectroscopy (XPS) study of the influence of oxygen incorporation on the defect structure of GaN microrods and nanowires. The micro- and nanostructures were synthesized by a thermal evaporation method, which enables us to incorporate oxygen at different concentrations by varying the growth temperature. HR-TEM measurements revealed that oxygen generates stacking fault defects and edge dislocations along the GaN nanowires. Amorphous GaO x N y compounds were segregated on the surface of the nanowires. XPS, XRD and CL measurements suggests that the microrods and nanowires were composed of amorphous oxynitride compounds at their surface and GaN at their inner region. CL measurements revealed that the nanostructures generated an emission of 2.68 eV that increased in intensity proportionally to their oxygen content. We have attributed this emission to electronic transitions between donor substitutional-oxygen (O N ) and acceptor interstitial-oxygen (O i ) state levels. (paper)

  8. XPS/NEXAFS spectroscopic and conductance studies of glycine on AlGaN/GaN transistor devices

    Science.gov (United States)

    Myers, Matthew; Khir, Farah Liyana Muhammad; Home, Michael A.; Mennell, Christopher; Gillbanks, Jeremy; Tadich, Anton; Baker, Murray V.; Nener, Brett D.; Parish, Giacinta

    2018-03-01

    We report on a study using a combination of XPS/NEXAFS and conductivity measurements to develop a fundamental understanding of how dipolar molecules interact with the heterostructure device surface and affect the device conductivity of AlGaN/GaN heterostructure-based transistors. In such structures, which are increasingly being investigated for chemical and biological sensing, a 2-dimensional electron gas spontaneously forms at the layer interface that is sensitive to the charge characteristics of the exposed surface. Glycine, chosen for this study because it is the simplest of the amino acids and is known to form a zwitterionic configuration when stabilized through intermolecular interactions, was evaporated under ultra-high vacuum conditions onto the device surface and subsequently both XPS/NEXAFS and conductivity measurements were conducted. NEXAFS spectra show a preferential orientation for the Glycine molecules on the surface and evidence for both neutral and zwitterionic species on the surface. In situ conductivity measurements suggest that the negatively charged carboxylate group is closest to the surface. These results are a unique and pivotal contribution to the previous and at times conflicting literature on the zwitterionic nature of Glycine.

  9. A Novel Approach for the Treatment of Radiation-Induced Hemorrhagic Cystitis with the GreenLight™ XPS Laser

    Directory of Open Access Journals (Sweden)

    Daniel Roberto Martinez

    2015-06-01

    Full Text Available ABSTRACTIntroduction:The treatment of pelvic malignancies with radiotherapy can develop severe sequelae, especially radiation-induced hemorrhagic cystitis. It is a progressive disease that can lead to the need for blood transfusion, hospitalizations, and surgical interventions. This tends to affect the quality of life of these patients, and management can at times be difficult. We have evaluated the GreenLight Xcelerated Performance System (XPS with TruCoag, although primarily used for management of benign prostatic hypertrophy (BPH, for the treatment of radiation-induced hemorrhagic cystitis.Materials and Methods:After International Review Board (IRB approval, a retrospective chart review was performed in addition to a literature search. A series of four male patients, mean age of 81 years, with radiation-induced hemorrhagic cystitis secondary to radiotherapy for pelvic malignancies (3 prostate cancer, 1 rectal cancer were successfully treated with the GreenLight laser after unsuccessful treatment with current therapies described in the literature.Results:All four patients treated with the GreenLight laser had resolution of their hematuria after one treatment and were discharge from the hospital with clear urine.Conclusion:The GreenLight XPS laser shows promising results for the treatment of patients with radiation-induced hemorrhagic cystitis, and deserves further evaluation and validation, especially since there is limited data available in the literature regarding the use of this technology for the treatment of this devastating condition.

  10. XPS\\KOUADIO KOUASSI.xps

    African Journals Online (AJOL)

    HP Pro 2000

    éclaircie dans les impénétrables régénérations de chêne. Dans la forêt tropicale guyanaise, Guitet et al. (2009) ont montré que l'application mixte des éclaircies sélective et systématique a permis une forte croissance en diamètre des tiges des ...

  11. Avaliação da qualidade dos registros de enfermagem no prontuário por meio da auditoria

    OpenAIRE

    Setz,Vanessa Grespan; D'Innocenzo,Maria

    2009-01-01

    OBJETIVO: Desse modo o objetivo deste estudo foi avaliar por meio da auditoria, a qualidade dos registros de enfermagem nos prontuários de pacientes atendidos em unidades de um hospital universitário do município de São Paulo. MÉTODOS: O estudo é descritivo, retrospectivo e o método foi pesquisa documental. Dos 424 prontuários analisados entre novembro de 2006 a janeiro de 2007, em diferentes unidades clinicas e cirúrgicas de um hospital universitário, 43,9% se referiam a óbitos e 56,1% a alt...

  12. Variabilidade genética de populações naturais de caroá por meio de marcadores RAPD

    OpenAIRE

    Silveira,Daniela Garcia; Amorim,Edson Perito; Jesus,Onildo Nunes de; Souza,Fernanda Vidigal Duarte; Pestana,Kátia Nogueira; Santos,Vânia Jesus dos; Santana,José Raniere Ferreira de

    2009-01-01

    O objetivo deste trabalho foi quantificar a variabilidade genética entre e dentro de populações de caroá (Neoglaziovia variegata), por meio de marcadores "random amplified polymorphic DNA" (RAPD). Foram analisados 180 genótipos de caroá, provenientes dos municípios de Guanambi, Juazeiro e Valente, no Estado da Bahia. Foi observado elevado polimorfismo entre as populações de caroá. As dissimilaridades genéticas entre os genótipos variaram de 0,08 a 0,95, com média de 0,44.Avariância molecular ...

  13. Pasos por la salud

    OpenAIRE

    Fierro Rojas, Carlos

    2013-01-01

    Pasos por la Salud surge como un proyecto (mismo que derivara una estrategia de atención) que establece el Departamento de Educación Física Valle de México, para fortalecer la aplicación del programa de Educación Física en Educación Básica, fomentará la práctica del ejercicio físico hacia la promoción de la salud, brindará a los alumnos elementos teóricos y bases metodológicas que le ayuden a comprender los beneficios de salud que producen la práctica del ejercicio, concientizar al alumno de ...

  14. Sepsis por shigella flexneri

    Directory of Open Access Journals (Sweden)

    César Cabrera C

    2005-04-01

    Full Text Available Se presenta un caso raro de sepsis por Shigella flexneri en una paciente de 45 años de edad quien estando hospitalizada para el estudio de un tumor cerebral, requirió el uso de manitol y dosis altas de corticoides; luego de ello presenta deposiciones líquidas con moco y sangre, desarrolla síndrome de respuesta inflamatoria sistémica, luego se aísla Shigella flexneri en el hemocultivo; recibió tratamiento antibiótico con ciprofloxacina. Se describen las características del caso y se comenta de acuerdo con la revisión de literatura.

  15. Por uma arquitetura engajada

    Directory of Open Access Journals (Sweden)

    Maria Encarnação Beltrão Spósito

    2010-01-01

    Full Text Available A Arquitetura é vista, neste texto, como uma possibilidade de se compreender o mundo contemporâneo e, sobretudo, de repensá-lo, se queremos contribuir para a construção de um futuro com maior equidade, nele incluído o respeito às diferenças. Nessa perspectiva, uma Arquitetura engajada teria que considerar sempre o Urbanismo, no sentido de compreender a cidade, como nível de determinação do movimento da Sociedade e não apenas como um cenário em que múltiplas linguagens se expressem. Por seu caráter de ensaio, o texto tem mais o papel de levantar questões e estimular o debate, do que apresentar resultados ou respostas.

  16. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    International Nuclear Information System (INIS)

    Nelson, O.D.; Keller, G.M.

    1997-01-01

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage

  17. Aspectos ultraestruturais de hemócitos de Biomphalaria glabrata Say (1818 (Gastropoda: Planorbidae analisados sob microscopia eletrônica de transmissão Ultrastructural aspects of hemocytes from Biomphalaria glabrata Say (1818 (Gastropoda: Planorbidae analysed with transmission eletronic microscopy

    Directory of Open Access Journals (Sweden)

    Marco Antonio Vasconcelos Santos

    2009-09-01

    Full Text Available Os hemócitos do caramujo Biomphalaria glabrata, um importante transmissor do trematódeo Schistosoma mansoni no Brasil, foram coletados de especimens na região Bragantina, localizada a oeste do estado do Pará. Os hemócitos foram examinados por meio de microscopia eletrônica de transmissão. As células foram fixadas pelo método de rotina com o uso do tampão PHEM (PIPES, HEPES, EGTA e Magnésio. Foram descritos os aspectos ultra-estruturais celulares como inclusões citoplasmáticas limitadas por membranas, mitocôndrias, retículos endoplasmáticos e outros. As observações mostram que esse tampão possui a propriedade de preservação do citoesqueleto celular, apresentando bons resultados na preservação das estruturas dos hemócitos e suas organelas.The blood cells of the pulmonate snail Biomphalaria glabrata from the region of Bragantina in the state of Pará, an important vector of the trematode Schistosoma mansoni in Brazil, were collected and fixed by routine method with PHEM buffer and examined with transmission electron microscopy. Ultrastructural cellular aspects like cytoplasmic inclusions, mitochondrion, vesicles and others organelles are described. The buffer used resulted in good preservations of the hemocytes and their organelles.

  18. Structural and XPS studies of PSi/TiO{sub 2} nanocomposites prepared by ALD and Ag-assisted chemical etching

    Energy Technology Data Exchange (ETDEWEB)

    Iatsunskyi, Igor, E-mail: yatsunskiy@gmail.com [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska Str., 61-614 Poznan (Poland); Kempiński, Mateusz [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska Str., 61-614 Poznan (Poland); Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 (Poland); Nowaczyk, Grzegorz; Jancelewicz, Mariusz [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska Str., 61-614 Poznan (Poland); Pavlenko, Mykola [Department of Experimental Physics, Odessa National I.I. Mechnikov University, 42, Pastera Str., 65023 Odessa (Ukraine); Załęski, Karol [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska Str., 61-614 Poznan (Poland); Jurga, Stefan [NanoBioMedical Centre, Adam Mickiewicz University, 85 Umultowska Str., 61-614 Poznan (Poland); Department of Macromolecular Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)

    2015-08-30

    Highlights: • Porous silicon/TiO{sub 2} nanocomposites have been investigated. • Morphology and chemical composition of PSi/TiO{sub 2} nanocomposites were established. • Valence-band XPS maximums for PSi/TiO{sub 2} nanocomposites were found and analyzed. - Abstract: PSi/TiO{sub 2} nanocomposites fabricated by atomic layer deposition (ALD) and metal-assisted chemical etching (MACE) were investigated. The morphology and phase structure of PSi/TiO{sub 2} nanocomposites were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) with an energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy. The mean size of TiO{sub 2} nanocrystals was determined by TEM and Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical elemental composition by observing the behavior of the Ti 2p, O 1s and Si 2p lines. TEM, Raman spectroscopy and XPS binding energy analysis confirmed the formation of TiO{sub 2} anatase phase inside the PSi matrix. The XPS valence band analysis was performed in order to investigate the modification of PSi/TiO{sub 2} nanocomposites electronic structure. Surface defects states of Ti{sup 3+} at PSi/TiO{sub 2} nanocomposites were identified by analyzing of XPS valence band spectra.

  19. Quantitative analysis of Fe and Co in Co-substituted magnetite using XPS: The application of non-linear least squares fitting (NLLSF)

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hongmei, E-mail: hmliu@gig.ac.cn [CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640 (China); Wei, Gaoling [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, 510650 (China); Xu, Zhen [School of Materials Science and Engineering, Central South University, Changsha, 410012 (China); Liu, Peng; Li, Ying [CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China)

    2016-12-15

    Highlights: • XPS and Auger peak overlapping complicates Co-substituted magnetite quantification. • Disrurbance of Auger peaks was eliminated by non-linear least squares fitting. • Fitting greatly improved the accuracy of quantification for Co and Fe. • Catalytic activity of magnetite was enhanced with the increase of Co substitution. - Abstract: Quantitative analysis of Co and Fe using X-ray photoelectron spectroscopy (XPS) is of important for the evaluation of the catalytic ability of Co-substituted magnetite. However, the overlap of XPS peaks and Auger peaks for Co and Fe complicate quantification. In this study, non-linear least squares fitting (NLLSF) was used to calculate the relative Co and Fe contents of a series of synthesized Co-substituted magnetite samples with different Co doping levels. NLLSF separated the XPS peaks of Co 2p and Fe 2p from the Auger peaks of Fe and Co, respectively. Compared with a control group without fitting, the accuracy of quantification of Co and Fe was greatly improved after elimination by NLLSF of the disturbance of Auger peaks. A catalysis study confirmed that the catalytic activity of magnetite was enhanced with the increase of Co substitution. This study confirms the effectiveness and accuracy of the NLLSF method in XPS quantitative calculation of Fe and Co coexisting in a material.

  20. Quantitative analysis of Fe and Co in Co-substituted magnetite using XPS: The application of non-linear least squares fitting (NLLSF)

    International Nuclear Information System (INIS)

    Liu, Hongmei; Wei, Gaoling; Xu, Zhen; Liu, Peng; Li, Ying

    2016-01-01

    Highlights: • XPS and Auger peak overlapping complicates Co-substituted magnetite quantification. • Disrurbance of Auger peaks was eliminated by non-linear least squares fitting. • Fitting greatly improved the accuracy of quantification for Co and Fe. • Catalytic activity of magnetite was enhanced with the increase of Co substitution. - Abstract: Quantitative analysis of Co and Fe using X-ray photoelectron spectroscopy (XPS) is of important for the evaluation of the catalytic ability of Co-substituted magnetite. However, the overlap of XPS peaks and Auger peaks for Co and Fe complicate quantification. In this study, non-linear least squares fitting (NLLSF) was used to calculate the relative Co and Fe contents of a series of synthesized Co-substituted magnetite samples with different Co doping levels. NLLSF separated the XPS peaks of Co 2p and Fe 2p from the Auger peaks of Fe and Co, respectively. Compared with a control group without fitting, the accuracy of quantification of Co and Fe was greatly improved after elimination by NLLSF of the disturbance of Auger peaks. A catalysis study confirmed that the catalytic activity of magnetite was enhanced with the increase of Co substitution. This study confirms the effectiveness and accuracy of the NLLSF method in XPS quantitative calculation of Fe and Co coexisting in a material.

  1. Control Multivariable por Desacoplo

    Directory of Open Access Journals (Sweden)

    Fernando Morilla

    2013-01-01

    Full Text Available Resumen: La interacción entre variables es una característica inherente de los procesos multivariables, que dificulta su operación y el diseño de sus sistemas de control. Bajo el paradigma de Control por desacoplo se agrupan un conjunto de metodologías, que tradicionalmente han estado orientadas a eliminar o reducir la interacción, y que recientemente algunos investigadores han reorientado con objetivos de solucionar un problema tan complejo como es el control multivariable. Parte del material descrito en este artículo es bien conocido en el campo del control de procesos, pero la mayor parte de él son resultados de varios años de investigación de los autores en los que han primado la generalización del problema, la búsqueda de soluciones de fácil implementación y la combinación de bloques elementales de control PID. Esta conjunción de intereses provoca que no siempre se pueda conseguir un desacoplo perfecto, pero que sí se pueda conseguir una considerable reducción de la interacción en el nivel básico de la pirámide de control, en beneficio de otros sistemas de control que ocupan niveles jerárquicos superiores. El artículo resume todos los aspectos básicos del Control por desacoplo y su aplicación a dos procesos representativos: una planta experimental de cuatro tanques acoplados y un modelo 4×4 de un sistema experimental de calefacción, ventilación y aire acondicionado. Abstract: The interaction between variables is inherent in multivariable processes and this fact may complicate their operation and control system design. Under the paradigm of decoupling control, several methodologies that traditionally have been addressed to cancel or reduce the interactions are gathered. Recently, this approach has been reoriented by several researchers with the aim to solve such a complex problem as the multivariable control. Parts of the material in this work are well known in the process control field; however, most of them are

  2. Structural and electronic analysis of Hf on Si(1 1 1) surface studied by XPS, LEED and XPD

    Energy Technology Data Exchange (ETDEWEB)

    Carazzolle, M.F. [Experimentelle Physik 1, Universitaet Dortmund, Otto-Hahn-Str. 4, D44221 Dortmund (Germany); Instituto de Fisica, Universidade Estadual de Campinas, C.P. 6165, 13083-970 Campinas, SP (Brazil)], E-mail: mcarazzo@ifi.unicamp.br; Schuermann, M.; Fluechter, C.R.; Weier, D. [Experimentelle Physik 1, Universitaet Dortmund, Otto-Hahn-Str. 4, D44221 Dortmund (Germany); Berges, U. [Experimentelle Physik 1, Universitaet Dortmund, Otto-Hahn-Str. 4, D44221 Dortmund (Germany); DELTA, Universitaet Dortmund, Maria-Goeppert-Mayer-Str. 2, D44227 Dortmund (Germany); Siervo, A. de [Laboratorio Nacional de Luz Sincrotron, C.P. 6192, 13084-971 Campinas, SP (Brazil); Landers, R. [Instituto de Fisica, Universidade Estadual de Campinas, C.P. 6165, 13083-970 Campinas, SP (Brazil); Laboratorio Nacional de Luz Sincrotron, C.P. 6192, 13084-971 Campinas, SP (Brazil); Kleiman, G.G. [Instituto de Fisica, Universidade Estadual de Campinas, C.P. 6165, 13083-970 Campinas, SP (Brazil); Westphal, C. [Experimentelle Physik 1, Universitaet Dortmund, Otto-Hahn-Str. 4, D44221 Dortmund (Germany); DELTA, Universitaet Dortmund, Maria-Goeppert-Mayer-Str. 2, D44227 Dortmund (Germany)

    2007-05-15

    In this work, we present a systematic electronic and structural study of the Hf-silicide formation upon annealing on Si(1 1 1) surface. The electronic structure and surface composition were determined by X-ray photoelectron spectroscopy (XPS) and angle-resolved X-ray photoelectron spectroscopy (ARXPS). To determine the atomic structure of the surface alloy we used low energy electron diffraction (LEED) and angle-resolved photoelectron diffraction (XPD). It was possible to verify that, after 600 deg. C annealing, there is alloy formation and after 700 deg. C the Hf diffusion process is predominant. Using LEED and XPD measurements we detected the ordered island formation simultaneously with alloy formation.

  3. The 4s- and 4p- XPS spectra of Xe, XeF2 and XeF4

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2003-01-01

    The 4s- and 4p- XPS spectra of Xe gas, XeF 2 molecule and XeF 4 molecule are calculated by an ab-initio atomic many-body theory. The 4s-peak and the prominent '4p'-peak are predicted well by the present theory. In XeF 2 and XeF 4 the spectral lines observed below the 4d-double ionization threshold are the 4d -2 4f multiplet states strongly perturbed by the interaction with the initial 4p 1/2 -hole state. They are very similar to the spectral lines which emerge with an increase in atomic number (e.g. Ba)

  4. XPS, XAES, and TG/DTA characterization of deposited carbon in methane dehydroaromatization over Ga Mo/ZSM-5 catalyst

    Science.gov (United States)

    Liu, B. S.; Jiang, L.; Sun, H.; Au, C. T.

    2007-03-01

    The catalytic dehydroaromatization of methane over 3.0%Mo/HZSM-5 and 0.1%Ga-3%Mo/HZSM-5 catalysts were reported. The nature of deposited carbon was characterized by means of XPS, XAES, TG/DTG, HRTEM, and DTA techniques. In XAES study, the type of deposited carbon was characterized based on the fine structures of d N/d E spectra. The results confirm that the sp 2/sp 3 bonding ratio of coke species increases with on-stream time, suggesting that the deposition of heavier aromatic-type carbon is the main reason for catalyst deactivation. The addition of gallium to 3.0%Mo/HZSM-5 enhances the adsorption of CO x species as well as the formation of alkene (such as ethylene). Therefore, the Ga-modified 3%Mo/HZSM-5 catalyst is more active and stable than the unmodified one.

  5. Spectroscopic characterization of iron ores formed in different geological environments using FTIR, XPS, Mössbauer spectroscopy and thermoanalyses.

    Science.gov (United States)

    Salama, Walid; El Aref, Mourtada; Gaupp, Reinhard

    2015-02-05

    Application of thermoanalyses, FTIR, XPS and Mössbauer spectroscopic methods can differentiate between iron ores formed in different geological environments. Two types of iron ore are formed in shallow marine environments in the Bahariya Depression, Egypt, yellowish brown ooidal ironstones (type 1) and black mud and fossiliferous ironstones (type 2). Both types were subjected to subaerial weathering, producing a dark brown lateritic (pedogenic) iron ore (type 3). Microscopic investigation indicates goethite is the main mineral in types 1 and 3, while hematite is the main mineral in type 2 and also occurs in type 3. Thermoanalyses indicated the dehydroxylation endothermic peak of goethite of type 1 occurs between 329 and 345°C, while in type 3 occurs between 284 and 330°C. This variation can be attributed to the nanocrystalline nature of the pedogenic goethite. The presence of an exothermic peak at 754°C in type 3 is probably attributed to goethite-hematite phase transformation. FTIR spectroscopy indicated that goethite of type 1 is characterized by the presence of the δ-OH band between 799 and 802cm(-1), the γ-OH between 898 and 904cm(-1) and the bulk hydroxyl stretch between 3124 and 3133cm(-1). Goethite of type 3 is characterized by the absence of the bulk hydroxyl stretch band and the δ-OH and γ-OH are shifted to higher Wavenumbers that can attributed to a relative Al-for Fe-substitution. Hematite is identified by two IR bands; the first is between 464 and 475cm(-1) and at the second is between 540 and 557cm(-1). Quartz is identified in all iron ore types, nitrates are identified in types 1 and 2, but absent in type 3 and Kaolinite is identified in type 2. The Mössbauer spectrum of type 1 is fitted with one magnetic sextet corresponding to goethite with an isomer shift (IS)=0.374mms(-1), a quadruple splitting (QS)=-0.27mms(-1) and a hyperfine magnetic field (BHF)=∼37. The Mössbauer spectrum of type 2 is fitted with one magnetic sextet corresponding

  6. Corrosion and inhibition of copper in hydrocarbon solution on a molecular level investigated using neutron reflectometry and XPS

    International Nuclear Information System (INIS)

    Welbourn, Rebecca J.L.; Truscott, C.L.; Skoda, M.W. A.; Zarbakhsh, A.; Clarke, S.M.

    2017-01-01

    Highlights: • Corrosion of CuO by sulphur in oil is inhibited by organic amine but not thiol. • Neutron reflection gives insight into the layer structure and composition. • The most well packed organic layer does not give the best corrosion protection. • Organic thiol selectively removes Cu(II) to leave a Cu(I) surface. - Abstract: The behaviour and molecular structure of three organic additives adsorbed from oil onto a copper surface rich in copper (II) oxide is presented. The variation in the ability of these three agents to prevent corrosion of the copper oxide surface by exposure to sulphur is also included. A combination of visible observations, X-ray photoelectron spectroscopy (XPS) and neutron reflection (NR) are used to characterise both the adsorbed layer and underlying copper oxide. The model additives are chosen to represent ‘effective’, ‘intermediate’ and ‘ineffective’ inhibitors for copper.

  7. [XPS and Raman spectral analysis of nitrogenated tetrahedral amorphous carbon (ta-C : N) films with different nitrogen content].

    Science.gov (United States)

    Chen, Wang-Shou; Zhu, Jia-Qi; Han, Jie-Cai; Tian, Gui; Tan, Man-Lin

    2009-01-01

    Nitrogenated tetrahedral amorphous carbon (ta-C : N) films were prepared on the polished C--Si substrates by introducing highly pure nitrogen gas into the cathode region and the depositing chamber synchronously using filtered cathodic vacuum arc (FCVA) technology. The nitrogen content in the films was controlled by changing the flow rate of nitrogen gas. The configuration of ta-C : N films was investigated by means of X-ray photoelectron spectroscopy (XPS) and visible Raman spectroscopy. It was shown that the nitrogen content in the films increased from 0.84 at% to 5.37 at% monotonously when the nitrogen flow rate was varied from 2 seem to 20 sccm. The peak position of C (1s) core level moved towards higher binding energy with the increase in nitrogen content. The shift of C (1s) peak position could be ascribed to the chemical bonding between carbon and nitrogen atoms even though more three-fold coordinated sp2 configuration as in graphite was formed when the films were doped with more nitrogen atoms. Additionally, the half width of C(1s) peak gradually was also broadened with increasing nitrogen content. In order to discover clearly the changing regularities of the microstructure of the films, the XPS C(1s) spectra and Raman spectra were deconvoluted using a Gaussian-Lorentzian mixed lineshape. It was shown that the tetrahedral hybridization component was still dominant even though the ratio of sp2/sp3 obtained from C(1s) spectra rose with the increase in nitrogen content. The Raman measurements demonstrated that the G peak position shifted towards higher frequency from 1,561 to 1,578 cm(-1) and the ratio of ID/IG also rose with the increase in nitrogen content. Both results indicated that the graphitizing tendency could occur with the increase in nitrogen content in the films.

  8. XPS, SIMS and FTIR-ATR characterization of boronized graphite from the thermonuclear plasma device RFX-mod

    International Nuclear Information System (INIS)

    Ghezzi, F.; Laguardia, L.; Caniello, R.; Canton, A.; Dal Bello, S.; Rais, B.; Anderle, M.

    2015-01-01

    Highlights: • XPS, ATR and SIMS characterization of samples from the first wall of RFX-mod device. • Amorphous hydrogenated boron carbide plus other carbon type bonds. • Results suggest to increase the number of electrode used for boronization. - Abstract: In this paper the characterization of a thin (tens of nanometers) boron layer on fine grain polycrystalline graphite substrate is presented. The boron film is used as conditioning technique for the full graphite wall of the Reversed Field eXperiment–modified (RFX-mod) experiment, a device for the magnetic confinement of plasmas of thermonuclear interest. Aim of the present analysis is to enlighten the chemical structure of the film, the trapping mechanism that makes it a getter for oxygen and hydrogen and the reason of its loss of effectiveness after exposure to about 100 s of hydrogen plasma. X-ray Photoelectron Spectroscopy (XPS), Secondary Ions Mass Spectrometry (SIMS) and Fourier Transform Infra Red spectroscopy in combination with the Attenuated Total Reflectance (FTIR-ATR) were used to obtain the structure and the chemical composition of graphitic samples as coated or coated and subsequently exposed to hydrogen plasma after boron deposition. The boron layers on the only coated samples were found to be amorphous hydrogenated boron carbide plus a variety of bonds like B-B, B-H, B-O, B-OH, C-C, C-H, C-O, C-OH. Both the thickness and the homogeneity of the layers were found to depend on the distance of the sample from the anode during the deposition. The samples contained oxygen along the layer thickness, at level of 5%, bound to boron. The gettering action of the boron is therefore already active during the deposition itself. The exposure to plasma caused erosion of the boron film and higher content of H and O bound to boron throughout the whole thickness. The interaction of the B layer with plasma is therefore a bulk phenomenon.

  9. Angle-resolved XPS analysis and characterization of monolayer and multilayer silane films for DNA coupling to silica.

    Science.gov (United States)

    Shircliff, Rebecca A; Stradins, Paul; Moutinho, Helio; Fennell, John; Ghirardi, Maria L; Cowley, Scott W; Branz, Howard M; Martin, Ina T

    2013-03-26

    We measure silane density and Sulfo-EMCS cross-linker coupling efficiency on aminosilane films by high-resolution X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. We then characterize DNA immobilization and hybridization on these films by (32)P-radiometry. We find that the silane film structure controls the efficiency of the subsequent steps toward DNA hybridization. A self-limited silane monolayer produced from 3-aminopropyldimethylethoxysilane (APDMES) provides a silane surface density of ~3 nm(-2). Thin (1 h deposition) and thick (19 h deposition) multilayer films are generated from 3-aminopropyltriethoxysilane (APTES), resulting in surfaces with increased roughness compared to the APDMES monolayer. Increased silane surface density is estimated for the 19 h APTES film, due to a ∼32% increase in surface area compared to the APDMES monolayer. High cross-linker coupling efficiencies are measured for all three silane films. DNA immobilization densities are similar for the APDMES monolayer and 1 h APTES. However, the DNA immobilization density is double for the 19 h APTES, suggesting that increased surface area allows for a higher probe attachment. The APDMES monolayer has the lowest DNA target density and hybridization efficiency. This is attributed to the steric hindrance as the random packing limit is approached for DNA double helices (dsDNA, diameter ≥ 2 nm) on a plane. The heterogeneity and roughness of the APTES films reduce this steric hindrance and allow for tighter packing of DNA double helices, resulting in higher hybridization densities and efficiencies. The low steric hindrance of the thin, one to two layer APTES film provides the highest hybridization efficiency of nearly 88%, with 0.21 dsDNA/nm(2). The XPS data also reveal water on the cross-linker-treated surface that is implicated in device aging.

  10. {sup 13}C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Wei, E-mail: weicao@hqu.edu.cn; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-12-15

    Highlights: • {sup 13}C NMR and XPS were successfully used to characterize quaternary ammonium groups in the surface of crop straw based anion adsorbents. • The results obtained from different kinds of crop straw material clearly confirmed the presence of quaternary ammonium groups. • The composition of C-groups and N-groups also were determined by curving fitting of high-resolution XPS C1 and N1 spectra. - Abstract: Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used {sup 13}C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. {sup 13}C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent’s surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that {sup 13}C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  11. 13C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    International Nuclear Information System (INIS)

    Cao, Wei; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-01-01

    Highlights: • 13 C NMR and XPS were successfully used to characterize quaternary ammonium groups in the surface of crop straw based anion adsorbents. • The results obtained from different kinds of crop straw material clearly confirmed the presence of quaternary ammonium groups. • The composition of C-groups and N-groups also were determined by curving fitting of high-resolution XPS C1 and N1 spectra. - Abstract: Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used 13 C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. 13 C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent’s surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that 13 C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  12. Adsorption and interaction of carbon dioxide, formic acid and hydrogen/carbon dioxide mixtures on ( 10 overline10 ) zinc oxide surfaces studied by photoelectron spectroscopy (XPS and UPS)

    Science.gov (United States)

    Au, C. T.; Hirsch, W.; Hirschwald, W.

    Evidence was given for physisorbed CO 2(s) and surface carbonate (CO==) s by XPS and UPS after CO 2 interaction with ( 10 overline10 ) ZnO faces at 100 K. The surface carbonate decomposes above 400 K. Interaction of formic acid with ZnO(10 overline10) induces the formation of condensed and adsorbed HCOOH, formate and hydroxyl groups at 100 K. The formate was characterized and identified by XPS and UPS, and is stable up to 540 K. The same formate species was formed by H 2/CO 2 coadsorption at 300 K and 1 bar total pressure.

  13. Study by X-ray photoelectron spectroscopy (XPS) and radiochemistry (Cl36) of the interaction of chloride ions with a passive film formed on nickel

    International Nuclear Information System (INIS)

    Herbelin, Jean-Marc

    1990-01-01

    This research thesis reports the study of the influence of chlorides on nickel passivation by using a radiochemical method based on the use of the Cl 36 isotope and the X-ray photoelectron spectroscopy (XPS). The first one allows the in-situ determination of the adsorption of chlorides on the surface, or their inclusion in surface films during the electrochemical treatment. The XPS analysis allows the characterization of modifications induced by chlorides in passive films. The obtained results allow a better understanding in the interpretation of the mechanisms of corrosion induced by chloride ions [fr

  14. Concepções sobre drogas por adolescentes escolares

    Directory of Open Access Journals (Sweden)

    Edson Arantes Faria Filho

    2015-06-01

    Full Text Available RESUMOObjetivo:analisar concepções de adolescentes escolares da educação básica sobre drogas em geral.Método:abordagem qualitativa de grupos focais com 16 adolescentes estudantes. Os dados coletados foram analisados por Análise de Conteúdo, onde emergiram as seguintes categorias “Significado de drogas”; “Convivendo com o uso de drogas”; “Opiniões, crenças e atitudes em relação ao uso de drogas” e “Prevenindo o uso indevido de drogas na adolescência”.Resultados:os adolescentes conhecem algumas drogas associando o uso à marginalidade e à criminalidade. Identifi caram fatores que levam ao consumo abusivo de drogas como fácil acesso, uso familiar e com grupos de amigos, ociosidade, abandono escolar e vulnerabilidade característica da adolescência.Conclusão:os resultados demonstram a necessidade da implementação de trabalhos educativos no contexto em que os adolescentes vivem, seja escolar, social e familiar de modo a apoiar e minimizar as diversas vulnerabilidades dos adolescentes.

  15. Partos domiciliares planejados assistidos por enfermeiras obstétricas: transferências maternas e neonatais

    Directory of Open Access Journals (Sweden)

    Joyce Green Koettker

    Full Text Available O presente trabalho trata-se de estudo exploratório-descritivo que teve como objetivo descrever a taxa e as causas de transferência intraparto para o hospital de mulheres assistidas no domicílio por enfermeiras obstétricas e os desfechos desses nascimentos. A amostra foi composta por onze mulheres e seus recém-nascidos, de janeiro de 2005 a dezembro de 2009. Os dados foram coleta-dos em prontuários e cadernetas de saúde e analisados por estatística descritiva. A taxa de transferência foi de 11%, a maioria de nulíparas (63,6%, e todas foram transferidas durante o primeiro período clínico do parto. Os motivos mais frequentes de transferência foram parada de dilatação cervical e progressão da apresentação fetal, e desproporção cefalopélvica. Os escores de Apgar no 1º e 5º minutos foram >7 em 81,8% dos casos e não houve internação em unidade de terapia intensiva neonatal. Neste estudo constatou-se que o parto domiciliar planejado assistido por enfermeiras obstétricas, com protocolo assistencial, apresentou bons resultados maternos e neonatais, mesmo quando a transferência para o hospital foi necessária.

  16. Representações sociais sobre história por jovens e adultos

    Directory of Open Access Journals (Sweden)

    Carina Cavaletti de Carvalho Pedroso

    2014-08-01

    Full Text Available A pesquisa teve por objetivos analisar as representações sociais sobre História por alunos da Educação de Jovens e Adultos e compreender como esses estudantes se percebem inseridos na História. Participaram da pesquisa sessenta e dois alunos do 3º ano do Ensino Médio, modalidade EJA, de escola pública do Estado de São Paulo. Os dados foram coletados pela pesquisadora, por meio de questionário semiestruturado, e foram analisados pela técnica de análise de conteúdo. Os resultados indicam que os participantes representam história como disciplina escolar construída por grandes heróis, ignorando sua participação efetiva na mesma enquanto sujeitos históricos. Esses jovens e adultos apresentam uma concepção que se aproxima da perspectiva tradicional da História, isto é, de uma história essencialmente política e voltada para os grandes acontecimentos. Os resultados sugerem, ainda, que as representações sociais sobre História estariam relacionadas a uma permanência de práticas pouco problematizadoras, presentes na escola dos pesquisados.

  17. Efeito idade-periodo-coorte na mortalidade por cancer do colo uterino

    Directory of Open Access Journals (Sweden)

    Karina Cardoso Meira

    2013-06-01

    Full Text Available OBJETIVO: Estimar o efeito da idade, período e coorte de nascimento na mortalidade por câncer do colo do útero. MÉTODOS: Foram analisados dados de mortalidade por câncer do colo do útero em mulheres ≥ 30 anos nos municípios do Rio de Janeiro, RJ, e São Paulo, SP, de 1980 a 2009. Os dados foram extraídos do Sistema de Informação Sobre Mortalidade. A variação percentual anual estimada foi calculada para os períodos de 1980-1994 e 1995-2009. O efeito da idade, período e coorte de nascimento foi calculado pelo modelo de regressão de Poisson, utilizando funções estimáveis: desvios, curvaturas e drift , por meio da biblioteca Epi do programa estatístico R versão 2.7.2. RESULTADOS: A taxa de mortalidade média do período por 100.000 mulheres foi 15,90 no Rio de Janeiro e 15,87 em São Paulo. Houve redução significativa na mortalidade por câncer do colo do útero nos dois períodos: no Rio de Janeiro, -1,20% (IC95% -2,20;-0,09 e -1,46% (IC95% -2,30;-0,61, e em São Paulo, -2,58% (IC95% -3,41;-1,76 e -3,30% (IC95% -4,30;-2,29. A análise da curvatura dos efeitos indicou tendência de redução do risco de morte nas sucessivas coortes (RR < 1 nas mulheres nascidas após a década de 1960. Observou-se redução acentuada no risco relativo (RR a partir dos anos 2000. CONCLUSÕES: O estudo evidenciou efeito de período na redução das taxas de mortalidade por câncer do colo do útero no período analisado, tendo em vista que houve efeito de proteção (RR < 1 a partir dos anos 2000 e nas mulheres nascidas após a década de 1960.

  18. In Situ Studies of Surface Mobility on Noble Metal Model Catalysts Using STM and XPS at Ambient Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, Derek Robert [Univ. of California, Berkeley, CA (United States)

    2010-06-01

    High Pressure Scanning Tunneling Microscopy (HP-STM) and Ambient Pressure X-ray Photoelectron Spectroscopy were used to study the structural properties and catalytic behavior of noble metal surfaces at high pressure. HP-STM was used to study the structural rearrangement of the top most atomic surface layer of the metal surfaces in response to changes in gas pressure and reactive conditions. AP-XPS was applied to single crystal and nanoparticle systems to monitor changes in the chemical composition of the surface layer in response to changing gas conditions. STM studies on the Pt(100) crystal face showed the lifting of the Pt(100)-hex surface reconstruction in the presence of CO, H2, and Benzene. The gas adsorption and subsequent charge transfer relieves the surface strain caused by the low coordination number of the (100) surface atoms allowing the formation of a (1 x 1) surface structure commensurate with the bulk terminated crystal structure. The surface phase change causes a transformation of the surface layer from hexagonal packing geometry to a four-fold symmetric surface which is rich in atomic defects. Lifting the hex reconstruction at room temperature resulted in a surface structure decorated with 2-3 nm Pt adatom islands with a high density of step edge sites. Annealing the surface at a modest temperature (150 C) in the presence of a high pressure of CO or H2 increased the surface diffusion of the Pt atoms causing the adatom islands to aggregate reducing the surface concentration of low coordination defect sites. Ethylene hydrogenation was studied on the Pt(100) surface using HP-STM. At low pressure, the lifting of the hex reconstruction was observed in the STM images. Increasing the ethylene pressure to 1 Torr, was found to regenerate the hexagonally symmetric reconstructed phase. At room temperature ethylene undergoes a structural rearrangement to form ethylidyne. Ethylidyne preferentially binds at the three-fold hollow sites, which

  19. El recuerdo viaja por Italia

    Directory of Open Access Journals (Sweden)

    Néstor Madrid Malo

    1965-09-01

    Full Text Available Espero que mis lectores puedan acompañarme en este viaje del recuerdo por Italia, en esta travesía restrospectiva por el cuerpo duradero, por el dorso sustantivo - vertebrado dulcemente, ásperamente, por el vasto cinturón apenínico- de un país donde la vida tiene una manera tan suya de ser grata, de transcurrir en todo momento significativamente. Y donde cada instante, cada sitio, está signado de plenitudes inefables, de expresivos modos de mostrársenos e insinuársenos, hasta hacerse todos ellos, por siempre, memorables e insistentes habitantes de nuestros mejores sueños y vigilias.

  20. Characterization of titanium hydride films covered by nanoscale evaporated Au layers: ToF-SIMS, XPS and AES depth profile analysis

    NARCIS (Netherlands)

    Lisowski, W.F.; van den Berg, A.H.J.; Leonard, D.; Mathieu, H.J.

    2000-01-01

    Thin titanium hydride (TiHy) films, covered by ultrathin gold layers, have been compared with the corresponding titanium films after analysis using a combination of time-of-flight SIMS (ToF-SIMS), XPS and AES. The TiHy layers were prepared under UHV conditions by precisely controlled hydrogen

  1. Single-crystal LiNbO.sub.3./sub. surfaces processed in low-temperature hydrogen plasma:XPS, REELS and AFM study

    Czech Academy of Sciences Publication Activity Database

    Turčičová, Hana; Zemek, Josef; Tóht, J.; Drbohlav, Ivo

    2002-01-01

    Roč. 34, - (2002), s. 468-471 ISSN 0142-2421 R&D Projects: GA ČR GA202/98/1285 Grant - others:IAEA(AT) 10031 Institutional research plan: CEZ:AV0Z1010914 Keywords : lithium niobate * radiofrequency plasma * XPS * REELS * AFM Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.071, year: 2002

  2. 13C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    Science.gov (United States)

    Cao, Wei; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-12-01

    Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used 13C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. 13C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent's surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that 13C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  3. A comparative study of the adsorbed Pb(II), Cd (II) and Zn (II) on smectite, kaolinite and illite using XPS

    Czech Academy of Sciences Publication Activity Database

    Melegy, A. A.; Ismael, I. S.; Bastl, Zdeněk

    2005-01-01

    Roč. 58, - (2005), s. 283-290 ISSN 0044-2658 R&D Projects: GA AV ČR KSK4040110 Institutional research plan: CEZ:AV0Z40400503 Keywords : XPS * adsorption * heavy metals * clay minerals * surface complexes Subject RIV: CF - Physical ; Theoretical Chemistry

  4. Local Structure of Nanocrystalline Ru1-xNixO2-delta Dioxide and Its Implications for Electrocatalytic Behavior-An XPS and XAS Study

    Czech Academy of Sciences Publication Activity Database

    Petrykin, Valery; Bastl, Zdeněk; Franc, Jiří; Macounová, Kateřina; Makarova, Marina; Mukerjee, S.; Ramaswamy, N.; Spirovová, Ilona; Krtil, Petr

    2009-01-01

    Roč. 113, č. 52 (2009), s. 21657-21666 ISSN 1932-7447 R&D Projects: GA AV ČR IAA400400906 Institutional research plan: CEZ:AV0Z40400503 Keywords : oxygen evolution reaction * nanocrystalline * XPS study Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.224, year: 2009

  5. Growth Mode Study of MgCl2 on Ti (0001 and SiO2 under Ultra High Vacuum by XPS

    Directory of Open Access Journals (Sweden)

    S. Karakalos

    2012-12-01

    Full Text Available The growth mode of MgCl2 on Ti (0001 and on SiO2 grown on Si (100 was investigated by X-ray Photoelectron Spectroscopy (XPS under UHV conditions. Magnesium chloride grows on both Ti (0001 single crystal and SiO2 following the Frank-van der Merve, (FM growth mode.

  6. Extended study on oxidation behaviors of UN0.68 and UN1.66 by XPS

    Science.gov (United States)

    Luo, Lizhu; Hu, Yin; Pan, Qifa; Long, Zhong; Lu, Lei; Liu, Kezhao; Wang, Xiaolin

    2018-04-01

    The surface oxidation behaviors of UN0.68 and UN1.66 thin films are investigated by X-ray photoelectron spectroscopy (XPS), and the traditional U4f/N1s, O1s, valence band spectra as well as the unconventional U4d and U5d spectra are collected for the understanding of their oxidation behavior in-depth. Similar asymmetrical peak shape of the U4f spectra to uranium is observed for both uranium nitrides, despite of a slight shift to higher energy side for UN1.66 clean surface. However, significant difference among the corresponding spectra of UN0.68 and UN1.66 during oxidation reveals the distinctive properties of each own. The coexistence of UO2-x, UO2 and UO2-x.Ny on UN0.68 surface results in the peculiar features of U4f spectra as well as the others within the XPS energy scale, where peaks of the oxidized species firstly shift to higher energy side compared to the clean surface, and then return closely towards those of stoichiometric UO2. For UN1.66, the generation of U-N-O ternary compounds on the surface is identified with the symmetrical U4f peaks at 379.9eV and 390.8 eV, which locate intermediate between UO2 and UN1.66, and gradually expanding to higher energy side during the progressive oxidation. Furthermore, the formation of N-O species on UN1.66 surface is also detected as an oxidation product. The metallic character of UN1.66 is identified by the intense signal at Fermi level, which is greatly suppressed by the increasing oxygen exposure and implies the weakening metallic properties of the as-generated U-N-O compounds. Higher uranium oxides, such as UO3 and U4O9, are deduced to be the final oxidation products, and a multistage mechanism for UN1.66 following the exposure to oxygen is discussed.

  7. Infarto cerebral e edema avaliação prognóstico-evolutiva por sinais neurológicos

    Directory of Open Access Journals (Sweden)

    Rubens José Gagliardi

    1991-03-01

    Full Text Available Trata-se de estudo prospectivo abrangendo 92 doentes com infarto cerebral (IC. O seguimento foi feito durante 10 dias com avaliação diária, sendo os doentes analisados por escala de notas para diferentes sinais costumeiramente pesquisados nesses casos. A metodologia foi especialmente desenvolvida no sentido de analisar exclusivamente alterações devidas ao edema oriundo da isquemia e IC. As conclusões foram obtidas por comparação isolada das médias das notas de cada sinal com a média do total das notas. Os resultados mostram que o exame da «consciência», isoladamente, é o melhor parâmetro clínico para averiguar a evolução do doente após um IC, sem outras complicações que não o edema.

  8. Responsabilidade civil por abandono afetivo

    OpenAIRE

    Fidélis, Maria de Lourdes

    2013-01-01

    Este estudo tem por objetivo a análise da responsabilidade civil por abandono afetivo na relação paterno-filial a partir de recentes decisões dos tribunais brasileiros. Inicialmente discorre sobre a evolução da família contemporânea. Examina os elementos da responsabilidade civil objetivando uma interseção entre o novo Direito de Família e as transformações no dever de indenizar. A partir de dois casos paradigmáticos escolhidos busca-se encontrar os fundamentos e finalidades das demandas por ...

  9. Single-layer ZnS supported on Au(111): A combined XPS, LEED, STM and DFT study

    Science.gov (United States)

    Deng, Xingyi; Sorescu, Dan C.; Lee, Junseok

    2017-04-01

    Single-layer of ZnS, consisting of one atomic layer of ZnS(111) plane, has been grown on Au(111) and characterized using X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). While the LEED measurement indicates a coincidence structure of ZnS-(3×3)/Au(111)-(4×4), high resolution STM images reveal hexagonal unit cells of 6.7×6.7 Å2 and 11.6×11.6 Å2, corresponding to √3 and 3 times the unit cell of the ideal zincblende ZnS-(1×1), respectively, depending on the tunneling conditions. Calculations based on density functional theory (DFT) indicate a significantly reconstructed non-planar structure of ZnS single-layer on Au(111) with 2/3 of the S anions being located nearly in the plane of the Zn cations and the rest 1/3 of the S anions protruding above the Zn plane. The calculated STM image shows similar characteristics to those of the experimental STM image. Additionally, the DFT calculations reveal the different bonding nature of the S anions in ZnS single-layer supported on Au(111).

  10. XPS Study on the Stability and Transformation of Hydrate and Carbonate Phases within MgO Systems

    Directory of Open Access Journals (Sweden)

    Vanessa Rheinheimer

    2017-01-01

    Full Text Available MgO cements have great potential for carbon sequestration as they have the ability to carbonate and gain strength over time. The hydration of reactive MgO occurs at a similar rate as ordinary Portland cement (PC and forms brucite (Mg(OH2, magnesium hydroxide, which reacts with CO2 to form a range of hydrated magnesium carbonates (HMCs. However, the formation of HMCs within the MgO–CO2–H2O system depends on many factors, such as the temperature and CO2 concentration, among others, which play an important role in determining the rate and degree of carbonation, the type and stability of the produced HMCs and the associated strength development. It is critical to understand the stability and transformation pathway of HMCs, which are assessed here through the use of X-ray photoelectron spectroscopy (XPS. The effects of the CO2 concentration (in air or 10% CO2, exposure to high temperatures (up to 300 °C and curing period (one or seven days are reported. Observed changes in the binding energy (BE indicate the formation of different components and the transformation of the hydrated carbonates from one form to another, which will influence the final performance of the carbonated blends.

  11. X-ray photoemission spectroscopy (XPS) and extended x-ray absorption fine structure (EXAFS) studies of silicate based glasses

    International Nuclear Information System (INIS)

    Karim, D.; Lam, D.J.

    1979-01-01

    The application of the x-ray photoemission spectroscopy (XPS) technique to study the electronic structure and bonding of heavy metal oxides in alkali- and alkali-earth-silicate glasses had been demonstrated. The bonding characteristics of the iron oxide and uranium oxide in sodium silicate glasses were deduced from the changes in the oxygen 1s levels and the heavy metal core levels. It is reasonable to expect that the effect of leaching on the heavy metal ions can be monitored using the appropriate core levels of these ions. To study the effect of leaching on the glass forming network, the valence band structure of the bridging and nonbridging oxygens in sodium silicate glasses were investigated. The measurement of extended x-ray absorption fine-structure (EXAFS) is a relatively new analytical technique for obtaining short range (<5 A) structural information around atoms of a selected species in both solid and fluid systems. Experiments have recently begun to establish the feasibility of using EXAFS to study the bonding of actinides in silicate glasses. Because of the ability of EXAFS to yield specific structural data even in complex multicomponent systems, it could prove to be an invaluable tool in understanding glass structure

  12. The Activation of Non-evaporable Getters Monitored by AES, XPS, SSIMS and Secondary Electron Yield Measurements

    CERN Document Server

    Scheuerlein, C

    2002-01-01

    In this thesis the potential of the three classical surface analysis techniques Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SSIMS) for the characterisation of non-evaporable getter (NEG) materials is assessed and artefacts are described. The various NEG samples have been analysed in the context of the development of NEG thin film coatings for use in accelerator ultra high vacuum (UHV) systems. The secondary electron yield (SEY), which is a functional surface property of great importance for the application of NEG to accelerators, has been measured. The maximum SEY of an air exposed TiZr and TiZrV coating can be reduced from above 2.0 to below 1.1 during a 2 h heat treatment at 250 and 200 °C, respectively. Saturating an activated TiZrV surface in UHV increases the maximum SEY by about 0.1. Thus, in UHV the SEY of an activated NEG coating does not exceed the threshold value of 1.35, above which multipacting is predicted to occur in th...

  13. XPS study of Pd/Co multilayers: identification of Pd and Co interface bonding states by pattern recognition methods

    Science.gov (United States)

    Lesiak, B.; Zemek, J.; de Haan, P.; Jozwik, A.

    1996-02-01

    Artificially structured magnetic superlattices consisting of ultrathin Pd/Co multilayers with varying thickness exhibit strong perpendicular magnetic anisotropy. This particular property in such systemsis strongly correlated with the structure of the interface and its local environment. In the present work, the interface of Pd/Co in two multilayer system was sampled applying X-ray photoelectron spectroscopy (XPS) and sophisticated pattern recognition methods for spectrum processing, i.e. the k-nearest neighbour rule (kNN) and a clusterization algorithm. For the first time, the fuzzy kNN approach has been applied for investigating surface effects. The above methods consider the lineshape of photoelectron spectra recorded for a set of reference samples, evaluate the criteria for the optimum separation of groups, and identity the unknown samples. Photoelectron Pd 3d and Co 2p spectra were recorded from metallic Pd, Co and CoPd solid solutions with varying concentrations of constituents, and from Pd/Co magnetic multilayers. The applied methods were able to identify the alloying of Pd and Co atoms at the Pd/Co interface of the multilayer systems with different concentrations of component involved. The results obtained indicate that both interfaces have finite thickness, which may influence the magnetic properties of the investigated systems.

  14. Adsorption of sodium dodecyl sulfate and sodium dodecyl phosphate on aluminum, studied by QCM-D, XPS, and AAS.

    Science.gov (United States)

    Karlsson, Philip M; Palmqvist, Anders E C; Holmberg, Krister

    2008-12-02

    The adsorption of two anionic surfactants, sodium dodecyl sulfate (SDS) and sodium dodecyl phosphate (SDP), at surfaces of aluminum and aluminum oxide has been studied by means of atomic absorption spectrometry (AAS), X-ray photoelectron spectroscopy (XPS), and quartz crystal microbalance with dissipation monitoring (QCM-D). It was shown that more SDP than SDS binds to the surface and that SDP prevents dissolution of aluminum in water whereas SDS does not. This was not obvious, since the adsorption isotherms of the two surfactants to aluminum pigment powder are quite similar, as shown in an earlier work. The decreased aluminum dissolution with SDP compared to SDS was explained by the formation of a more compact protective layer with less permeability on the aluminum surface with SDP than with SDS. This is explained by differences in complexing ability between the surfactants and the aluminum pigment surface. While SDP is expected to form an inner-sphere complex with aluminum, leading to a lower accessibility of aluminum sites to water, SDS is likely to form a weaker outer-sphere complex.

  15. An XPS study of the stability of Fomblin Z25 on the native oxide of aluminum. [x ray photoelectron spectroscopy

    Science.gov (United States)

    Herrera-Fierro, Pilar; Pepper, Stephen V.; Jones, William R.

    1991-01-01

    Thin films of Fomblin Z25, a perfluoropolyalkylether lubricant, were vapor deposited onto clean, oxidized aluminum and sapphire surfaces, and their behavior at different temperatures was studied using x ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). It was found that the interfacial fluid molecules decompose on the native oxide at room temperature, and continue to decompose at elevated temperatures, as previous studies had shown to occur on clean metal. TDS indicated that different degradation mechanisms were operative for clean and oxidized aluminum. On sapphire substrates, no reaction was observed at room temperature. Our conclusion is that the native oxide of aluminum is neither passive nor protective towards Fomblin Z25. At high temperatures (150 C) degradation of the polymer on sapphire produced a debris layer at the interface with a chemical composition similar to the one formed on aluminum oxide. Rubbing a Fomblin film on a single crystal sapphire also induced the decomposition of the lubricant in contact with the interface and the formulation of a debris layer.

  16. Probing Co/Si interface behaviour by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM)

    International Nuclear Information System (INIS)

    Pan, J.S.; Liu, R.S.; Tok, E.S.

    2006-01-01

    In this work, we investigate the Co-Si reaction, the Co growth mode at room temperature, diffusion behaviour as well as morphology evolution during annealing on both H-terminated and clean Si(001) and Si(111) surfaces. From in-situ X-ray photoelectron spectroscopy (XPS) investigation, 'Co-Si' reaction appears to occur on both H-terminated and clean surfaces at room temperature (RT) and the silicide crystallinity is improved upon annealing. Co growth mode on H-terminated Si surfaces occurs in a pseudo layer-by-layer manner while small close-packed island growth mode is observed on the clean Si surface. Upon annealing at different temperatures, Co atom concentration decreases versus annealing time, which in part is attributed to Co atoms inward diffusion. The diffusion behaviour on both types of surfaces demonstrates a similar trend. Morphology study using ex-situ atomic force microscopy (AFM) shows that the islands formed on Si(001) surface after annealing at 700 degree C are elongated with growth directions alternate between the two perpendicular [110] and [110] directions. Triangular islands are observed on Si(111) surface. (authors)

  17. Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al2O3-films

    Directory of Open Access Journals (Sweden)

    Jörg Haeberle

    2013-11-01

    Full Text Available We report on results on the preparation of thin (2O3 films on silicon substrates using thermal atomic layer deposition (T-ALD and plasma enhanced atomic layer deposition (PE-ALD in the SENTECH SI ALD LL system. The T-ALD Al2O3 layers were deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate over 4” wafers and correlate them to X-ray photoelectron spectroscopy (XPS results. The 200 °C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is not influenced significantly. Initial state energy shifts in all PE-ALD samples are observed which we attribute to a net negative charge within the films.

  18. Oxygen accumulation on metal surfaces investigated by XPS, AES and LEIS, an issue for sputter depth profiling under UHV conditions

    Science.gov (United States)

    Steinberger, R.; Celedón, C. E.; Bruckner, B.; Roth, D.; Duchoslav, J.; Arndt, M.; Kürnsteiner, P.; Steck, T.; Faderl, J.; Riener, C. K.; Angeli, G.; Bauer, P.; Stifter, D.

    2017-07-01

    Depth profiling using surface sensitive analysis methods in combination with sputter ion etching is a common procedure for thorough material investigations, where clean surfaces free of any contamination are essential. Hence, surface analytic studies are mostly performed under ultra-high vacuum (UHV) conditions, but the cleanness of such UHV environments is usually overrated. Consequently, the current study highlights the in principle known impact of the residual gas on metal surfaces (Fe, Mg, Al, Cr and Zn) for various surface analytics methods, like X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and low-energy ion scattering (LEIS). The investigations with modern, state-of-the-art equipment showed different behaviors for the metal surfaces in UHV during acquisition: (i) no impact for Zn, even after long time, (ii) solely adsorption of oxygen for Fe, slight and slow changes for Cr and (iii) adsorption accompanied by oxide formation for Al and Mg. The efficiency of different counter measures was tested and the acquired knowledge was finally used for ZnMgAl coated steel to obtain accurate depth profiles, which exhibited before serious artifacts when data acquisition was performed in an inconsiderate way.

  19. Porøse materialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2000-01-01

    Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM).......Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM)....

  20. KOKO KL.xps

    African Journals Online (AJOL)

    HP Pro 2000

    En Côte d'Ivoire, le cacaoyer (Theobroma cacao L.) est traditionnellement cultivé selon un système extensif et itinérant, utilisant du matériel végétal peu performant. Les rendements en cacao sont donc faible (260 à 600 kg·ha-1·an-1). Pour améliorer la productivité des cacaoyères, les chercheurs ivoiriens ont mis au point.

  1. TOURE ALI.xps

    African Journals Online (AJOL)

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    financial and economic parity prices of different brands of imported-rice. Results from the PAM base-scenario model showed that under the evaluated CET policy irrigated rice production, activities were competitive and private operators had positive financial gains, meaning that private profitability was positive. Moreover, the.

  2. KAMBIRE OLLO.xps

    African Journals Online (AJOL)

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    une étude bactériologique. Pourtant, le complexe lagunaire Aby-Tendo-Ehy présente, sur les berges, des campements, des villages et des villes. L'étude vise à évaluer le ..... pement durable, de l'Environnement et des. Parcs du Québec, 23 p.

  3. VANGA AF.xps

    African Journals Online (AJOL)

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    Elle implique une approche participative des populations locales à la gestion de la forêt classée en général, ..... PO_ATTA-KOUACOUtexte.pdf. Bourgeot M. 1999. Horizons nomades en Afrique sahélienne : sociétés, développement et démocratie. Karthala, Paris, 291 p. Buttoud G. 1995. La forêt et l'Etat en Afrique sèche.

  4. YABILE KR.xps

    African Journals Online (AJOL)

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    atteindre l'autosuffisance alimentaire (hormis le riz, dont la situation s'est considérablement dégradée depuis 1977). Selon l'Institut National de la Statistique (INS, 2008) le taux de ..... Tableau 2 : Définition des variables du modèle. Definition of ...

  5. MOUTSINGA.xps

    African Journals Online (AJOL)

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    L'étude vise à évaluer le régime alimentaire des poissons-chats du bassin de la rivière Léfini selon les ... 3 espèces de poissons, en fonction des saisons, le coefficient de condition, le pourcentage d'occurrence, ... subsidence, the food regime of C. ornatus, varied more than in periods of rise in the water level, with high.

  6. SOUMAHORO A..xps

    African Journals Online (AJOL)

    AISA

    avant le semis dans des boîtes de Pétri, sur du papier filtre ou sur le milieu de base de Murashige et Skoog. (MS). Sur le papier filtre, l'imbibition dans l'eau distillée des graines, pendant 24 heures, a donné le meilleur taux de germination (59,01 %). La stérilisation des graines dans l'acide sulfurique 96 % durant 1 minute,.

  7. BAMBA Vamoussa.xps

    African Journals Online (AJOL)

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    V. BAMBA. Unité de Formation et de Recherche en Gestion Commerce et Economie Appliquée (GCEA)/l'Institut National. Polytechnique(INP HB). ..... Kouassi Y. 1994. Optimisation de la main d'oeuvre en exploitation hévéïcole. Mémoire de fin de cycle ingénieur agronome ESA/INP-HB. (Côte d`Ivoire). 69 p. Tuo A. 2008.

  8. OUATTARA BADIORI.xps

    African Journals Online (AJOL)

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    stockage et la disponibilité des nutriments au profit des plantes et intervient comme source de nutriments et d'énergie pour les micro- organismes et la macrofaune du sol (Cheshire,. 1979 ; Hu et al., 1997). .... d'application également variables (2 à 3 ans). Les labours ont été réalisés, en culture attelée ou motorisée, à des ...

  9. DJODJOUWIN 2.xps

    African Journals Online (AJOL)

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    Evaluation morphologiques des espèces introduites. A travers un échantillonnage aléatoire simple,. 30 individus de chaque espèce et par zone ont été sélectionnés et marqués à la peinture. Périodiquement, les mesures de hauteur et de diamètre sont effectuées sur les individus sélectionnés et marqués. En zone soudano ...

  10. DJODJOUWIN 1.xps

    African Journals Online (AJOL)

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    La présente étude vise à analyser le comportement de 7 espèces végétales ligneuses : Khaya senegalensis,. Khaya grandifoliola, Holoptelea grandis, Afzelia africana, Terminalia superba, Gmelina arborea et Tectona grandis introduites en plantations d'enrichissement sous 3 types de couvert végétal et de sol. A cet effet, 3.

  11. YABILE KR.xps

    African Journals Online (AJOL)

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    favorable à la mise en œuvre d'une politique agricole visant la couverture des besoins alimentaires nationaux. ... surévaluation du taux de change du franc CFA ... Le taux de couverture national des besoins est de 44,6 % pour la viande et abats et de 12,6 % pour le lait et les produits laitiers. Au cours de ces dernières.

  12. VANGA.xps

    African Journals Online (AJOL)

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    Hence, to combat food insecurity, a rice production program has been initiated in Côte d'Ivoire. In the lakes region, rice was an alternative for poverty alleviation linked to the progressive loss ... sans mesures d'accompagnement, les riziculteurs n'étant pas organisés, n'ont pu prendre le relais (Dozon, 1985). La libéralisation.

  13. COULIBALY Kalifa.xps

    African Journals Online (AJOL)

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    biomasse par unité de surface, avec une qualité meilleure qu'en système de culture conventionnel. Mots clés : Intensification écologique, système à .... hauteurs d'eau de 749, 842 et 845,5 mm, respectivement pour le village de Koumbia, ..... niébé que pour l'association. Il n'y a pas eu de traitement insecticide sur le maïs.

  14. The Psychology of Music, editado por Diana Deutsch, 3ª edição: resenha dos capítulos 10 a 13

    OpenAIRE

    Ricieri Carlini Zorzal

    2016-01-01

    O presente texto traz uma resenha de quatro capítulos da terceira edição do livro The Psychology of Music, editado por Diana Deutsch. Nominalmente, são analisados os seguintes capítulos: 10) Performance musical: movimento e coordenação, de autoria de Caroline Palmer; 11) Desenvolvimento musical, de autoria de Laurel Trainor e Erin Hannon; 12) Música e habilidades cognitivas, de autoria de Glenn Schellenberg e Michael Weiss; e 13) As fundações biológicas da música: insights da amusia congênita...

  15. The Psychology of Music, editado por Diana Deutsch, 3ª edição: resenha dos quatro capítulos finais

    OpenAIRE

    Ricieri Carlini Zorzal

    2015-01-01

    O presente texto traz uma resenha dos quatro capítulos finais da terceira edição do livro The Psychology of Music, editado por Diana Deutsch. Dessa forma, são analisados, individualmente, os seguintes capítulos: 14) Plasticidade cerebral induzida pelo treinamento musical, de autoria de Catherine Wan e Gottfried Schlaug; 15) Música e emoção, de autoria de Patrik Juslin e John Sloboda; 16) Cognição musical comparativa: estudos entre espécies e entre culturas, de autoria de Aniruddh Patel e Stev...

  16. The Psychology of Music, editado por Diana Deutsch, 3ª edição: resenha dos capítulos 10 a 13

    Directory of Open Access Journals (Sweden)

    Ricieri Carlini Zorzal

    2016-03-01

    Full Text Available O presente texto traz uma resenha de quatro capítulos da terceira edição do livro The Psychology of Music, editado por Diana Deutsch. Nominalmente, são analisados os seguintes capítulos: 10 Performance musical: movimento e coordenação, de autoria de Caroline Palmer; 11 Desenvolvimento musical, de autoria de Laurel Trainor e Erin Hannon; 12 Música e habilidades cognitivas, de autoria de Glenn Schellenberg e Michael Weiss; e 13 As fundações biológicas da música: insights da amusia congênita, de autoria de Isabelle Peretz.

  17. Limpeza clonal de mudas de videira infectadas por Xanthomonas campestris pv. viticola

    Directory of Open Access Journals (Sweden)

    Adriano Márcio Freire Silva

    2013-03-01

    Full Text Available O cancro bacteriano da videira é causado por Xanthomonas campestris pv. viticola (Xcv. Visando à limpeza clonal de mudas de 'Red Globe', foram estudados: tamanho ideal de ápices e gemas axilares para cultivo em meio de Galzy modificado (MGM; efeito da termoterapia (38ºC/30 dias; e ação de antibióticos na eliminação de Xcv em videiras infectadas. Os percentuais de contaminação por Xcv e de regeneração foram analisados, e as plantas obtidas foram indexadas em meio ágar nutritivo-dextrose-extrato de levedura-ampicilina (NYDAM, seguindo-se teste de patogenicidade. O cultivo de explantes com 3 mm possibilitou a obtenção de plantas livres da bactéria, com regeneração 14,3 vezes maior que explantes com 1 mm. A termoterapia de mudas infectadas, associada ao cultivo in vitro, não eliminou o patógeno. O cultivo de explantes com 10 mm, durante 40 dias em MGM + cefotaxima (300 mg L-1, proporcionou limpeza clonal das mudas. A indexação de plantas de videira regeneradas in vitro, quanto à infecção por Xcv utilizando NYDAM, seguida de teste de patogenicidade, é uma alternativa econômica e eficiente para produção de mudas de alta qualidade fitossanitária.

  18. Agentes limitantes à implantação de Pinus taeda L. por semeadura direta.

    Directory of Open Access Journals (Sweden)

    Vilmar Luciano Mattei

    2009-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Este trabalho analisa a possibilidade de implantação de povoamentos de Pinus taeda por semeadura direta, combinando 4 épocas de semeadura; 3 técnicas de preparo do solo e 2 sistemas de implantação, utilizando 5 sementes por ponto de semeadura. No campo foram analisados os danos causados por agentes bióticos e não bióticos e o número de pontos com pelo menos uma planta. A análise dos resultados permitiu determinar que os pássaros foram os principais destruidores de sementes, principalmente na fase inicial de emergência,. As formigas constituem-se em pragas de alto risco para a semeadura direta da espécie. A utilização de protetores foi indispensável para a semeadura direta de Pinus taeda e o outono foi a melhor época de semeadura.

  19. [XPS Greenlight photoselective vaporization for benign prostatic hyperplasia: analysis of the learning curve and contribution of transrectal ultrasound monitoring].

    Science.gov (United States)

    Misrai, V; Faron, M; Elman, B; Bordier, B; Portalez, D; Guillotreau, J

    2013-09-01

    The aim of this study was to analyze the XPS laser learning curve of one single surgeon with no previous experience of PVP and the impact of the use of reel time transrectal ultrasound (TRUS) monitoring. Retrospective analysis of the first 100 patients: group 1 (1st-49th patient without TRUS) and group 2 (50th-100th with TRUS). The learning curve was analyzed through technical variables: vaporization time/intervention time (VT/IT) (%), energy delivered (J)/prostate volume (J/mL) and delivered energy (J/s or Watt), peroperative conversion into monopolar transurethral resection, postoperative complication, duration of catheterization and hospitalization and evolution of International Prostate Symptom Score (IPSS), PSA level, prostate residual volume and Qmax. Relationships between variables were evaluated by analysing the covariance (R 2 software. 14.2). A significant increase in VT/IT (P=0.0001) and the energy delivered per mL prostate (P=0.043) was reported in group 1. The average energy delivered per second was significantly higher in group 2 (P=0.0016). No difference was observed in terms of intra- or postoperative complication and catheterization time. The duration of hospitalization was significantly shorter in group 2 (P=0.03). The use of TRUS was associated with a gain of energy delivered by prostate volume at the end of learning curve (P=0.018). Prostate residual volume was significantly lower in the group 2 (P=0.0004). In our experience, 50 procedures are required to achieve the learning curve of PVP. The use of reel time TRUS would increase the energy delivered by prostate volume. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  20. Oxygen accumulation on metal surfaces investigated by XPS, AES and LEIS, an issue for sputter depth profiling under UHV conditions

    Energy Technology Data Exchange (ETDEWEB)

    Steinberger, R., E-mail: roland.steinberger@jku.at [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Celedón, C.E., E-mail: carlos.celedon@usm.cl [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Departamento de Física, Universidad Técnica Federico Santa María, Valaparaíso, Casilla 110-V (Chile); Bruckner, B., E-mail: barbara.bruckner@jku.at [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Roth, D., E-mail: dietmar.roth@jku.at [Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Duchoslav, J., E-mail: jiri.duchoslav@jku.at [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Arndt, M., E-mail: martin.arndt@voestalpine.com [voestalpine Stahl GmbH, voestalpine-Straße 3, 4031 Linz (Austria); Kürnsteiner, P., E-mail: p.kuernsteiner@mpie.de [Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); and others

    2017-07-31

    Highlights: • Investigation on the impact of residual gas prevailing in UHV chambers. • For some metals detrimental oxygen uptake could be observed within shortest time. • Totally different behavior was found: no changes, solely adsorption and oxidation. • The UHV residual gas may severely corrupt results obtained from depth profiling. • A well-considered data acquisition sequence is the key for reliable depth profiles. - Abstract: Depth profiling using surface sensitive analysis methods in combination with sputter ion etching is a common procedure for thorough material investigations, where clean surfaces free of any contamination are essential. Hence, surface analytic studies are mostly performed under ultra-high vacuum (UHV) conditions, but the cleanness of such UHV environments is usually overrated. Consequently, the current study highlights the in principle known impact of the residual gas on metal surfaces (Fe, Mg, Al, Cr and Zn) for various surface analytics methods, like X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and low-energy ion scattering (LEIS). The investigations with modern, state-of-the-art equipment showed different behaviors for the metal surfaces in UHV during acquisition: (i) no impact for Zn, even after long time, (ii) solely adsorption of oxygen for Fe, slight and slow changes for Cr and (iii) adsorption accompanied by oxide formation for Al and Mg. The efficiency of different counter measures was tested and the acquired knowledge was finally used for ZnMgAl coated steel to obtain accurate depth profiles, which exhibited before serious artifacts when data acquisition was performed in an inconsiderate way.

  1. Surface study of stainless steel electrode deposition from soil electrokinetic (EK) treatment using X-ray photoelectron spectroscopy (XPS)

    Energy Technology Data Exchange (ETDEWEB)

    Embong, Zaidi, E-mail: zaidi@uthm.edu.my [Faculty of Science, Technology and Human Development, Universiti Tun Hussien Onn Malaysia (UTHM) 86400, Parit Raja, Batu, Johor (Malaysia); Research Centre for Soft Soils (RECESS), Office for Research, Innovation, Commercialization and Consultancy Management (ORICC), Universiti Tun Hussien Onn Malaysia UTHM 86400, Parit Raja, Batu, Johor (Malaysia); Johar, Saffuwan [Faculty of Science, Technology and Human Development, Universiti Tun Hussien Onn Malaysia (UTHM) 86400, Parit Raja, Batu, Johor (Malaysia); Tajudin, Saiful Azhar Ahmad [Research Centre for Soft Soils (RECESS), Office for Research, Innovation, Commercialization and Consultancy Management (ORICC), Universiti Tun Hussien Onn Malaysia UTHM 86400, Parit Raja, Batu, Johor (Malaysia); Sahdan, Mohd Zainizan [Microelectronics and Nanotechnology Centre (MiNT-SRC), Office for Research, Innovation, Commercialization and Consultancy Management (ORICC), Universiti Tun Hussien Onn Malaysia UTHM 86400, Parit Raja, Batu, Johor (Malaysia)

    2015-04-29

    Electrokinetic (EK) remediation relies upon application of a low-intensity direct current through the soil between stainless steel electrodes that are divided into a cathode array and an anode array. This mobilizes charged species, causing ions and water to move toward the electrodes. Metal ions and positively charged organic compounds move toward the cathode. Anions such as chloride, fluoride, nitrate, and negatively charged organic compounds move toward the anode. Here, this remediation techniques lead to a formation of a deposition at the both cathode and anode surface that mainly contributed byanion and cation from the remediated soil. In this research, Renggam-Jerangau soil species (HaplicAcrisol + RhodicFerralsol) with a surveymeter reading of 38.0 ± 3.9 μR/hr has been investigation in order to study the mobility of the anion and cation under the influence electric field. Prior to the EK treatment, the elemental composition of the soil and the stainless steel electrode are measured using XRF analyses. Next, the soil sample is remediated at a constant electric potential of 30 V within an hour of treatment period. A surface study for the deposition layer of the cathode and anode using X-ray Photoelectron spectroscopy (XPS) revealed that a narrow photoelectron signal from oxygen O 1s, carbon, C 1s silica, Si 2p, aluminium, Al 2p and chromium, Cr 2p exhibited on the electrode surface and indicate that a different in photoelectron intensity for each element on both electrode surface. In this paper, the mechanism of Si{sup 2+} and Al{sup 2+} cation mobility under the influence of voltage potential between the cathode and anode will be discussed in detail.

  2. Surface study of stainless steel electrode deposition from soil electrokinetic (EK) treatment using X-ray photoelectron spectroscopy (XPS)

    International Nuclear Information System (INIS)

    Embong, Zaidi; Johar, Saffuwan; Tajudin, Saiful Azhar Ahmad; Sahdan, Mohd Zainizan

    2015-01-01

    Electrokinetic (EK) remediation relies upon application of a low-intensity direct current through the soil between stainless steel electrodes that are divided into a cathode array and an anode array. This mobilizes charged species, causing ions and water to move toward the electrodes. Metal ions and positively charged organic compounds move toward the cathode. Anions such as chloride, fluoride, nitrate, and negatively charged organic compounds move toward the anode. Here, this remediation techniques lead to a formation of a deposition at the both cathode and anode surface that mainly contributed byanion and cation from the remediated soil. In this research, Renggam-Jerangau soil species (HaplicAcrisol + RhodicFerralsol) with a surveymeter reading of 38.0 ± 3.9 μR/hr has been investigation in order to study the mobility of the anion and cation under the influence electric field. Prior to the EK treatment, the elemental composition of the soil and the stainless steel electrode are measured using XRF analyses. Next, the soil sample is remediated at a constant electric potential of 30 V within an hour of treatment period. A surface study for the deposition layer of the cathode and anode using X-ray Photoelectron spectroscopy (XPS) revealed that a narrow photoelectron signal from oxygen O 1s, carbon, C 1s silica, Si 2p, aluminium, Al 2p and chromium, Cr 2p exhibited on the electrode surface and indicate that a different in photoelectron intensity for each element on both electrode surface. In this paper, the mechanism of Si 2+ and Al 2+ cation mobility under the influence of voltage potential between the cathode and anode will be discussed in detail

  3. Análise da qualidade superficial e dimensional em peças produzidas por modelagem por deposição de material fundido (FDM

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Pereira Mello

    2010-08-01

    Full Text Available A prototipagem rápida vem crescendo cada vez mais como uma opção na busca de redução do tempo e dos riscos no processo de desenvolvimento de produtos. Contudo, as peças produzidas por modelagem por deposição de material fundido (FDM podem sofrer variações na rugosidade e precisão dimensional, dependendo de parâmetros como espessura do filete depositado, sentido da orientação da fabricação da peça, tipo de deposição de camada e geometria do corpo de prova. A literatura é rica em trabalhos dessa natureza a respeito de protótipos rápidos produzidos por outras tecnologias de prototipagem, mas o mesmo não acontece com o FDM. Portanto, a presente pesquisa busca analisar a qualidade superficial e dimensional de protótipos rápidos produzidos com a tecnologia de FDM, por meio de um projeto experimental. De acordo com os dados analisados, foi possível afirmar que algumas variáveis selecionadas como fator principal, ou a interação entre elas, tiveram efeito sobre a resposta rugosidade e nenhum efeito sobre a resposta precisão dimensional. Conclui-se que, na produção de protótipos onde o acabamento superficial for importante, cuidados devem ser tomados na especificação dos parâmetros da máquina, uma vez que a rugosidade da peça final prototipada vai depender fortemente da interação entre os mesmos.

  4. The (001) 3C SiC surface termination and band structure after common wet chemical etching procedures, stated by XPS, LEED, and HREELS

    Science.gov (United States)

    Tengeler, Sven; Kaiser, Bernhard; Ferro, Gabriel; Chaussende, Didier; Jaegermann, Wolfram

    2018-01-01

    The (001) surface of cubic silicon carbide (3C SiC) after cleaning, Ar sputtering and three different wet chemical etching procedures was thoroughly investigated via (angle resolved) XPS, HREELS, and LEED. While Ar sputtering was found to be unsuitable for surface preparation, all three employed wet chemical etching procedures (piranha/NH4F, piranha/HF, and RCA) provide a clean surface. HF as oxide removal agent tends to result in fluorine traces on the sample surface, despite thorough rinsing. All procedures yield a 1 × 1 Si-OH/C-H terminated surface. However, the XPS spectra reveal some differences in the resulting surface states. NH4F for oxide removal produces a flat band situation, whereas the other two procedures result in a slight downward (HF) or upward (RCA) band bending. Because the band bending is small, it can be concluded that the number of unsaturated surface defects is low.

  5. XPS and ToF-SIMS analysis of natural rubies and sapphires heat-treated in a reducing (5 mol% H2/Ar) atmosphere

    International Nuclear Information System (INIS)

    Achiwawanich, S.; James, B.D.; Liesegang, J.

    2008-01-01

    Surface effects on Mong Hsu rubies and Kanchanaburi sapphires after heat treatment in a controlled reducing atmosphere (5 mol% H 2 /Ar) have been investigated using advanced surface science techniques including X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Visual appearance of the gemstones is clearly affected by the heat treatment in a reducing atmosphere. Kanchanaburi sapphires, in particular, exhibit Fe-containing precipitates after the heat treatment which have not been observed in previous studies under an inert atmosphere. Significant correlation between changes in visual appearance of the gemstones and variations in surface concentration of trace elements, especially Ti and Fe are observed. The XPS and ToF-SIMS results suggest that; (1) a reducing atmosphere affects the oxidation state of Fe; (2) dissociation of Fe-Ti interaction may occur during heat treatment.

  6. XPS and ToF-SIMS analysis of natural rubies and sapphires heat-treated in a reducing (5 mol% H 2/Ar) atmosphere

    Science.gov (United States)

    Achiwawanich, S.; James, B. D.; Liesegang, J.

    2008-12-01

    Surface effects on Mong Hsu rubies and Kanchanaburi sapphires after heat treatment in a controlled reducing atmosphere (5 mol% H 2/Ar) have been investigated using advanced surface science techniques including X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Visual appearance of the gemstones is clearly affected by the heat treatment in a reducing atmosphere. Kanchanaburi sapphires, in particular, exhibit Fe-containing precipitates after the heat treatment which have not been observed in previous studies under an inert atmosphere. Significant correlation between changes in visual appearance of the gemstones and variations in surface concentration of trace elements, especially Ti and Fe are observed. The XPS and ToF-SIMS results suggest that; (1) a reducing atmosphere affects the oxidation state of Fe; (2) dissociation of Fe-Ti interaction may occur during heat treatment.

  7. XPS and ToF-SIMS analysis of natural rubies and sapphires heat-treated in a reducing (5 mol% H{sub 2}/Ar) atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Achiwawanich, S. [Department of Physics, La Trobe University, VIC 3086 (Australia); Centre for Materials and Surface Science, La Trobe University, VIC 3086 (Australia); James, B.D. [Centre for Materials and Surface Science, La Trobe University, VIC 3086 (Australia); Department of Chemistry, La Trobe University, VIC 3086 (Australia); Liesegang, J. [Department of Physics, La Trobe University, VIC 3086 (Australia); Centre for Materials and Surface Science, La Trobe University, VIC 3086 (Australia)], E-mail: J.Liesegang@latrobe.edu.au

    2008-12-30

    Surface effects on Mong Hsu rubies and Kanchanaburi sapphires after heat treatment in a controlled reducing atmosphere (5 mol% H{sub 2}/Ar) have been investigated using advanced surface science techniques including X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Visual appearance of the gemstones is clearly affected by the heat treatment in a reducing atmosphere. Kanchanaburi sapphires, in particular, exhibit Fe-containing precipitates after the heat treatment which have not been observed in previous studies under an inert atmosphere. Significant correlation between changes in visual appearance of the gemstones and variations in surface concentration of trace elements, especially Ti and Fe are observed. The XPS and ToF-SIMS results suggest that; (1) a reducing atmosphere affects the oxidation state of Fe; (2) dissociation of Fe-Ti interaction may occur during heat treatment.

  8. Characterization of SiC in DLC/a-Si films prepared by pulsed filtered cathodic arc using Raman spectroscopy and XPS

    International Nuclear Information System (INIS)

    Srisang, C.; Asanithi, P.; Siangchaew, K.; Pokaipisit, A.; Limsuwan, P.

    2012-01-01

    DLC/a-Si films were deposited on germanium substrates. a-Si film was initially deposited as a seed layer on the substrate using DC magnetron sputtering. DLC film was then deposited on the a-Si layer via a pulsed filtered cathodic arc (PFCA) system. In situ ellipsometry was used to monitor the thicknesses of the growth films, allowing a precise control over the a-Si and DLC thicknesses of 6 and 9 nm, respectively. It was found that carbon atoms implanting on a-Si layer act not only as a carbon source for DLC formation, but also as a source for SiC formation. The Raman peak positions at 796 cm -1 and 972 cm -1 corresponded to the LO and TO phonon modes of SiC, respectively, were observed. The results were also confirmed using TEM, XPS binding energy and XPS depth profile analysis.

  9. Quantification of the toxic hexavalent chromium content in an organic matrix by X-ray photoelectron spectroscopy (XPS) and ultra-low-angle microtomy (ULAM)

    Energy Technology Data Exchange (ETDEWEB)

    Greunz, Theresia, E-mail: theresia.greunz@jku.at [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterisation (CDL-MS-MACH), Center for Surface and Nanoanalytics (ZONA), Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Duchaczek, Hubert; Sagl, Raffaela [voestalpine Stahl GmbH, voestalpine-Straße 3, 4031 Linz (Austria); Duchoslav, Jiri; Steinberger, Roland [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterisation (CDL-MS-MACH), Center for Surface and Nanoanalytics (ZONA), Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Strauß, Bernhard [voestalpine Stahl GmbH, voestalpine-Straße 3, 4031 Linz (Austria); Stifter, David [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterisation (CDL-MS-MACH), Center for Surface and Nanoanalytics (ZONA), Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria)

    2017-02-28

    Highlights: • Common methods are not suitable for a reliable determination of Cr(VI) in organic coatings on steel. • Our proposed method is a combination of XPS and ultra-low-angle microtomy (ULAM). • The results allow referring to legal regulations of the Cr(VI) concentration. • For this method no accurate sample parameters are required. - Abstract: Cr(VI) is known for its corrosion inhibitive properties and is, despite legal regulations, still a potential candidate to be added to thin (1–3 μm) protective coatings applied on, e.g., electrical steel as used for transformers, etc. However, Cr(VI) is harmful to the environment and to the human health. Hence, a reliable quantification of it is of decisive interest. Commonly, an alkaline extraction with a photometric endpoint detection of Cr(VI) is used for such material systems. However, this procedure requires an accurate knowledge on sample parameters such as dry film thickness and coating density that are occasionally associated with significant experimental errors. We present a comprehensive study of a coating system with a defined Cr(VI) pigment concentration applied on electrical steel. X-ray photoelectron spectroscopy (XPS) was employed to resolve the elemental chromium concentration and the chemical state. Turning to the fact that XPS is extremely surface sensitive (<10 nm) and that the lowest commonly achievable lateral resolution is a number of times higher than the coating thickness (∼2 μm), a bulk analysis was achieved with XPS line scans on extended wedge-shaped tapers through the coating. For that purpose a special sample preparation step performed on an ultra-microtome was required prior to analysis. Since a temperature increase leads to a reduction of Cr(VI) we extend our method on samples, which were subjected to different curing temperatures. We show that our proposed approach now allows to determine the elemental and Cr(VI) concentration and distribution inside the coating.

  10. Quantification of variable functional-group densities of mixed-silane monolayers on surfaces via a dual-mode fluorescence and XPS label.

    Science.gov (United States)

    Fischer, Tobias; Dietrich, Paul M; Streeck, Cornelia; Ray, Santanu; Nutsch, Andreas; Shard, Alex; Beckhoff, Burkhard; Unger, Wolfgang E S; Rurack, Knut

    2015-03-03

    The preparation of aminated monolayers with a controlled density of functional groups on silica surfaces through a simple vapor deposition process employing different ratios of two suitable monoalkoxysilanes, (3-aminopropyl)diisopropylethoxysilane (APDIPES) and (3-cyanopropyl)dimethylmethoxysilane (CPDMMS), and advances in the reliable quantification of such tailored surfaces are presented here. The one-step codeposition process was carried out with binary silane mixtures, rendering possible the control over a wide range of densities in a single step. In particular, APDIPES constitutes the functional silane and CPDMMS the inert component. The procedure requires only small amounts of silanes, several ratios can be produced in a single batch, the deposition can be carried out within a few hours and a dry atmosphere can easily be employed, limiting self-condensation of the silanes. Characterization of the ratio of silanes actually bound to the surface can then be performed in a facile manner through contact angle measurements using the Cassie equation. The reliable estimation of the number of surface functional groups was approached with a dual-mode BODIPY-type fluorescence label, which allows quantification by fluorescence and XPS on one and the same sample. We found that fluorescence and XPS signals correlate over at least 1 order of magnitude, allowing for a direct linking of quantitative fluorescence analysis to XPS quantification. Employment of synchrotron-based methods (XPS; reference-free total reflection X-ray fluorescence, TXRF) made the traceable quantification of surface functional groups possible, providing an absolute reference for quantitative fluorescence measurements through a traceable measurement chain.

  11. Ptose palpebral causada por Paquidermoperiostose

    Directory of Open Access Journals (Sweden)

    Patricia Regina de Pinho Tavares

    2014-08-01

    Full Text Available A paquidermoperiostose é uma síndrome caracterizada por acometimento cutâneo e ósseo, e em alguns casos ocorre comprometimento palpebral leve. É uma síndrome rara, idiopática ou hereditária, com provável herança autossômica dominante de penetrância variável. Descreve-se o caso de um paciente com ptose grave por paquidermoperiostose elucidando sua fisiopatologia e conduta cirúrgica aplicada.

  12. Mortalidad intrahospitalaria por accidente cerebrovascular

    OpenAIRE

    Federico Rodríguez Lucci; Virginia Pujol Lereis; Sebastián Ameriso; Guillermo Povedano; María F. Díaz; Alejandro Hlavnicka; Néstor A. Wainsztein; Sebastián F. Ameriso

    2013-01-01

    La mortalidad global por accidente cerebrovascular (ACV) ha disminuido en las últimas tres décadas, probablemente debido a un mejor control de los factores de riesgo vascular. La mortalidad hospitalaria por ACV ha sido tradicionalmente estimada entre 6 y 14% en la mayoría de las series comunicadas. Sin embargo, los datos de ensayos clínicos recientes sugieren que esta cifra sería sustancialmente menor. Se revisaron datos de pacientes internados con diagnóstico de ACV del Banco de Datos de Str...

  13. Colecistitis aguda por Streptococcus constellatus

    Directory of Open Access Journals (Sweden)

    M Sandra Gómez-Canosa

    2016-03-01

    Full Text Available Presentamos el caso de una paciente de edad avanzada y significativa comorbilidad que se diagnosticó de colecistitis aguda por Streptococcus constellatus. El drenaje de la vesícula biliar por colecistostomía percutánea, asociado a penicilinas, ha conseguido una evolución favorable. We report the case of a patient of advanced age and significant comorbidity diagnosed acute cholecystitis by Streptococcus constellatus. Gallbladder drainage by percutaneous cholecystostomy associated with penicillins has achieved a favorable outcome.

  14. Endocarditis infecciosa por Paecilomyces variotii

    Directory of Open Access Journals (Sweden)

    Juan Manuel Senior

    2009-06-01

    Full Text Available La endocarditis infecciosa por hongos es una complicación cada vez más frecuente en el mundo. Presentamos un caso de endocarditis infecciosa por Paecilomyces variotii en un paciente de sexo masculino con bioprótesis mitral, que respondió satisfactoriamente al tratamiento con cirugía de reemplazo valvular mitral y anfotericina B (dosis total de 3.670 mg. Hasta la fecha, sólo se han reportado seis casos similares en el mundo, con una mortalidad del 100%.

  15. Temperature-dependent growth and XPS of Ag-doped ZnTe thin films deposited by close space sublimation method

    Energy Technology Data Exchange (ETDEWEB)

    Potlog, Tamara, E-mail: tpotlog@gmail.com [Department of Physics and Engineering, Moldova State University, MD 2009 Chisinau, Republic of Moldova (Moldova, Republic of); Duca, Dumitru [Department of Physics and Engineering, Moldova State University, MD 2009 Chisinau, Republic of Moldova (Moldova, Republic of); Dobromir, Marius [Faculty of Physics, Alexandru Ioan Cuza University, 11 Carol I Blvd., Iasi 700506 (Romania)

    2015-10-15

    Highlights: • Close space sublimation was used for deposition of ZnTe thin films at different substrate temperatures. • Crystallinity is improved evidently with increasing the substrate temperatures. • XPS analysis of Ag-doped ZnTe films by immersion proved the presence of Ag and revealed the increase of the Ag composition with the increasing of the thickness of ZnTe films. - Abstract: Zinc telluride (ZnTe) thin films were sublimated on a glass substrate using closed space sublimation (CSS) technique. The influence of the substrate temperature on the physical properties is studied. The deposited films were immersed in AgNO{sub 3} solution with different concentrations, and then annealed in air. The structure and composition are studied using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). X-ray diffraction patterns of as-deposited ZnTe thin films exhibited polycrystalline behavior. The preferred orientation of (1 1 1) having cubic phase irrespective of the substrate temperature was observed. The XPS analysis confirmed the presence of Ag in the ZnTe thin films after doping by immersion in the AgNO{sub 3} solution of different concentrations.

  16. Determining shell thicknesses in stabilised CdSe@ZnS core-shell nanoparticles by quantitative XPS analysis using an Infinitesimal Columns model

    Energy Technology Data Exchange (ETDEWEB)

    Kalbe, H., E-mail: henryk.kalbe@gmail.com; Rades, S.; Unger, W.E.S.

    2016-10-15

    Highlights: • A novel method to calculate shell thicknesses of core-shell nanoparticles from XPS data is presented. • The approach is widely applicable and combines advantages of existing models. • CdSe@ZnS quantum dots with additional organic stabiliser shell are analysed by XPS. • ZnS and organic shell thicknesses were calculated. • Potential as well as challenges of this and similar approaches are demonstrated. - Abstract: A novel Infinitesimal Columns (IC) simulation model is introduced in this study for the quantitative analysis of core-shell nanoparticles (CSNP) by means of XPS, which combines the advantages of existing approaches. The IC model is applied to stabilised Lumidot™ CdSe/ZnS 610 CSNP for an extensive investigation of their internal structure, i.e. calculation of the two shell thicknesses (ZnS and stabiliser) and exploration of deviations from the idealised CSNP composition. The observed discrepancies between different model calculations can be attributed to the presence of excess stabiliser as well as synthesis residues, demonstrating the necessity of sophisticated purification methods. An excellent agreement is found in the comparison of the IC model with established models from the existing literature, the Shard model and the software SESSA.

  17. Co-ordination properties of diglycol-amide (DGA) to trivalent curium and lanthanides studied by XAS, XRD and XPS methods

    International Nuclear Information System (INIS)

    Yaita, T.; Hirata, M.; Narita, H.; Tachimori, S.; Yamamoto, H.; Edelstein, N.M.; Bucher, J.J.; Shuh, D.K.; Rao, L.

    2001-01-01

    Co-ordination properties of diglycol-amide (DGA) to trivalent curium and to the trivalent lanthanides were studied by the EXAFS, the XRD and the XPS methods. The structural determinations by both the crystal XRD and the solution EXAFS methods showed that the DGA co-ordinated to the trivalent lanthanide ion in a tridentate fashion: co-ordination of three oxygen atoms of each ligand to the metal ion. The bond distances of Er-O (carbonyl) and Er-O (ether) in the Er-DGA complex were 2.35 Angstrom, and 2.46 Angstrom, respectively, while the atom distances of Cm-O (carbonyl) and Cm-O (ether) in the Cm-DGA complex were 2.42 Angstrom and 3.94 Angstrom, respectively from the EXAFS data for the Cm-DGA complex. Accordingly, the DGA would behave only as a semi-tridentate in the co-ordination to trivalent curium in solution. We determined the valence band structures of the Er-DGA complex by the XPS in order to clarify the bond properties of the complex, and assigned the XPS spectrum by using the DV-DS molecular orbital calculation method. (authors)

  18. Consanguinidad por isonimia en Salta

    Directory of Open Access Journals (Sweden)

    Albeza, María V.

    2007-01-01

    Full Text Available Se estimó el coeficiente de parentesco por isonimia para localidades de la Puna, Valle Calchaquí y Valle de Lerma, a fin de evaluar diferentes factores evolutivos que podrían estar afectando la composición genética de la población. A partir de los apellidos de las parejas consignadas en fuentes primarias de información, se estimó la isonimia conyugal o marital, el coeficiente total Ft y sus componentes Fr (inbreeding azaroso y Fn (inbreeding no azaroso. De las localidades estudiadas, en la Puna se ha detectado sólo una pareja isónima en una de ellas, en el Valle Calchaquí, tres y ninguna en el Valle de Lerma. Tanto en el Valle Calchaquí como en el de Lerma, se han estimado valores negativos de Ft, y en la Puna se registran los valores más elevados. En las localidades estudiadas no se cumple el supuesto de transmisión patrilineal de apellidos por lo que los valores de Fr y por ende de Ft podrían estar subestimados. Es por ello que sería necesario contar con información desde otras vertientes metodológicas para corroborar, complementar y manejar cuidadosamente el análisis de los datos y las conclusiones que se obtienen.

  19. Celulitis por citomegalovirus Cytomegalovirus cellulitis

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    A. Ruiz Lascano

    2002-12-01

    Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.Cutaneous lesions in CMV infection are rare, often a late manifestation of systemic infection, and usually herald a fatal course. A 70 year-old woman received a kidney transplantation one month before consulting and immunosuppressive therapy that included cyclosporine A and methylprednisone. She complained of fever, local pain in her right leg, and an erythematous and swelling plaque. She was treated with intravenous antibiotics without improvement. A skin biopsy was performed and the tissue obtained was sent for bacterial and fungal cultures as well as for histological examination. Cultures were negative. The biopsy showed CMV cytopathic changes. Immunoperoxidase staining was positive for CMV and polymerase chain reaction (PCR testing revealed CMV DNA. She was treated with ganciclovir with resolution of the lesion. CMV cellulitis is a rare cutaneous manifestation

  20. O amor e o erótico lexicograficamente analisado: uma visão discursiva

    Directory of Open Access Journals (Sweden)

    Zilda Maria Dutra Rocha

    2016-07-01

    Full Text Available The meanings of words from a dictionary, especially when it is a dictionary recognized, gain more importance as the effects of senses, formed from the view of the lexicographer and society. Like others, the love and erotic words express, in addition to shared meaning by members of the same language, the point of view of a society and the author who describes them as entries in his work. We cut out the Aurelio Junior Dictionary (2011 the entries love and erotic, which are described and analyzed from the perspective of Discourse Analysis (ORLANDI, 1999, 2000; MACHADO, 2009 and the theoretical perspective of Lexicography Discourse (NEVES, 1996; PONTES, 2009, the field of lexicography whose research focus discourses produced by the dictionary. The lexicographical research under a discursive vision sees in the words of a speech beyond the speech itself. That said we justify our work as important because it is the discourse produced in facing dictionary for elementary school students, these speeches, usually taken as ideologically neutral by common consultant. To form our conclusions we ask: Witch interpretations is the student able to take from the effects of meanings generated by the meanings shown in these entries.

  1. Leitura de histórias e evocação de estados mentais por pré-escolares

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    Marisa Cosenza Rodrigues

    Full Text Available Esta pesquisa visou investigar a evocação de termos mentais por pré-escolares de 5 e 6 anos na leitura de um livro infantil nacional contendo narrativa por imagem (Truks - Editora Ática. Os relatos individuais das crianças, selecionadas por faixa etária, foram gravados, transcritos e analisados identificando-se palavras e expressões voltadas para os estados mentais mediante 4 categorias: termos cognitivos, emocionais, de desejo/intenção e perceptivos. Os resultados indicaram que as crianças de ambas as idades utilizaram termos referentes a estados mentais na leitura de narrativa por imagem. Os termos mais evocados foram os perceptivos, seguidos dos emocionais, cognitivos e de desejo/intenção. Houve diferença significativa entre o número total de termos evocados pelas crianças de 6 anos (264 e as de 5 anos (183. A predominância de termos perceptivos indica que as crianças focalizaram em suas narrativas mais termos que denotam comportamentos físicos e ações das personagens do que propriamente estados subjetivos.

  2. Cotidiano da gravidez de risco por cardiopatia: estudo fenomenológico das relações assistenciais

    Directory of Open Access Journals (Sweden)

    Thaís Vasconselos Amorim

    Full Text Available RESUMO Objetivo: Desvelar o cotidiano das relações assistenciais do ser-aí-mulher na gravidez de alto risco por doença cardíaca. Métodos: Pesquisa qualitativa fenomenológica. Dezessete participantes foram entrevistadas em instituição referência para risco materno e os significados expressos foram analisados à luz do pensamento de Martin Heidegger. Resultados: As mulheres significaram terem sido cobradas pelos médicos por engravidarem e; saberem que o cardiologista dá o parecer, mas o obstetra é quem vai decidir a via de parto. Conclusão: Evidenciaram-se relações assistenciais pautadas na ótica fisiopatológica de acompanhamento gestacional e invisibilidade da equipe de enfermagem junto à gestante. Se por um lado os resultados apontam a necessidade de transcender para uma relação existencial que considera a mulher como ser-aí dotada de possibilidades, por outro anuncia a importância do cuidado de enfermagem congruente às necessidades de gestantes portadoras de cardiopatia na perspectiva de se fazer percebido e anunciado pelo ser-cuidado.

  3. Se los por se lo

    Directory of Open Access Journals (Sweden)

    José Luis Rivarola

    1985-12-01

    Full Text Available El sistema de la conjugación "objetiva" plantea interesantesproblemas que fueron tratados en parte por K. Heger (1966 en suestudio comparativo del francés y del español. De la comparaciónse desprende, por ejemplo, que en español hay un cierto número deambigüedades que no permiten establecer un "paradigma tan completo y unívoco" como en el caso del francés. Dentro de estas ambigüedades se encuentran las que propicia el gramema se: "El morfema [gramema] se funciona no sólo como pronombre reflexivo, sinotambién como variante combinatoria del pronombre personal complemento indirecto de la tercera persona.

  4. Esporotricosis diagnosticada por el laboratorio

    OpenAIRE

    Nelly Ordóñez; Jeannette Castillo; Elizabeth Castañeda

    1989-01-01

    De 1976 a 1989 se han diagnosticado 40 casos de esporotricosis en el laboratorio de Micología del Instituto Nacional de Salud. La enfermedad se presentó en pacientes entre 4 y 52 años y tuvo predilección por el sexo masculino: 35 de 40 (87,5%; las formas clínicas más frecuentes fueron la cutánea fija, 18 de 40 (45%), y la linfocutánea, 17 de 40 (42,5%), con localización mayor en miembros superiores, 18 de 40 (45%). El diagnóstico se estableció por el aislamiento del Sporothrix schenckii en 35...

  5. Esporotricosis diagnosticada por el laboratorio

    Directory of Open Access Journals (Sweden)

    Nelly Ordóñez

    1989-06-01

    Full Text Available De 1976 a 1989 se han diagnosticado 40 casos de esporotricosis en el laboratorio de Micología del Instituto Nacional de Salud. La enfermedad se presentó en pacientes entre 4 y 52 años y tuvo predilección por el sexo masculino: 35 de 40 (87,5%; las formas clínicas más frecuentes fueron la cutánea fija, 18 de 40 (45%, y la linfocutánea, 17 de 40 (42,5%, con localización mayor en miembros superiores, 18 de 40 (45%. El diagnóstico se estableció por el aislamiento del Sporothrix schenckii en 35 de 38 pacientes (92%; los otros dos pacientes se diagnosticaron empleando otras técnicas: inmunofluorescencia directa, intradermorreacción y aglutinación en tubo.

  6. Miasis cutanea por cordylobia anthropophaga

    Directory of Open Access Journals (Sweden)

    Alkorta Gurrutxaga Miriam

    2001-01-01

    Full Text Available El incremento progresivo en el número de personas que viajan a países tropicales ha hecho que las enfermedades importadas adquieran una relevancia cada vez mayor. Las miasis (o infestaciones por larvas de moscas cutáneas se encuentran entre este tipo de enfermedades siendo especialmente frecuentes en países tropicales. A propósito de la observación de un caso de miasis cutánea masiva por Cordylobia antropophaga, que ocurrió en una mujer de 34 años de edad al volver de un viaje a Senegal, se ha efectuado una revisión de los casos de miasis cutáneas forunculoides importadas publicados en España, así como de la biología, patología, tratamiento y prevención de la miasis humana por Cordylobia anthropophaga. El caso referido, se caracterizó por la infestación con un número inusualmente elevado de larvas, no sospechándose su etiología hasta la fase final de la enfermedad. La emergencia continuada de larvas (se recogieron 91 generó en la paciente un estado de ansiedad importante. Finalmente, la eliminación de las larvas provocó una rápida mejoría de la paciente. Aunque los casos de miasis cutánea no tienen la gravedad de otras enfermedades importadas, su conocimiento es necesario desde el punto de vista preventivo, diagnóstico y terapeútico. Es importante proceder a la identificación morfológica de las larvas diferenciándolas de otro tipo de miasis con implicaciones terapéuticas diferentes.

  7. Efectos de fotodegradación propiciados por recubrimientos de TiO2 y TiO2-SiO2 obtenidos por Sol-Gel

    Directory of Open Access Journals (Sweden)

    Rodriguez Paez, J. E.

    2008-10-01

    Full Text Available Photodegradation effect is widely used for water purification this contributes to preservation and protection of environment. Titanium oxide, (TiO2, is a compound that shows up this phenomenon. TiO2 is a semiconductor which may degradate pollutants through of a oxidation process. It permit the treatment of the residual water. It this work we has conformed coatings of TiO2 y TiO2-SiO2, utilized Sol-Gel method and investigated the degradation of the blue Methylene. For this, we introduced these coatings in the blue methylene solution which was illuminated with radiation of λ=365nm to activate its photocatilist properties. The structures of the coatings were characterized using Atomic Force Microscopy (AFM and X-ray Photoelectron Spectroscopy (XPS.El efecto de fotodegradación es ampliamente utilizado para la purificación del agua, acción que contribuye a la conservación y protección del medio ambiente; el óxido de titanio (TiO2 es uno de los semiconductores que pueden degradar contaminantes mediante procesos de oxidación, lo que lo hace apto para el tratamiento de aguas residuales. En este trabajo se conformaron recubrimientos de TiO2 y TiO2-SiO2, por el método Sol-Gel, y se estudio la degradación que experimentaba una solución de azul de metileno al introducirle estos recubrimientos e iluminarlos con una radiación de λ=365nm para activar su propiedad fotocatalítica. Los recubrimientos fueron caracterizados microestructuralmente utilizando Microscopía de Fuerza Atómica (MFA y Espectroscopía de Fotoelectrones de rayos X (XPS. Los resultados obtenidos de los ensayos de fotodegradación indican que los recubrimientos con una cantidad pequeña de silicio presentan un mayor efecto de fotodegradación indicando que el silicio puede generar puntos de anclaje que facilitan las reacciones de fotocatálisis. Por otro lado, la formación de centros activos, constituidos principalmente por carbono, también contribuyeron al desarrollo de estas

  8. De um escritor escrevente: “O amor de Pedro por João”

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    Maria Iraci Cardoso Tuzzin

    2017-03-01

    Full Text Available O romance O amor de Pedro por João publicado no Brasil, em 1982, e escrito durante o exílio do escritor brasileiro Tabajara Ruas (1942 é analisado a partir da relação escritor/escrita. Tal correspondência é discutida por um viés que inclui as anotações de pesquisadores, como Avelar, Silverman e Santiago, entre outros. A observação da forma, do estilo e das temáticas empregadas pelo artista aponta para a complexidade de questões referentes à profissão “escritor” em um contexto histórico pleno de cerceamento de liberdades situado entre os anos 1960 e 1980. Além disso, suscita reflexões sobre procedimentos literários experimentais em um meio social em que se ampliaram o grau e o controle da informação, apontando, deste modo, ligações entre a Literatura e a História.

  9. Abdome agudo por obstrução por ileobiliar

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    Márcia Cristina de Alencastro

    Full Text Available OBJETIVO: descrever a experiência na abordagem dos doentes com abdome agudo por obstrução por IB, desde o diagnóstico até o tratamento definitivo. MÉTODOS: estudo retrospectivo incluindo todos os casos de IB tratados em um período de 23 anos. De acordo com a abordagem cirúrgica realizada, os pacientes foram divididos em dois grupos (1 enterolitotomia com colecistectomia no segundo momento; e (2 enterolitotomia, colecistectomia e abordagem da fístula. RESULTADOS: Doze pacientes foram incluídos, sendo 11 mulheres (91,6%, com média de idade de 72,2 anos. Todos os pacientes apresentavam doenças associadas, principalmente hipertensão arterial sistêmica (75%. Dois pacientes não apresentavam sintomas significativos de obstrução intestinal. O diagnóstico de IB foi realizado em seis pacientes (50% antes da laparotomia. O grupo 1 foi constituído de oito pacientes e o grupo 2 de quatro, e a morbidade foi, respectivamente, 33,3% e 8,3%. A mortalidade foi 16,6% (um paciente de cada grupo. CONCLUSÃO: O manejo do IB deve ser individualizado. O tratamento da obstrução mediante remoção do cálculo biliar por enterotomia proximal é a escolha inicial para o tratamento do IB. A colecistectomia e a correção da fístula bilioentérica podem ser realizadas juntamente com a remoção do cálculo, no entanto, em pacientes com comorbidades significativas, esses procedimentos devem ser realizados posteriormente.

  10. Mortalidad por meningitis por Pasteurella canis. Oportunidades de aprendizaje

    OpenAIRE

    Ana Rosa Ropero Vera; Jorge Martín Rodríguez; Guillermo Farfán

    2016-01-01

    La meningitis bacteriana es una enfermedad importante de distribución mundial, causa mayor y sustancial de mortalidad y morbilidad en países en desarrollo. La Organización Mundial de la Salud (OMS) sostiene que la meningitis es una de las diez afecciones principales del ser humano y debe ser considerada como una emergencia infectológica; por eso es fundamental reconocer que esta enfermedad es causa de muerte en niños de todo el mundo, sin distinción de raza, nivel económico o sociocultural. S...

  11. Uso de medicamentos por pessoas com deficiências em áreas do estado de São Paulo

    OpenAIRE

    Castro, Shamyr Sulyvan; Pelicioni, Americo Focesi; Cesar, Chester Luiz Galvão; Carandina, Luana; Barros, Marilisa Berti de Azevedo; Alves, Maria Cecilia Goi Porto; Goldbaum, Moisés

    2010-01-01

    OBJETIVO: Analisar o consumo de medicamentos e os principais grupos terapêuticos consumidos por pessoas com deficiências físicas, auditivas ou visuais. MÉTODOS: Estudo transversal em que foram analisados dados do Inquérito Multicêntrico de Saúde no Estado de São Paulo (ISA-SP) em 2002 e do Inquérito de Saúde no Município de São Paulo (ISA-Capital), realizado em 2003. Os entrevistados que referiram deficiências foram estudados segundo as variáveis que compõem o banco de dados: área, sexo, rend...

  12. Por entre as linhas: imaginário, saberes e fazeres docente = Between the lines: imagination, knowledge and teachers practices

    OpenAIRE

    Voos, Jordelina Beatriz Anacleto

    2014-01-01

    Este artigo trata de uma experiência, na prática de pesquisa em educação sobre o exercício de reflexão de um professor de educação física, referente à sua prática, mediante o registro de atividades. À luz dos procedimentos da Análise de Conteúdo, referencial construído por Bardin (2002), foram analisados os textos de oito diários de classe. Emergiram muitos elementos sobre a prática do professor, dentre eles, destacou-se o significado do espaço físico escolar e a relação, desse espaço, com os...

  13. Bonding and XPS chemical shifts in ZrSiO4 versus SiO2 and ZrO2: Charge transfer and electrostatic effects

    International Nuclear Information System (INIS)

    Guittet, M.J.; Gautier-Soyer, M.; Crocombette, J.P.

    2001-01-01

    The degree of ionic/covalent character in oxides has a great influence on the electronic structure and the material's properties. A simple phenomenological rule is currently used to predict the evolution of covalence/ionicity in mixed oxides compared to the parent ones, and is also widely used to interpret the x-ray photoelectron spectroscopy (XPS) binding-energy shifts of the cations in terms of charge transfer. We test the validity of this simple rule and its application to XPS of mixed oxides with a prototypical system: zircon ZrSiO 4 and parent oxides ZrO 2 and SiO 2 . The ionic charges on Si, Zr, and O were extracted from the density functional theory in the local density approximation calculations in the plane-wave formalism. In agreement with the predictions of the phenomenological rule, the most ionic cation (Zr) becomes more ionic in ZrSiO 4 than in ZrO 2 , while the more covalent one (Si) experiences a corresponding increase in covalence with respect to SiO 2 . The XPS chemical shifts of the O 1s, Si 2p, and Zr 3d 5/2 photoelectron lines in the three oxides were measured and the respective contributions of charge transfer and electrostatic effects (initial state), as well as extra-atomic relaxation effects (final state) evaluated. The validity of the phenomenological rule of mixed oxides used in x-ray electron spectroscopy as well as the opportunity to use the O1s binding-energy shifts to derive a scale of covalence in silicates is discussed

  14. Desajuste educativo por regiones en Colombia: ¿competencia por salarios o por puestos de trabajo?

    Directory of Open Access Journals (Sweden)

    Castillo Caicedo Maribel

    2007-08-01

    Full Text Available Este trabajo aporta una perspectiva del fenómeno de la sobreeducación,
    entendida como un desajuste por exceso, entre el nivel educativo alcanzado
    por el individuo y el exigido por el puesto de trabajo en el cual se
    desempeña; esto se debe a que existe una demanda laboral estrecha de
    puestos de trabajo para personas calificadas en Colombia. Se analizan las
    contribuciones empíricas existentes y el debate sobre las mismas; se
    examinan las teorías que permiten explicar la existencia de un desajuste
    educativo y se realiza una revisión de la literatura internacional y
    nacional sobre el tema. Adicionalmente, se plantean una serie de hipótesis
    para desarrollar un esquema que permita determinar el comportamiento
    del individuo en el fenómeno de la sobreeducación.

  15. Microstructure and electrical properties of slug-type resistors based on B4C and TiC - ESCA - XPS and impedance spectroscopy investigations

    International Nuclear Information System (INIS)

    Klimiec, E.; Zaraska, W.; Stobiecki, T.; Bak, W.; Starzyk, F.

    2000-01-01

    The microstructure and electrical properties of slug-type resistors based on B 4 C and TiC were investigated. From XPS measurements was deducted that Ti in TiO 2 is in intermediate oxidation number between Ti +4 and Ti +3 . The impedance of both type of resistors is independent on frequency in the range from 10 3 to 10 4 Hz, only very subtle differences above 10 4 Hz are observed. The metallic type conductivity in TiC and semiconducting in B 4 C was established. (author)

  16. Utilization of the statistics techniques for the analysis of the XPS (X-ray photoelectron spectroscopy) and Auger electronic spectra's deconvolutions

    International Nuclear Information System (INIS)

    Puentes, M.B.

    1987-01-01

    For the analysis of the XPS (X-ray photoelectron spectroscopy) and Auger spectra, it is important to performe the peaks' separation and estimate its intensity. For this purpose, a methodology was implemented, including: a spectrum's filter; b) substraction of the base line (or inelastic background); c) deconvolution (separation of the distribution that integrates the spectrum) and d) error of calculation of the mean estimation, comprising adjustment quality tests. A software (FORTRAN IV plus) that permits to use the methodology proposed from the experimental spectra was implemented. The quality of the methodology was tested with simulated spectra. (Author) [es

  17. Muerte materna por malaria grave por Plasmodium vivax

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    Nancy Arróspide

    Full Text Available Se presenta el caso de una mujer de 19 años con 29 semanas de gestación, procedente de Llumpe (Ancash con antecedentes de viajes a las localidades de Chanchamayo (Junín y Rinconada (Ancash. Ingresó al Hospital de Chacas (Ancash por presentar mal estado general, deshidratación, dificultad respiratoria, ictericia, sensación de alza térmica y dolor abdominal, tuvo reporte de: hemoparásitos 60% en frotis sanguíneo. Fue transferida al Hospital Ramos Guardia (Huaraz donde presentó mayor dificultad respiratoria, coluria, hematuria, disminución del débito urinario y reporte de Plasmodium (+, luego fue transferida al Hospital Cayetano Heredia (Lima donde ingresó a la Unidad de Cuidados Intensivos (UCI, con evolución a falla multiorgánica, óbito fetal y muerte materna. Se confirmó infección por Plasmodium vivax. Destacamos la importancia de mejorar nuestras capacidades de diagnóstico y manejo para brindar un tratamiento adecuado y oportuno.

  18. Penfigoide ampolloso inducido por vildagliptina

    OpenAIRE

    Geraldine López-Sánchez; Eduardo Reyna-Villasmil

    2016-01-01

    Penfigoide ampolloso (PA) es una enfermedad crónica, poco común, autoinmune y sub-epidérmica. La etiología no es completamente comprendida. Puede estar asociado con fármacos, radiación ultravioleta y exposición de rayos X. Hay algunos informes sobre la PA inducidos por gliptinas (vildagliptina, sitagliptina, saxagliptina) o inhibidores de la dipeptidil peptidasa IV (DPP-IV). La enzima DPP-IV degrada péptido similar al glucagón 1, que es u...

  19. Clonagem de canistel por estaquia

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    Fernando Marcelo Chiamolera

    2014-09-01

    Full Text Available O canistel é nativo do sul do México e América Central e seus frutos apresentam elevado teor de carotenoides e vitamina A. Sua propagação é feita via sementes, resultando em considerável variabilidade genética entre os indivíduos, sendo a propagação vegetativa preferível, a fim de fixar características desejáveis. Assim, o objetivo deste trabalho foi avaliar a propagação vegetativa por estaquia de ramos semi-herbáceos de canistel, em função de quatro genótipos e quatro concentrações de AIB. Foram utilizadas estacas semiherbáceas apicais, mantidas com um par de folhas, sob nebulização intermitente, por 120 dias. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 4×4 (genótipos de canistel × concentrações de AIB, com quatro repetições e dez estacas por parcela. Foram avaliados a porcentagem de sobrevivência, a retenção foliar, o enraizamento, o calejamento, o número e o comprimento médio de raízes por estaca. O genótipo PC-1 foi superior aos demais, em todas as variáveis avaliadas, com destaque para o enraizamento das estacas, superior a 60%. As concentrações de AIB (0; 1.000; 3.000 e 5.000 mg L-1 não influenciaram na sobrevivência, retenção foliar e enraizamento das estacas, mas aumentaram o número e o comprimento de raízes em relação ao tratamento-controle (sem AIB. Há diferença na capacidade de enraizamento das estacas entre os genótipos de canistel, sendo a melhor resposta obtida com PC-1. A concentração de 3.000 mg L-1 de AIB resulta em maior número e comprimento de raízes nas estacas de canistel.

  20. Once mil metros por segundo

    OpenAIRE

    2012-01-01

    Esta exposición es una ventana hacia el mundo de la Ciencia Ficción. Los sueños de escritores extraordinarios, personajes, lugares, máquinas y robots que cada día están más cerca de nuestra cotidianidad gracias a los avances de la ciencia y la tecnología hacen parte de la muestra itinerante por las sedes de la Universidad Nacional. El visitante puede recorrer los diferentes géneros que constituyen este género literario, además de conocer sus principales representantes. Así mismo se explor...

  1. Correlação entre os diagnósticos citopatológicos e histopatológicos das lesões da mucosa oral após a punção aspirativa por agulha fina

    OpenAIRE

    Robaina, Tatiana Ferreira; Coutinho, Antonio Carlos de Azeredo; Valladares, Carla Peixoto; Dias, Eliane Pedra; Lourenço, Simone de Queiroz Chaves

    2007-01-01

    OBJETIVO: Fazer um estudo retrospectivo, correlacionando os diagnósticos citopatológicos obtidos por punção aspirativa por agulha fina (PAAF) com os diagnósticos histopatológicos de lesões da região bucomaxilofacial, de pacientes que foram atendidos no Serviço de Cirurgia e Traumatologia Bucomaxilofacial do Hospital Universitário Antonio Pedro/UFF, entre maio de 1999 e maio de 2004. MÉTODO: Foram analisados os laudos cito e histopatológicos emitidos pelo Serviço de Anatomia Patológica (SAP-HU...

  2. La curiosidad por la naturaleza

    Directory of Open Access Journals (Sweden)

    José Vicente Rodríguez

    2016-07-01

    Full Text Available Esta actitud es un instrumento estratégico para estimular procesos de desarrollo realmente sostenibles, donde se aproveche la admiración que nos embarga al conocer y apreciar lo que nos rodea para responsablemente utilizar y conservar nuestros recursos naturales. Con esta reflexión deseo resaltar esa motivación de escudriñar lo desconocido, que fue también la virtud que propició el desarrollo de la personalidad de Francisco José de Caldas y Tenorio, uno de nuestros primeros y connotados sabios colombianos, y en cuyo honor se constituyó la revista de divulgación científica más importante del país, que en estos momentos cumple 76 años de existencia. Caldas tuvo curiosidad por todo lo que existía en su entorno; inicialmente en su natal Popayán, donde se maravilló por lo natural, lo que lo motivó y llevó más allá de su tierra a formar parte de la mayor empresa de exploración científica adelantada en ese entonces en territorio americano: la primera Expedición Botánica al nuevo Reino de Granada, de José Celestino Mutis.

  3. Hipoglucemia inducida por carcinoma adrenal

    Directory of Open Access Journals (Sweden)

    Jimena Soutelo

    2013-08-01

    Full Text Available El carcinoma suprarrenal es una neoplasia maligna infrecuente y de mal pronóstico. La presentación clínica más común es originada por la producción hormonal excesiva, mientras que el desarrollo de hipoglucemia sintomática es excepcional. Presentamos el caso de una mujer de 37 años que ingresó al hospital por síntomas de hipoglucemias graves, hipertensión arterial, hipopotasemia y amenorrea secundaria. En el laboratorio se halló hipoglucemia con insulina inhibida y niveles de andrógenos en rango tumoral. La tomografía computarizada (TC de abdomen y pelvis mostró voluminosa formación heterogénea de aspecto sólido sin plano de clivaje con respecto al parénquima hepático e intenso realce con contraste. Luego de la extirpación de la masa retroperitoneal, evolucionó con valores de glucemia y potasemia normales, estabilizó la presión arterial y recuperó los ciclos menstruales.

  4. Mortalidad por meningitis por Pasteurella canis. Oportunidades de aprendizaje

    Directory of Open Access Journals (Sweden)

    Ana Rosa Ropero Vera

    2016-01-01

    Full Text Available La meningitis bacteriana es una enfermedad importante de distribución mundial, causa mayor y sustancial de mortalidad y morbilidad en países en desarrollo. La Organización Mundial de la Salud (OMS sostiene que la meningitis es una de las diez afecciones principales del ser humano y debe ser considerada como una emergencia infectológica; por eso es fundamental reconocer que esta enfermedad es causa de muerte en niños de todo el mundo, sin distinción de raza, nivel económico o sociocultural. Se realizó una investigación de caso en menor de 53 días de nacido, que cumplía con los criterios clínicos y de laboratorio compatible con meningitis bacteriana, con el propósito de analizar y fortalecer la toma de decisiones en salud pública por parte de la secretaría local de salud del municipio de Valledupar (Colombia. Entre los hallazgos se encontró antecedentes infecciosos en el menor, coloración de Gram y cultivo de LCR, en el que se identificó cocobacilos Gram negativos, que fueron aislados como agente causal Pasteurella canis. Este estudio pretende sensibilizar a los prestadores de salud para que cuenten con personal altamente capacitado para brindar tratamientos adecuados y prevenir complicaciones en la meningitis bacteriana en niños, y así disminuir la posibilidad de secuelas o muerte, tanto en pacientes con compromiso inmunológico o sin este.

  5. Cu(II immobilization onto a one-step synthesized poly(4-vinylpyridine-co-ethylene glycol dimethacrylate resin: Kinetics and XPS analysis

    Directory of Open Access Journals (Sweden)

    Maksin Danijela D.

    2016-01-01

    Full Text Available Synthesis of an unconventional resin based on 4-vinylpyridine (4-VP and its Cu(II sorption behavior were studied. Three samples of macroporous crosslinked poly(4-vinylpyridine-co-ethylene glycol dimethacrylate [P4VPE] with different porosity parameters were prepared by suspension copolymerization by varying the n-heptane amount in the inert component. The samples were characterized by mercury porosimetry, elemental analysis and x-ray photoelectron spectroscopy (XPS. The sorption of P4VPE for Cu(II ions, determined under non-competitive conditions, was relatively rapid, i.e. the maximum capacity was reached within 30 min. The maximum experimental sorption capacity for the sample with the highest values of pore diameter and specific pore volume (Sample 3, Qeq = 89 mg g-1 was 17.5 times higher than for the sample with the lowest values of pore diameter and specific pore volume (Sample 1, Qeq = 5.1 mg g-1. Since the values for pyridine content in all P4VPE samples were almost the same, it was concluded that the porosity parameters have predominant influence on Cu(II sorption rates on P4VPE. The sorption behavior and the rate-controlling mechanisms were analyzed using six kinetic models (pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion, Bangham and Boyd models. XPS study clarified the nature of the formed P4VPE-Cu(II species. [Projekat Ministarstva nauke Republike Srbije, br. TR 37021 i br. III 43009

  6. Comparative EIS and XPS studies of the protective character of thin lacquer films containing CR or P salts formed on galvanised steel, galvanneal and galfan substrates

    Energy Technology Data Exchange (ETDEWEB)

    Feliu, S.; Barranco, V

    2004-03-01

    X-ray photoelectron spectroscopy (XPS) is used to analyse variations during exposure to humidity and UV radiation (UVCON test) in the chemical composition of the outer surface of organic coatings (lacquers) containing phosphating or chromating reagents applied on galvanised steel, galvanneal and galfan substrates. By means of electrochemical impedance spectroscopy (EIS) measurements the protective character of the coatings analysed by XPS is studied and an attempt is made to establish possible relationships between the chemical composition of the surface of the lacquered substrates after exposure to the UVCON test and their electrochemical characterisation in immersion in a 3% NaCl solution. In general, the formation of defects or the loss of adhesion of the lacquer film leads to a significant reduction in charge transfer resistance values and, at the same time, an increase in interfacial capacitance values. The special behaviour of the galfan/lacquer 'with chromating reagents' system is associated with the presence of a thin insulating film of chromium and aluminium oxides at the base of the pores in the lacquer. Interfacial capacitance values tend to evolve in close correspondence with the content of some elements on the surface of the materials.

  7. Influence of a chromium ion implantation on the passive behaviour of nickel in artificial sea-water: An EIS and XPS study

    International Nuclear Information System (INIS)

    Girault, P.; Grosseau-Poussard, J.L.; Dinhut, J.F.; Marechal, L.

    2001-01-01

    The passive behaviour in artificial sea-water of Cr-implanted (4x10 16 ions/cm 2 , 60 keV) and non-implanted Ni was studied at room temperature by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The transfer resistance obtained for the implanted specimen (R t ∼5586 kΩ cm 2 ) is extremely enhanced compared to the corresponding value of the non-implanted Ni (R t ∼94 kΩ cm 2 ) indicating a considerable increase in the protective efficiency of the implanted layer. The EIS spectra of ion-implanted Ni exhibit one capacitance loop while in the non-implanted Ni two distinct loops can be observed. These changes in EIS behaviour by the ion-implantation are related to the increase of the superficial layer density resulting in a more stable passive layer. Equivalent circuits were proposed to fit the impedance spectra and corresponding electrochemical parameters deduced. These findings were compared with the results obtained by analysis of the passive film formed on Ni, performed by XPS, and with previous investigations of similar alloys. It appears that the passive film formed on Ni consists of NiO and Ni(OH) 2 whereas the chromium implantation leads to the formation in the passive state of Cr oxides and hydroxides which are responsible of the large increase of the transfer resistance

  8. XPS and STEM study of the interface formation between ultra-thin Ru and Ir OER catalyst layers and perylene red support whiskers

    Directory of Open Access Journals (Sweden)

    Atanasoska Ljiljana L.

    2013-01-01

    Full Text Available The interface formation between nano-structured perylene red (PR whiskers and oxygen evolution reaction (OER catalysts ruthenium and iridium has been studied systematically by XPS and STEM. The OER catalyst over-layers with thicknesses ranging from ~0.1 to ~50 nm were vapor deposited onto PR ex-situ. STEM images demonstrate that, with increasing thickness, Ru and Ir transform from amorphous clusters to crystalline nanoparticles, which agglomerate with increased over-layer thickness. XPS data show a strong interaction between Ru and PR. Ir also interacts with PR although not to the extent seen for Ru. At low coverages, the entire Ru deposit is in the reacted state while a small portion of the deposited Ir remains metallic. Ru and Ir bonding occur at the PR carbonyl sites as evidenced by the attenuation of carbonyl photoemission and the emergence of new peak assigned to C-O single bond. The curve fitting analysis and the derived stoichiometry indicates the formation of metallo-organic bonds. The co-existence of oxide bonds is also apparent.

  9. The influence of oxygen adsorption on the NEXAFS and core-level XPS spectra of the C{sub 60} derivative PCBM

    Energy Technology Data Exchange (ETDEWEB)

    Brumboiu, Iulia Emilia, E-mail: iulia.brumboiu@physics.uu.se; Eriksson, Olle; Brena, Barbara [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Ericsson, Leif; Hansson, Rickard; Moons, Ellen [Department of Engineering and Physics, Karlstad University, SE-65188 Karlstad (Sweden)

    2015-02-07

    Fullerenes have been a main focus of scientific research since their discovery due to the interesting possible applications in various fields like organic photovoltaics (OPVs). In particular, the derivative [6,6]-phenyl-C{sub 60}-butyric acid methyl ester (PCBM) is currently one of the most popular choices due to its higher solubility in organic solvents compared to unsubstituted C{sub 60}. One of the central issues in the field of OPVs is device stability, since modules undergo deterioration (losses in efficiency, open circuit voltage, and short circuit current) during operation. In the case of fullerenes, several possibilities have been proposed, including dimerization, oxidation, and impurity related deterioration. We have studied by means of density functional theory the possibility of oxygen adsorption on the C{sub 60} molecular moiety of PCBM. The aim is to provide guidelines for near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) measurements which can probe the presence of atomic or molecular oxygen on the fullerene cage. By analysing several configurations of PCBM with one or more adsorbed oxygen atoms, we show that a joint core level XPS and O1s NEXAFS investigation could be effectively used not only to confirm oxygen adsorption but also to pinpoint the bonding configuration and the nature of the adsorbate.

  10. Difference in surface reactions between titanium and zirconium in Hanks' solution to elucidate mechanism of calcium phosphate formation on titanium using XPS and cathodic polarization

    International Nuclear Information System (INIS)

    Tsutsumi, Y.; Nishimura, D.; Doi, H.; Nomura, N.; Hanawa, T.

    2009-01-01

    Titanium and zirconium were immersed in Hanks' solution with and without calcium and phosphate ions, and the surfaces were characterized with X-ray photoelectron spectroscopy (XPS) to determine the mechanism of calcium phosphate formation on titanium in simulated body fluids and in a living body. In addition, they were cathodically polarized in the above solutions. XPS characterization and cathodic polarization revealed differences in the surface properties in the ability of calcium phosphate formation between titanium and zirconium. The surface oxide film on titanium is not completely oxidized and is relatively reactive; that on zirconium is more passive and protective than that on titanium. Neither calcium nor phosphate stably exists alone on titanium, and calcium phosphate is naturally formed on it; calcium phosphate formed on titanium is stable and protective. On the other hand, calcium is never incorporated on zirconium, while zirconium phosphate, which is easily formed on zirconium, is highly stable and protective. Our study presents new information regarding the surface property of titanium and demonstrates that the characteristics of titanium and zirconium may be applied to various medical devices and new surface modification techniques.

  11. Monitoring N3 dye adsorption and desorption on TiO2 surfaces: a combined QCM-D and XPS study.

    Science.gov (United States)

    Wayment-Steele, Hannah K; Johnson, Lewis E; Tian, Fangyuan; Dixon, Matthew C; Benz, Lauren; Johal, Malkiat S

    2014-06-25

    Understanding the kinetics of dye adsorption and desorption on semiconductors is crucial for optimizing the performance of dye-sensitized solar cells (DSSCs). Quartz crystal microbalance with dissipation monitoring (QCM-D) measures adsorbed mass in real time, allowing determination of binding kinetics. In this work, we characterize adsorption of the common RuBipy dye N3 to the native oxide layer of a planar, sputter-coated titanium surface, simulating the TiO2 substrate of a DSSC. We report adsorption equilibrium constants consistent with prior optical measurements of N3 adsorption. Dye binding and surface integrity were also verified by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy (XPS). We further study desorption of the dye from the native oxide layer on the QCM sensors using tetrabutylammonium hydroxide (TBAOH), a commonly used industrial desorbant. We find that using TBAOH as a desorbant does not fully regenerate the surface, though little ruthenium or nitrogen is observed by XPS after desorption, suggesting that carboxyl moieties of N3 remain bound. We demonstrate the native oxide layer of a titanium sensor as a valid and readily available planar TiO2 morphology to study dye adsorption and desorption and begin to investigate the mechanism of dye desorption in DSSCs, a system that requires further study.

  12. La administración por objetivos

    OpenAIRE

    García Madariaga, Ricardo

    1988-01-01

    De la administración por objetivos puede esperarse dos clases de resultados diferentes pero complementarios. Por una parte, la administración por objetivos contribuye a crear o mantener las condiciones que aseguren la evolución permanente de la organización para que ésta no solamente pueda adaptarse a los cambios del entorno sino también crecer y desarrollarse. Por otra parte, mejora la productividad racionalizando el empleo de los recursos humanos.

  13. Variabilidade genética de populações naturais de caroá por meio de marcadores RAPD Genetic variability estimated among caroá populations through RAPD markers

    OpenAIRE

    Daniela Garcia Silveira; Edson Perito Amorim; Onildo Nunes de Jesus; Fernanda Vidigal Duarte Souza; Kátia Nogueira Pestana; Vânia Jesus dos Santos; José Raniere Ferreira de Santana

    2009-01-01

    O objetivo deste trabalho foi quantificar a variabilidade genética entre e dentro de populações de caroá (Neoglaziovia variegata), por meio de marcadores "random amplified polymorphic DNA" (RAPD). Foram analisados 180 genótipos de caroá, provenientes dos municípios de Guanambi, Juazeiro e Valente, no Estado da Bahia. Foi observado elevado polimorfismo entre as populações de caroá. As dissimilaridades genéticas entre os genótipos variaram de 0,08 a 0,95, com média de 0,44.Avariância molecular ...

  14. Análise da ductilidade do concreto confinado de pilares de seção quadrada reforçados por encamisamento através sa absorção energética

    OpenAIRE

    Allende, K.; Souza, Vicente; Darwish, Fathi

    2008-01-01

    Neste estudo foram analisados os comportamentos dúcteis de pilares de seção quadrada pré-carregados, sob compressão excêntrica acidental, reforçados por encamisamento. A ductilidade do concreto confinado do núcleo encamisado foi avaliada em função da absorção energética deste sob o estado de compressão triaxial atuante devido ao cintamento conferido pelos estribos do reforço executado. Os resultados obtidos para a energia total absorvida pelo concreto confinado foram comparados à absorção ene...

  15. Mortalidad intrahospitalaria por accidente cerebrovascular

    Directory of Open Access Journals (Sweden)

    Federico Rodríguez Lucci

    2013-08-01

    Full Text Available La mortalidad global por accidente cerebrovascular (ACV ha disminuido en las últimas tres décadas, probablemente debido a un mejor control de los factores de riesgo vascular. La mortalidad hospitalaria por ACV ha sido tradicionalmente estimada entre 6 y 14% en la mayoría de las series comunicadas. Sin embargo, los datos de ensayos clínicos recientes sugieren que esta cifra sería sustancialmente menor. Se revisaron datos de pacientes internados con diagnóstico de ACV del Banco de Datos de Stroke de FLENI y los registros institucionales de mortalidad entre los años 2000 y 2010. Los subtipos de ACV isquémicos se clasificaron según criterios TOAST y los ACV hemorrágicos en hematomas intrapanquimatosos, hemorragias subaracnoideas aneurismáticas, malformaciones arteriovenosas y otros hematomas intraparenquimatosos. Se analizaron 1514 pacientes, 1079 (71% con ACV isquémico (grandes vasos 39%, cardioembólicos 27%, lacunares 9%, etiología indeterminada 14%, otras etiologías 11% y 435 (29% con ACV hemorrágico (intraparenquimatosos 27%, hemorragia subaracnoidea 30%, malformaciones arteriovenosas 25% y otros hematomas espontáneos 18%. Se registraron 38 muertes intrahospitalarias (17 ACV isquémicos y 21 ACV hemorrágicos, representando una mortalidad global del 2.5% (1.7% en ACV isquémicos y 4.8% en ACV hemorrágicos. No se registraron muertes asociadas al uso de fibrinolíticos endovenosos. La mortalidad intrahospitalaria en pacientes con ACV isquémico y hemorrágico en nuestro centro fue baja. El manejo en un centro dedicado a las enfermedades neurológicas y el enfoque multidisciplinario por personal médico y no médico entrenado en el cuidado de la enfermedad cerebrovascular podrían explicar, al menos en parte, estos resultados.

  16. Estratégias de enfrentamento utilizadas por pacientes renais crônicos em tratamento hemodialítico

    Directory of Open Access Journals (Sweden)

    Richardson Augusto Rosendo da Silva

    2016-03-01

    Full Text Available Resumo Objetivo: Conhecer as estratégias de enfrentamento utilizadas por pacientes renais crônicos submetidos ao tratamento hemodialítico, frente às dificuldades inerentes à doença. Métodos: Estudo descritivo, qualitativo, realizado com 30 pessoas que viviam com condições renais crônicas, em uma unidade de hemodiálise no Nordeste do Brasil. Os dados foram coletados de janeiro a março de 2013 por meio de um instrumento de entrevista semiestruturada e analisados segundo a análise de conteúdo, modalidade temática. Utilizou-se como referencial a teoria do Enfrentamento ou coping. Resultados: As categorias que emergiram dos discursos dos entrevistados foram: apoio familiar; apego à religião/crença; negação e esquiva; e resiliência. Conclusão: A forma para manejar as dificuldades inerentes à doença revelou-se por estratégias de enfrentamento tanto baseadas na emoção, como no problema. Assim, foram desenvolvidos esforços para administrar ou alterar os problemas iniciais, bem como tentativas de substituir ou regular o impacto emocional da doença.

  17. O acesso a informacao sobre higiene bucal e as perdas dentarias por carie entre adultos

    Directory of Open Access Journals (Sweden)

    Desiree Sant'Ana Haikal

    2014-01-01

    Full Text Available Objetivou-se testar a associação entre perdas dentárias por cárie (PDC e variáveis relativas ao acesso a informações em saúde bucal. Foram analisados dados de 780 adultos (35-44 anos participantes de um estudo epidemiológico. A variável dependente foi o total de PDC e as independentes foram reunidas em blocos de variáveis: demográficas e socioeconômicas; utilização dos serviços odontológicos; acesso a informações em saúde bucal (informações sobre como evitar problemas bucais, sobre higiene bucal e sobre dieta e; comportamentais. Conduziu-se regressão linear múltipla hierarquizada. O número médio de PDC foi de 7,03 (EP= 0,31 e 83% dos adultos haviam perdido algum dente por cárie. As PDC foram maiores entre os mais velhos, os com menor escolaridade, as mulheres, os que raramente ou nunca receberam informações sobre higiene bucal, os que escovavam os dentes uma vez ou menos ao dia e entre os que não usavam fio dental. Adultos que raramente/nunca receberam informações dos serviços odontológicos sobre higiene bucal perderam 2,15 dentes a mais por cárie que aqueles que sempre/frequentemente receberam tais informações (p = 0,000. Assim, sugere-se que a garantia do acesso à informação deva ser incentivada a fim de contribuir com maior equidade em saúde bucal.

  18. Evolution of NADPH-cytochrome P450 oxidoreductases (POR) in Apiales - POR 1 is missing

    DEFF Research Database (Denmark)

    Andersen, Trine Bundgaard; Hansen, Niels Bjørn; Laursen, Tomas

    2016-01-01

    to a huge number of different cytochromes P450s (from 50 to several hundred within one plant). Within the eudicotyledons, PORs can be divided into two major clades, POR 1 and POR 2. Based on our own sequencing analysis and publicly available data, we have identified 45 PORs from the angiosperm order Apiales...

  19. Vacancy ordered γ-Fe{sub 2}O{sub 3} nanoparticles functionalized with nanohydroxyapatite: XRD, FTIR, TEM, XPS and Mössbauer studies

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Guivar, Juan A., E-mail: juan.ramos5@unmsm.edu.pe [Faculty of Physical Sciences, National University of San Marcos, P. O. Box 14- 0149, Lima 14 (Peru); Sanches, Edgar A., E-mail: sanches.ufam@gmail.com [Federal University of Amazonas, Department of Physics, Manaus/AM (Brazil); Bruns, Florian, E-mail: f.bruns@tu-braunschweig.de [Institut für Physik der Kondensierten Materie, Technische Universität Braunschweig, 38110 Braunschweig (Germany); Sadrollahi, Elaheh, E-mail: elahe.sadrollahi@gmail.com [Institut für Physik der Kondensierten Materie, Technische Universität Braunschweig, 38110 Braunschweig (Germany); Morales, M.A., E-mail: marco.moralestorres@gmail.com [Department of Theoretical and Experimental Physics, UFRN, Natal, RN 59078- 970 (Brazil); López, Elvis O., E-mail: lopmezel@gmail.com [Brazilian Center for Research in Physics (CBPF), Rio de Janeiro, RJ 22290-180 (Brazil); Litterst, F. Jochen, E-mail: litterst@cbpf.br [Institut für Physik der Kondensierten Materie, Technische Universität Braunschweig, 38110 Braunschweig (Germany); Brazilian Center for Research in Physics (CBPF), Rio de Janeiro, RJ 22290-180 (Brazil)

    2016-12-15

    Graphical abstract: Possible bonding configuration in the γ-Fe{sub 2}O{sub 3} nanoparticles functionalized with nanoHAp. - Highlights: • Coprecipitation in alkaline medium for the synthesis of vacancy ordered γ-Fe{sub 2}O{sub 3}@HAp nanocomposite. • Samples were characterized by XRD, FTIR, XPS, TEM, VSM and Mössbauer spectroscopy. • The functionalization is explained with the binding of two oxygens of chemisorbed H{sub 2}O molecules at the common interface of HAp/C{sub 6}H{sub 8}O{sub 7}/γ-Fe{sub 2}O{sub 3}. - Abstract: Vacancy ordered maghemite (γ-Fe{sub 2}O{sub 3}) nanoparticles functionalized with nanohydroxyapatite (HAp – Ca{sub 10}(PO{sub 4}) {sub 6}(OH){sub 2}) have been successfully synthesized using an inexpensive co-precipitation chemical route. Evidence for the presence of vacancy order in maghemite was shown by the superstructure lines observed in X-ray diffraction. The adsorption of carboxyl groups of citric acid (C{sub 6}H{sub 8}O{sub 7}) onto γ-Fe{sub 2}O{sub 3} nanoparticles was investigated by FTIR, XPS and Mössbauer spectroscopy. From XPS surface analysis, two binding energies related to oxygen were attributed to bindings between C{sub 6}H{sub 8}O{sub 7}/γ- Fe{sub 2}O{sub 3} and C{sub 6}H{sub 8}O{sub 7}/HAp from an interfacial reaction promoted by strongly adsorbed H{sub 2}O molecules at the surface of these nanomaterials. Le Bail refinement of the XRD patterns showed the formation of well-crystallized pure tetragonal maghemite before and after functionalization with nanoHAp. The temperature dependence of hyperfine parameters of pure and functionalized γ-Fe{sub 2}O{sub 3} nanoparticles was investigated via Mössbauer spectroscopy. TEM revealed the formation of quasi-spherical γ- Fe{sub 2}O{sub 3} nanoparticles with an average diameter of ca. 12 nm and 16 nm before and after functionalization with nanoHAp in agreement with Le Bail refinement. Magnetometry measurements showed a saturation magnetization of 12 emu/g and a blocking

  20. Synthesis, structural, X-ray photoelectron spectroscopy (XPS) studies and IR induced anisotropy of Tl{sub 4}HgI{sub 6} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Parasyuk, O.V. [Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, Voli Ave. 13, Lutsk, 43025 (Ukraine); Khyzhun, O.Y. [Frantsevych Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanivsky St., 03142, Kyiv (Ukraine); Piasecki, M. [Institute of Physics, J. Dlugosz University Częstochowa, Armii Krajowej 13/15, Częstochowa (Poland); Kityk, I.V., E-mail: iwank74@gmail.com [Electrical Engineering Department, Czestochowa University Technology, Armii Krajowej 17, PL-42-217, Czestochowa (Poland); Lakshminarayana, G. [Wireless and Photonic Networks Research Centre, Faculty of Engineering, Universiti Putra Malaysia, 43400, Serdang, Selangor (Malaysia); Luzhnyi, I. [Frantsevych Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanivsky St., 03142, Kyiv (Ukraine); Fochuk, P.M. [Yuriy Fed’kovych Chernivtsi National University, 2 Kotziubynskoho Str., 58012, Chernivtsi (Ukraine); Fedorchuk, A.O. [Department of Inorganic and Organic Chemistry, Lviv National University of Veterinary Medicine and Biotechnologies, Pekarska Street 50, 79010, Lviv (Ukraine); Levkovets, S.I.; Yurchenko, O.M.; Piskach, L.V. [Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, Voli Ave. 13, Lutsk, 43025 (Ukraine)

    2017-02-01

    In the present work, we report on the synthesis and structural properties including X-ray protoelectron spectroscopy (XPS) analysis of Tl{sub 4}HgI{sub 6} crystals that were grown by Bridgman-Stockbarger method up to 80 mm in length and 18 mm in diameter. The existence of the ternary compound Tl{sub 4}HgI{sub 6} that melts incongruently at 641 K was confirmed. Phase equilibria and structural properties for the TlI–HgI{sub 2} system were investigated by differential thermal analysis (DTA) and X-ray diffraction (XRD) methods. X-ray photoelectron spectra were measured for both pristine and Ar{sup +} ion-bombarded Tl{sub 4}HgI{sub 6} single crystal surfaces. The data reveal that the Tl{sub 4}HgI{sub 6} single crystal is sensitive with respect to Ar{sup +} ion-bombardment as 3.0 keV Ar{sup +} irradiation over 5 min at an ion current density 14 μA/cm{sup 2} induces changes to the elemental stoichiometry of the Tl{sub 4}HgI{sub 6} surface, leading to a decrease of the mercury content in the topmost surface layers. X-ray photoelectron spectroscopy (XPS) measurements indicate very low hygroscopic nature of the Tl{sub 4}HgI{sub 6} single crystal surface. The IR coherent bicolor laser treatment at wavelengths 10.6/5.3 μm has shown an occurrence of anisotropy at wavelengths 1540 nm of Er:glass laser. This may open the applications of Tl{sub 4}HgI{sub 6} as a material for IR laser triggering. - Highlights: • Phase diagram of the HgI{sub 2}–TlI system was built. • Tl{sub 4}HgI{sub 6} single crystals were grown by Bridgman Stockbarger method. • XRD, XPS analysis was done. • Ir induced anisotropy was established. • The compounds may be proposed as Ir laser operated polarizers.

  1. XPS and NRA investigations during the fabrication of gold nanostructured functionalized screen-printed sensors for the detection of metallic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Jasmin, Jean-Philippe [Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR 8587, CNRS-Université Evry Val d’Essonne-CEA, 1 rue du père Jarlan, 91025 Evry Cedex (France); Miserque, Frédéric [Den-Service de la Corrosion et du Comportement des Matériaux dans leur Environnement (SCCME), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Dumas, Eddy [Institut Lavoisier de Versailles, UMR 8180, CNRS-Université de Versailles Saint-Quentin-en-Yvelines, 78035 Versailles (France); Vickridge, Ian; Ganem, Jean-Jacques [INSP, UMR 7588, CNRS- Université Pierre et Marie Curie, 4 place Jussieu, boîte courrier 840 75252 Paris, Cedex 05 (France); Cannizzo, Caroline, E-mail: caroline.cannizzo@univ-evry.fr [Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR 8587, CNRS-Université Evry Val d’Essonne-CEA, 1 rue du père Jarlan, 91025 Evry Cedex (France); Chaussé, Annie [Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR 8587, CNRS-Université Evry Val d’Essonne-CEA, 1 rue du père Jarlan, 91025 Evry Cedex (France)

    2017-03-01

    Highlights: • Functionalized nanostructured SPEs were made by multi-step diazonium salt chemistry. • Investigation of SPEs surface by XPS and NRA shows monolayer coverage by aminobenzyl groups. • Complete conversion of aminobenzyl groups into diazonium functions was also evidenced. • Covalent grafting of AuNPs onto SPEs lead to an unusual modification of Au-4f core level spectrum. • Ligand and lead signals showed the interest of nanostructurated SPEs for trace metals detection. - Abstract: An all covalent nanostructured lead sensor was built by the successive grafting of gold nanoparticles and carboxylic ligands at the surface of self-adhesive carbon screen-printed electrodes (SPEs). Surface analysis techniques were used in each step in order to investigate the structuration of this sensor. The self-adhesive surfaces were made from the electrochemical grafting of p-phenylenediamine at the surface of the SPEs via diazonium salts chemistry. The quantity of grafted aniline functions, estimated by Nuclear Reaction Analysis (NRA) performed with p-phenylenediamine labelled with {sup 15}N isotope, is in agreement with an almost complete coverage of the electrode surface. The subsequent diazotization of the aniline functions at the surface of the SPEs was performed; X-ray Photoelectron Spectroscopy (XPS) allowed us to consider a quantitative conversion of the aniline functions into diazonium moieties. The spontaneous grafting of gold nanoparticles on the as-obtained reactive surfaces ensures the nanostructuration of the material, and XPS studies showed that the covalent bonding of the gold nanoparticles at the surface of the SPEs induces a change both in the Au-4f (gold nanoparticles) and Cl-2p (carbon ink) core level signals. These unusual observations are explained by an interaction between the carbon ink constituting the substrate and the gold nanoparticles. Heavy and toxic metals are considered of major environmental concern because of their non

  2. XPS, TOF-SIMS, NEXAFS, and SPR Characterization of Nitrilotriacetic Acid-Terminated Self-Assembled Monloyers for Controllable Immobiliztion of Proteins

    International Nuclear Information System (INIS)

    Cheng, F.; Gamble, L.; Castner, D.

    2008-01-01

    For immobilization of proteins onto surfaces in a specific and controlled manner, it is important to start with a well-defined surface that contains specific binding sites surrounded by a nonfouling background. For immobilizing histidine-tagged (his-tagged) proteins, surfaces containing nitrilotriacetic acid (NTA) headgroups and oligo(ethylene glycol) (OEG) moieties are a widely used model system. The surface composition, structure, and reactivity of mixed NTA/OEG self-assembled monolayers (SAMs) on Au substrates were characterized in detail using X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and surface plasmon resonance (SPR) biosensoring. XPS results for sequential adsorption of NTA thiols followed by OEG thiols showed that OEG molecules were incorporated into an incompletely formed NTA monolayer until a complete mixed SAM was formed. The surface concentration of NTA headgroups was estimated to be 0.9-1.3 molecule/nm2 in the mixed NTA/OEG monolayers, compared to 1.9 molecule/nm2 in pure NTA monolayers. Angle-dependent XPS indicated NTA headgroups were slightly reoriented toward an upright position after OEG incorporation, and polarization-dependent NEXAFS results indicated increased ordering of the alkane chains of the molecules. Nitrogen-containing and OEG-related secondary ion fragments from the TOF-SIMS experiments confirmed the presence of NTA headgroups and OEG moieties in the monolayers. A multivariate peak intensity ratio was developed for estimating the relative NTA concentration in the outermost (10 Angstroms ) of the monolayers. SPR measurements of a his-tagged, humanized anti-lysozyme variable fragment (HuLys Fv) immobilized onto Ni(II)-treated mixed NTA/OEG and pure NTA monolayers demonstrated the reversible, site-specific immobilization of his-tagged HuLys Fv (108-205 ng/cm2) with dissociation rates (koff) between 1.0 x 10-4 and 2

  3. Miotoxicidade por organofosforados Organophosphate myotoxicity

    Directory of Open Access Journals (Sweden)

    Maria J. Cavaliere

    1996-06-01

    Full Text Available Os organofosforados são um grupo de compostos químicos amplamente utilizados em agropecuária como inseticidas, ocasionando intoxicações acidentais em animais e humanos, e mesmo sendo utilizados em tentativas de suicídio. A toxicidade desses produtos decorre sobretudo de insuficiência cárdio-respiratória por compromentimento do sistema nervoso autônomo. Sabe-se que alguns destes compostos induzem em animais de experimentação e em humanos, uma miopatia caracterizada por degeneração de células musculares, comprometendo sobretudo a musculatura respiratória. Baseado no fato de que este comprometimento contribui para a piora da função respiratória, propõe-se um protocolo de avaliação rotineira de miotoxicidade por compostos organofosforados, através de uma bateria mínima e suficiente de colorações e reações histoquímicas para quantificação da necrose muscular. Utilizaram-se como modelo experimental, grupos de ratos albinos (Wistar intoxicados com o organofosforado paraoxon, com e sem antídotos (atropina ou pralidoxima. Verificou-se nos grupos tratados com paraoxon e paraoxon mais atropina, necrose de fibras musculares no diafragma, que atingia em determinadas áreas até 15% das fibras. No grupo tratado com paraoxon mais pralidoxima, a necrose foi mínima, evidenciando o papel mioprotetor deste último antídoto.Organophosphates comprise a group of chemical compounds extensively used in farming as insecticides, which cause accidental poisoning in animals and men and are also used in suicide attempts. The toxicity of these compounds is due especially to the cardiac and respiratory impairment in consequence of autonomic nervous system disorders. However, it is known that some of these products induce a myopathy in experimental animals and humans. This myopathy is characterized by muscle cell degeneration, involving above all the respiratory muscles. Based on the fact that this involvement certainly enhances the

  4. ESTUDIO DE MEZCLA DE NANOPARTÍCULAS SULFURADAS Y OXIDADAS DE Mo Y DE Ni SOPORTADAS EN ALÚMINA, OBTENIDAS POR EL MÉTODO DE DESCOMPOSICIÓN TÉRMICA

    Directory of Open Access Journals (Sweden)

    Susana Martínez

    2011-01-01

    Full Text Available Se sintetizó una mezcla de nanopartículas sulfuradas y oxidadas de Mo y de Ni por el método de descomposición térmica, empleando un sistema de reflujo, dimetil disulfuro como agente sulfidizante, nonano como disolvente y una alúmina comercial que fungía como soporte. El sólido gris resultante se eliminó primero por decantación y luego por evaporación del líquido remanente bajo condiciones de vacío con el fin de evitar cambios, específicamente en las nanopartículas obtenidas. Una vez obtenidas las nanopartículas soportadas en alúmina se determinaron sus propiedades fisicoquímicas (morfología, estructura cristalina, estado de oxidación y composición elemental empleando las técnicas de HR-TEM, XPS e ICP. Los resultados de XPS y MET-HR muestran que el sólido esta conformado por nanopartículas de los metales seleccionados en sus formas oxidadas y sulfuradas tales como MoO3, MoS2, Ni2O3 y NiS, siendo la fase mayoritaria el MoO3. En los resultados no se evidenciaron fases mixtas o aleaciones de Mo y Ni.

  5. XPS Study of Chemical Changes on the La/Ce Treated Surface of A361 Aluminium Alloy Exposed to Air at Temperatures up to 500∘C

    Directory of Open Access Journals (Sweden)

    A. Pardo

    2009-01-01

    Full Text Available The chemical changes that take place on the rare earth treated surface of the A361 aluminium alloy exposed to air at temperatures between 100 and 500∘C have been examined using X-ray photoelectron spectroscopy (XPS. The most notable features discussed in this work are the disappearance of Mg and Si signals at the tested temperatures and disappearance of the Ce signal at temperatures of 400–500∘C. The biphasic microstructure of the A361 alloy, constituted by close to 12 wt% Si and the Al matrix, plays an important role in many of the results obtained. The notable growth of aluminium oxide across the conversion coating in the case of the Ce-treated surface is related to the structural transformation experienced by the cerium oxide coating at 400–500∘C.

  6. Influence of the lithium salt nature over the surface film formation on a graphite electrode in Li-ion batteries: An XPS study

    International Nuclear Information System (INIS)

    Leroy, S.; Martinez, H.; Dedryvere, R.; Lemordant, D.; Gonbeau, D.

    2007-01-01

    The formation of a passivation film (solid electrolyte interphase, SEI) at the surface of the negative electrode of full LiCoO 2 /graphite lithium-ion cells using different salts (LiBF 4 , LiPF 6 , LiTFSI, LiBETI) in carbonate solvents as electrolyte was investigated by X-ray photoelectron spectroscopy (XPS). The analyzes were carried out at different potential stages of the first cycle, showing the potential-dependent character of the surface film species formation and the specificity of each salt. At 3.8 V, for all salts, we have mainly identified carbonated species. Beyond this potential, the specific behavior of LiPF 6 was identified with a high LiF deposit, whereas for other salts, the formation process of the SEI appears controlled by the solvent decomposition of the electrolyte

  7. XPS and electrochemical evaluation of two-dimensional organic films obtained by chemical modification of self-assembled monolayers of (3-mercaptopropyl)trimethoxysilane on copper surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sinapi, Fabrice; Delhalle, Joseph; Mekhalif, Zineb

    2002-12-01

    In this study, a protective film consisting of an ultrathin two-dimensional polymer was prepared by hydrolysis of a (3-mercaptopropyl)trimethoxysilane (ethanol, 10{sup -3} M) self-assembled monolayer grafted onto copper and a subsequent modification with 3(heptofluoroisopropoxy)propyltrichlorosilane (toluene, 10{sup -3} M). Each stage of the preparation was characterized by X-ray photoelectron spectroscopy (XPS) while copper's corrosion-inhibitive properties were assessed by cyclic voltammetry measurements carried on in a 0.1 M NaOH medium. A remarkable enhancement of the copper's corrosion protection was obtained by the formation of lateral siloxane linkages between MPTS molecules absorbed followed by the grafting of the second molecular layer.

  8. Enhancing Electrochemical Water-Splitting Kinetics by Polarization-Driven Formation of Near-Surface Iron(0): An In Situ XPS Study on Perovskite-Type Electrodes**

    Science.gov (United States)

    Opitz, Alexander K; Nenning, Andreas; Rameshan, Christoph; Rameshan, Raffael; Blume, Raoul; Hävecker, Michael; Knop-Gericke, Axel; Rupprechter, Günther; Fleig, Jürgen; Klötzer, Bernhard

    2015-01-01

    In the search for optimized cathode materials for high-temperature electrolysis, mixed conducting oxides are highly promising candidates. This study deals with fundamentally novel insights into the relation between surface chemistry and electrocatalytic activity of lanthanum ferrite based electrolysis cathodes. For this means, near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) and impedance spectroscopy experiments were performed simultaneously on electrochemically polarized La0.6Sr0.4FeO3−δ (LSF) thin film electrodes. Under cathodic polarization the formation of Fe0 on the LSF surface could be observed, which was accompanied by a strong improvement of the electrochemical water splitting activity of the electrodes. This correlation suggests a fundamentally different water splitting mechanism in presence of the metallic iron species and may open novel paths in the search for electrodes with increased water splitting activity. PMID:25557533

  9. Loss of residual monomer from resilient lining materials processed by different methods = Perda de monômero residual de reembasadores resilientes processados por diferentes métodos

    Directory of Open Access Journals (Sweden)

    León, Blanca Liliana Torres

    2008-01-01

    Full Text Available Objetivo: Avaliar o monômero residual liberado de materiais resilientes para reembasamento polimerizados por diferentes métodos. Metodologia: Dois materiais foram testados: Ever-Soft polymerizado por banho quente de água ou por energia de microondas, e Light Liner polimerizado quimicamente e por luz visível (polimerização dual. O monômero residual liberado foi mensurado em 12 espécimes (40x10x0,3mm fabricados com cada material e método de polimerização. Os espécimes foram armazenados em água destilada por 168 horas a 37ºC, e analisados diariamente por espectrometria ultravioleta (Light Liner: 204nm, Ever-Soft: 206nm. Os dados foram analisados por ANOVA de fator único e teste de Bonferroni (a=0,05. O monômero residual liberado em relação ao tempo foi determinado por análise de regressão polinomial. Resultados: O monômero residual liberado em 168 horas do teste (µg/cm2 em espécimes polimerizados por banho de água quente (0,27±0,01µg/cm2 foi significativamente maior (P < 0,05 que em espécimes processados por energia de microondas (0,25±0,02µg/cm2. Ever-Soft mostrou uma redução na liberação de monomer residual com o tempo, tendendo a se estabilizar em 96 horas. Light Liner continuou a liberar monômero com o tempo. Conclusão: Ever-Soft pode ser polimerizado por energia de microondas. Os valores de monômero residual liberado foram baixos, e os níveis de monômero diminuíram com o tempo

  10. Aposentadoria por invalidez de trabalhadores da área da saúde de um hospital universitário Disability retirement of workers in the health field at a university hospital

    Directory of Open Access Journals (Sweden)

    Júlia Trevisan Martins

    2017-01-01

    Full Text Available Objetivo: Identificar as causas da aposentadoria por invalidez de trabalhadores da área da saúde de um hospital universitário. Método: Estudo seccional retrospectivo, realizado em 2014, por meio da análise dos registros dos prontuários de saúde dos trabalhadores da área da saúde do hospital universitário de uma universidade pública paranaense que se aposentaram por invalidez, no período de 2000 a 2013. Os dados foram analisados por meio de estatística descritiva e inferencial, considerando o nível de significância de 5% (p<0,05. Resultados: Foram concedidas 40 aposentadorias por invalidez. As principais causas da aposentadoria por invalidez foram os transtornos mentais e comportamentais (45,0%, seguidos pelas doenças osteomusculares (25,0%, as doenças do aparelho circulatório (7,5% e as neoplasias (7,5%. Não ouve associação significativa entre as variáveis estudadas. Conclusão: Os grupos de doenças que levaram a aposentadoria por invalidez são as mais comuns entre a população brasileira e passíveis de prevenção.

  11. Proton transfer and hydrogen bonding in the organic solid state: a combined XRD/XPS/ssNMR study of 17 organic acid-base complexes.

    Science.gov (United States)

    Stevens, Joanna S; Byard, Stephen J; Seaton, Colin C; Sadiq, Ghazala; Davey, Roger J; Schroeder, Sven L M

    2014-01-21

    The properties of nitrogen centres acting either as hydrogen-bond or Brønsted acceptors in solid molecular acid-base complexes have been probed by N 1s X-ray photoelectron spectroscopy (XPS) as well as (15)N solid-state nuclear magnetic resonance (ssNMR) spectroscopy and are interpreted with reference to local crystallographic structure information provided by X-ray diffraction (XRD). We have previously shown that the strong chemical shift of the N 1s binding energy associated with the protonation of nitrogen centres unequivocally distinguishes protonated (salt) from hydrogen-bonded (co-crystal) nitrogen species. This result is further supported by significant ssNMR shifts to low frequency, which occur with proton transfer from the acid to the base component. Generally, only minor chemical shifts occur upon co-crystal formation, unless a strong hydrogen bond is formed. CASTEP density functional theory (DFT) calculations of (15)N ssNMR isotropic chemical shifts correlate well with the experimental data, confirming that computational predictions of H-bond strengths and associated ssNMR chemical shifts allow the identification of salt and co-crystal structures (NMR crystallography). The excellent agreement between the conclusions drawn by XPS and the combined CASTEP/ssNMR investigations opens up a reliable avenue for local structure characterization in molecular systems even in the absence of crystal structure information, for example for non-crystalline or amorphous matter. The range of 17 different systems investigated in this study demonstrates the generic nature of this approach, which will be applicable to many other molecular materials in organic, physical, and materials chemistry.

  12. Corrosion inhibition performance of 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole for carbon steel in HCl solution: Gravimetric, electrochemical and XPS studies

    Energy Technology Data Exchange (ETDEWEB)

    Bouanis, M.; Tourabi, M.; Nyassi, A. [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Zarrouk, A. [LCAE-URAC 18, Faculty of Science, First Mohammed University, PO Box 717, M-60 000 Oujda (Morocco); Jama, C. [UMET-ISP, CNRS UMR 8207, ENSCL, Université Lille Nord de France, CS 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F., E-mail: fbentiss@gmail.com [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); UMET-ISP, CNRS UMR 8207, ENSCL, Université Lille Nord de France, CS 90108, F-59652 Villeneuve d' Ascq Cedex (France)

    2016-12-15

    Highlights: • 2,5-Bis(4-dimethylaminophenyl)-1,3,4-oxadiazole is good corrosion inhibitor for carbon steel in 1 M HCl. • XPS analysis has provided the composition of adsorbed protective layer on the steel surface. • The adsorption of the investigated 1,3,4-oxadiazole is mainly due to chemisorption. - Abstract: Corrosion inhibition of carbon steel in normal hydrochloric acid solution at 30 °C by 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole (DAPO) has been studied by weight loss measurements and electrochemical techniques (polarization and AC impedance). The experimental results showed that DAPO acted as an efficient inhibitor against the carbon steel corrosion in 1 M HCl, and its inhibition efficiency increased with the inhibitor concentration reaching a value up to 93% at 1 mM. Polarization studies showed that the DAPO was a mixed-type inhibitor. The adsorption of this 1,3,4-oxadiazole derivative on the carbon steel surface in 1 M HCl solution followed the Langmuir adsorption isotherm and the corresponding value of the standard Gibbs free energy of adsorption (ΔG°{sub ads}) is associated to a chemisorption mechanism. Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS) analyses were carried out to characterize the chemical composition of the inhibitive film formed on the steel surface. The surfaces studies showed that the inhibitive layer is composed of an iron oxide/hydroxide mixture where DAPO molecules are incorporated. The cytotoxicity of DAPO was also determined using cell culture system.

  13. XPS and NRA investigations during the fabrication of gold nanostructured functionalized screen-printed sensors for the detection of metallic pollutants

    Science.gov (United States)

    Jasmin, Jean-Philippe; Miserque, Frédéric; Dumas, Eddy; Vickridge, Ian; Ganem, Jean-Jacques; Cannizzo, Caroline; Chaussé, Annie

    2017-03-01

    An all covalent nanostructured lead sensor was built by the successive grafting of gold nanoparticles and carboxylic ligands at the surface of self-adhesive carbon screen-printed electrodes (SPEs). Surface analysis techniques were used in each step in order to investigate the structuration of this sensor. The self-adhesive surfaces were made from the electrochemical grafting of p-phenylenediamine at the surface of the SPEs via diazonium salts chemistry. The quantity of grafted aniline functions, estimated by Nuclear Reaction Analysis (NRA) performed with p-phenylenediamine labelled with 15N isotope, is in agreement with an almost complete coverage of the electrode surface. The subsequent diazotization of the aniline functions at the surface of the SPEs was performed; X-ray Photoelectron Spectroscopy (XPS) allowed us to consider a quantitative conversion of the aniline functions into diazonium moieties. The spontaneous grafting of gold nanoparticles on the as-obtained reactive surfaces ensures the nanostructuration of the material, and XPS studies showed that the covalent bonding of the gold nanoparticles at the surface of the SPEs induces a change both in the Au-4f (gold nanoparticles) and Cl-2p (carbon ink) core level signals. These unusual observations are explained by an interaction between the carbon ink constituting the substrate and the gold nanoparticles. Heavy and toxic metals are considered of major environmental concern because of their non-biodegradability. In a final step, the grafting of the carboxylic ligands at the surface of the SPEs and an accumulation step in the presence of lead(II) cations allowed us to evidence the interest of nanostructured materials as metallic pollutants sensors.

  14. Spray deposited Mg-doped SnO{sub 2} thin film LPG sensor: XPS and EDX analysis in relation to deposition temperature and doping

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Boben, E-mail: dr.boben1@gmail.com; Skariah, Benoy

    2015-03-15

    Highlights: • Mg doped SnO{sub 2} thin film significantly improves the LPG response to 93%. • Mg doping concentration up to 0.9 wt% is helpful in decreasing the grain size. • The O/Sn ratio supports excess oxygen in films whereas XPS suggests dissimilar chemical states. • Doping leads to an enhanced oxygen adsorption by a favourable crystallite orientation. • Adsorbed oxygen ions responsible for enhanced response can be perceived at the grain boundaries or at the surface, on account of the absence in the crystalline matrix. - Abstract: Magnesium doped SnO{sub 2} polycrystalline thin films are deposited by Spray pyrolysis by adding small amount of Mg between 0.3 and 1.2 wt%. Mg doping significantly modifies the gas sensing properties of tin oxide thin films by yielding (1 1 0) and (1 0 1) crystallite orientation to accommodate oxygen vacancies which lead to enhanced oxygen adsorption. A correlation is established between the crystallite orientation and the gas sensing magnitude by plotting the texture coefficient. The structure, surface chemical composition, and the optical and electrical properties are studied in relation to the gas sensing magnitude. It is shown that the magnesium doping in SnO{sub 2} maintains tetragonal rutile structure in stable cassiterite phase over low doping concentrations. The grain dimensions are influenced by both doping concentration and substrate temperature. Electronic surface states identified by the XPS are deconvoluted to establish the constituent oxygen states, while the EDX compositional analysis indicates added oxygen adsorption. As the temperature is raised for the response measurement, the adsorbed oxygen may transform to O{sup −} or O{sup 2−} which is supported by the increase of film resistance. It is shown that the sensor response to LPG is improved significantly (93%) by the addition of minor amounts of Mg to SnO{sub 2} thin film sensors.

  15. Osteomalacia inducida por tumor: hemangiopericitoma rinosinusal

    Directory of Open Access Journals (Sweden)

    Enriqueta M. Serafini

    2013-02-01

    Full Text Available La osteomalacia inducida por tumor es una rara enfermedad del metabolismo óseo caracterizada por el aumento en la excreción de fosfato a nivel renal seguido de hipofosfatemia. Es causada por agentes fosfatúricos producidos por determinados tumores. La resección total del tumor resulta en la completa reversión de las anormalidades bioquímicas, la desaparición de las manifestaciones clínicas y los hallazgos en los estudios por imágenes. Presentamos el caso de un varón de 61 años con cuadro clínico y laboratorio compatibles con osteomalacia oncogénica inducida por tumor mesenquimático de localización rinosinusal. En nuestro caso el diagnóstico histológico correspondió a una neoplasia de tipo vascular: hemangiopericitoma.

  16. Acidentes por animais peçonhentos e sistemas nacionais de informação Recording of venomous bites and stings by National Information Systems in Brazil

    Directory of Open Access Journals (Sweden)

    Rosany Bochner

    2002-06-01

    Full Text Available Neste trabalho foram analisados, sob a ótica da vigilância epidemiológica dos acidentes por animais peçonhentos, quatro sistemas nacionais de informação, o SINAN (Sistema de Informações de Agravos de Notificação, o SINITOX (Sistema Nacional de Informações Tóxico-Farmacológicas, o SIH-SUS (Sistema de Informações Hospitalares do Sistema Único de Saúde e o SIM (Sistema de Informações sobre Mortalidade. Concluiu-se que esses sistemas possuem características próprias, foram criados para atender demandas diferentes e apesar de produzirem um grande volume de dados, não conseguem, ainda que analisados em conjunto, dar conta da dimensão real desses acidentes.This paper highlights the epidemiological surveillance of venomous bites and stings according to four national information systems: SINAN (National Databank of Major Causes of Morbidity, SINITOX (National Information System on Poisoning, SIH-SUS (Hospital Information System of the Unified Health System, and SIM (Mortality Information System. The authors conclude that each information system has specific characteristics and addresses different demands. Although they contain large amounts of data, even if combined they fail to reflect the real magnitude of disorders caused by venomous bites and stings in the country.

  17. Encefalopatía por priones

    OpenAIRE

    Carlos Colegial; Federico Silva; Carlos Pérez; Myriam Saavedra; William Fernández; Rodrigo Pardo; Pablo Lorenzana; Ignacio Vergara

    1999-01-01

    Las encefalopatías espongiformes por priones son enfermedades neurodegenerativas que pueden ser esporádicas o transmisibles, ya sea por mecanismos infecciosos o hereditarios. Su investigación ha planteado enormes retos y en el recorrido histórico en busca de su causa dos médicos han recibido el premio Nobel de Medicina: Carleton Gajdusek, por sus trabajos en Nueva Guinea donde describió la transmisión infecciosa por ritos canibalísticos, que llevó a estudios de transmisión experimental en chi...

  18. Hematoquecia letal por angiostrongilosis abdominal

    Directory of Open Access Journals (Sweden)

    Gerzain Rodríguez

    2000-06-01

    Full Text Available Una niña indigena de 4 años de edad, procedente de Carurú, Vaupés, un municipio semiselvático de 2.000 habitantes, presentó hematoquecia repetida con sincope y muerte 4 días después, a pesar de recibir transfusiones sanguíneas. El estudio postmortem descubrió dos masas de 3-4 cm de diámetro en el ileon distal que, al microscopio, correspondieron a inflamación severa de toda la pared intestinal, rica en eosinofilos y en granulomas con células gigantes que circunscribian y fagocitaban huevos y larvas de Angiostrongylus costaricensis, helminto situado también dentro de las arterias de la submucosa, vasos que presentaban engrosamiento de la intima y focos con inflamación granulomatosa con eosinófilos. La niña no presentó leucocitosis ni eosinofilia. Este es el segundo caso de angiostrongilosis de esta región. El primero fue el de una mujer indigena de 34 años también con hematoquecia anemizante. La angiostrongilosis abdominal se diagnosticó por primera vez en Colombia en 1979, en un niño de 5 años, de Dagua, Valle. La niña aquí presentada es el sexto paciente con esta entidad en Colombia. La hematoquecia como manifestación predominante de la angiostrongilosis es extraordinaria para una enfermedad parasitaria; se ha registrado solamente en tres ocasiones anteriores. La abundancia de cristales de Charcot-Leyden, que se tiñen muy bien con la coloración de Ziehl-Neelsen o de Fite-Faraco, en los infiltrados de la pared intestinal. sugiere que su búsqueda en las heces puede ser una ayuda en el diagnóstico de casos sospechosos. pues, los huevos y las larvas no se eliminan en las heces y el diagnóstico definitivo de la angiostrongilosis es histopatológico. Revisamos las caracteristicas clinicas, parasitológicas e histopatológicas de esta parasitosis que será más prevalente en Colombia a medida que los médicos. especialmente los patólogos, la conozcan mejor.

  19. AVALIAÇÃO DA QUALIDADE MICROBIOLÓGICA DO QUEIJO MINAS FRESCAL PRODUZIDO POR LATICÍNIOS DO ESTADO DE MINAS GERAIS

    Directory of Open Access Journals (Sweden)

    Thaís Conceição Custódio Apolinário

    2015-01-01

    Full Text Available Este trabalho avaliou a presença de coliformes totais e termotolerantes, Salmonella spp., estafilococos coagulase positiva e Listeria monocytogenes em queijos Minas Frescal, produzidos por diferentes indústrias da região da Zona da Mata Mineira fiscalizadas por Serviços de Inspeção Federal, Estadual ou Municipal, num total de 31 amostras de queijos Minas Frescal. Foram encontradas 77,4% das amostras com contagens superiores ao preconizado pela legislação para coliformes totais, 54,8% para coliformes termotolerantes, 16,12% para estafilococos coagulase positiva e 9,6% para Listeria monocytogenes. Nenhuma das amostras apresentou contaminação por Salmonella spp. Diante disso, 80,6% das amostras analisadas encontravam-se imprópria para o consumo, por apresentar contagem de pelo menos um dos microrganismos analisados fora dos limites especificados pela legislação. Conclui-se que os queijos Minas Frescais não apresentam qualidade microbiológica satisfatória, o que compromete a segurança do alimento para o consumidor.

  20. Evolução das internações hospitalares por causas externas no sistema público de saúde - Brasil, 2002 a 2011

    Directory of Open Access Journals (Sweden)

    Márcio Dênis Medeiros Mascarenhas

    Full Text Available OBJETIVO: descrever a evolução das hospitalizações por causas externas no Brasil, no período de 2002 a 2011. MÉTODOS: estudo de séries temporais sobre internações por causas externas em hospitais públicos, utilizando dados do Sistema de Informações Hospitalares do Sistema Único de Saúde (SIH/SUS analisados segundo regressão linear simples. RESULTADOS: predominaram internações devidas às quedas (41% e aos acidentes de transporte terrestre (ATT (15%; observou-se aumento médio anual no coeficiente de internação hospitalar (∆CIH por causas externas da ordem de 13,1 internações para cada grupo de 100 mil habitantes (p<0,001; verificou-se aumento nas internações por quedas (∆CIH: 2,7/100 mil; p<0,001 e ATT (∆CIH: 2,2/100 mil; p=0,014, e redução nas internações por lesões autoprovocadas (∆CIH: -0,2/100 mil; p<0,001; internações por agressões permaneceram estáveis. CONCLUSÃO: o estudo confirma o aumento progressivo da demanda de internação hospitalar por causas externas, sobretudo causas acidentais, nos serviços públicos do Brasil, nos últimos anos.

  1. Antibiótico antifungico produzido por um estreptomiceto da região de Araraquara

    Directory of Open Access Journals (Sweden)

    K. Ujikawa

    2009-01-01

    Full Text Available

    Com o aumento significativo na incidência de infecções fúngicas invasivas durante a última década, principalmente em pacientes com câncer, AIDS, ou hospitalizados por período prolongado em unidades de terapia intensiva, há a necessidade da pesquisa de novos agentes antifúngicos com qualidade superior aos existentes. Esta pesquisa objetivou a procura de um microrganismo produtor de substâncias antibacterianas e antifúngicas. Microrganismos das amostras de solo da região de Araraquara, Brasil, foram coletados e analisados quanto ao seu potencial antimicrobiano contra microrganismos padrões (Staphylococcus aureus, Escherichia coli, Candida albicans, Aspergillus oryzae. Das 64 cepas isoladas, 34 apresentaram atividade antimicrobiana. A cepa Ar 4014 foi escolhida para dar continuidade ao trabalho por apresentar boa atividade antimicrobiana contra Candida albicans. Estudos fermentativos mostraram que os Meios 608-K e 602- B foram os melhores para produção e extração de substâncias antifúngicas de Ar 4014. Após cromatografia em coluna de sílica do extrato bruto, as frações ativas obtidas mostraram picos de absorção UV-VIS característicos de pentaenos normais. O antibiótico foi denominado provisoriamente Ara 4014-75. Palavras-chave: Antibiótico Ara 4014-75, Streptomyces, pentaenos, antifúngico, rastreamento.

  2. EXTRAÇÃO DE ISÓTOPOS ESTÁVEIS DE CO2 POR SUBLIMAÇÃO PARA DETERMINAÇÃO DO BALANÇO DE CARBONO DA BACIA AMAZÔNICA

    Directory of Open Access Journals (Sweden)

    Stephane Palma Crispim

    2017-05-01

    Full Text Available Apresentamos neste trabalho a implementação de um sistema de extração de isótopos estáveis de CO2 por sublimação, que esta sendo aplicado em amostras coletadas em dois diferentes pontos Rio Branco e Alta Floresta, localidades escolhidas através de estudos para a realização do balanço de carbono na Amazônia. As coletas são feitas por meio de aviões de pequeno porte, utilizando um sistema semiautomático desenvolvido pelo GMD/ESRL/NOAA que posteriormente é analisado no laboratório localizado no Instituto Nacional de Pesquisas Espaciais em São José dos Campos e encaminhado para a realização das extrações. As amostras contendo apenas CO2 puro, são seladas em chama e encaminhadas para a Holanda onde serão analisados δ¹³C e Δ17O.

  3. Verdad por definición

    Directory of Open Access Journals (Sweden)

    Garrido Garrido, Julián

    1997-07-01

    Full Text Available Not available.La verdad por definición es un tipo peculiar de verdad científica, distinguible de las verdades lógicas, matemáticas y empíricas. La definición, por su parte, designa diversos procedimientos de asignación de significado, cuyas diferencias exigen una adjetivación cuidadosa: definiciones ostensivas y operacionales, definiciones de diccionario y definiciones teóricas. Pero sólo las del último tipo son verdaderas por definición. En el presente artículo se precisa el concepto formal de definición teórica, se delimita la estructura de esos enunciados, se analiza la verdad por definición, y se comparan, por último, las definiciones teóricas con los otros tipos de definición.

  4. Encefalopatía por priones

    Directory of Open Access Journals (Sweden)

    Carlos Colegial

    1999-01-01

    Full Text Available Las encefalopatías espongiformes por priones son enfermedades neurodegenerativas que pueden ser esporádicas o transmisibles, ya sea por mecanismos infecciosos o hereditarios. Su investigación ha planteado enormes retos y en el recorrido histórico en busca de su causa dos médicos han recibido el premio Nobel de Medicina: Carleton Gajdusek, por sus trabajos en Nueva Guinea donde describió la transmisión infecciosa por ritos canibalísticos, que llevó a estudios de transmisión experimental en chimpancés y a su teoría de los "virus lentos" (por el largo período de incubación de la enfermedad.

  5. Portable exhauster POR-007/Skid E and POR-008/Skid F storage plan

    International Nuclear Information System (INIS)

    Nelson, O.D.

    1998-01-01

    This document provides storage requirements for 1,000 CFM portable exhausters POR-O07/Skid E and POR-008/Skid F. These requirements are presented in three parts: preparation for storage, storage maintenance and testing, and retrieval from storage. The exhauster component identification numbers listed in this document contain the prefix POR-007 or POR-008 depending on which exhauster is being used

  6. Surtos de intoxicação por salinomicina em chinchilas (Chinchilla lanigera

    Directory of Open Access Journals (Sweden)

    Ricardo B. Lucena

    2012-01-01

    Full Text Available Quatro surtos de intoxicação por salinomicina são descrito em chinchilas de três municípios do Estado do Rio Grande do Sul. Uma semana após a ingestão de ração contendo 37 ppm de salinomicina, aproximadamente duas mil chinchilas de quatro fazendas expostas diminuíram o consumo da ração. Quatrocentos e vinte sete chinchilas demonstraram apatia. Dessas, duzentos e setenta e sete desenvolveram decúbito esternal e lateral, dispneia e coma, seguidos de morte. As primeiras mortes ocorreram oito dias após a ingestão da ração. A evolução dos sinais clínicos até a morte ou eutanásia foi de 2-5 dias. Os exames bioquímicos do soro sanguíneo em quatro chinchilas revelaram níveis aumentados da alanina aminotransferase, aspartato transaminase, fosfatase alcalina, creatina cinase, glicose, triglicerídeos e colesterol total. Quarenta e cinco chinchilas foram submetidas à necropsia. Os achados macroscópicos consistiam de marcada lipidose hepática em todas as chinchilas necropsiadas; fetos em estado de decomposição em doze chinchilas que estavam prenhes. Microscopicamente, múltiplas fibras musculares esqueléticas estavam hipereosinofílicas, tumefeitas e com perda das estriações. Nas chinchilas que sobreviveram por mais dias era possível observar segmentos fragmentados de miofibras afetadas (necrose flocular e regeneração de miofibras. No fígado foi observada marcada degeneração gordurosa. Não foram observadas anormalidades microscópicas nos demais órgãos analisados. Análises à procura de aflatoxinas, resíduos de pesticidas e isolamento bacteriano foram negativos. A análise da ração por cromatografia líquida revelou 37ppm de salinomicina na ração. A ração suspeita foi administrada a 12 chinchilas, três das quais (25% morreram apresentando lesões semelhantes às observadas nas chinchilas com a doença natural. O diagnóstico de intoxicação por salinomicina foi baseado na epidemiologia, lesões histol

  7. Uso da proteção do complexo dentino-pulpar por discentes de odontologia

    Directory of Open Access Journals (Sweden)

    Daiane Casarin

    2016-10-01

    Full Text Available A proteção do complexo dentino pulpar depende de vários fatores, dentre eles, a idade do paciente, a condição pulpar prévia e a profundidade da lesão cariosa ou mesmo do preparo cavitário. Os materiais utilizados para a proteção, por sua vez, devem ser biocompatíveis, ter capacidade de induzir a formação de dentina reparadora dentre outros requisitos. O objetivo deste estudo foi conhecer o material de proteção do complexo dentino pulpar utilizado pelos discentes de odontologia tanto em nível de graduação, bem como em nível de pós-graduação. A metodologia utilizada foi quantitativa observacional do tipo descritiva e não probabilística, a qual envolveu 125 estudantes do último ano de graduação em odontologia e cirurgiões dentistas cursando pós-graduação em Dentística Restauradora em centros de estudos da cidade de Passo Fundo. A coleta de dados foi realizada por meio de um questionário adaptado de Takanashi (4 e os resultados foram analisados descritivamente no Excel, sendo que para cavidades rasas 88,8 % dos profissionais usam técnica adesiva convencional, cavidades médias 60,8% também opta por técnica adesiva convencional, para cavidades profundas 50,4% usa Hidróxido de Cálcio e nos casos de exposição pulpar 59,2% faz uso de pó de Hidróxido de Cálcio. Pode-se concluir que o hidróxido de cálcio foi o material de proteção pulpar mais usado tanto nas cavidades profundas, bem como, nas com exposição pulpar, já em cavidades médias e rasas a maioria optou por técnica adesiva convencional.

  8. A dor como quinto sinal vital: utilização da escala de avaliação por enfermeiros de um hospital geral

    OpenAIRE

    Bottega, Fernanda Hanke; Fontana, Rosane Teresinha

    2010-01-01

    Pesquisa descritiva, que objetivou descrever as impressões dos enfermeiros sobre o uso de uma escala visual analógica de avaliação da dor em adultos. Os dados foram coletados por meio de um questionário aplicado a 14 enfermeiros de um hospital e analisados mediante análise temática, resultando em seis categorias: a avaliação da dor e sua importância; a avaliação da dor oportunizando humanização do cuidado; a escala da dor medindo subjetividade; a avaliação da dor oportunizando humanização do ...

  9. Expressão da emoção por meio do desenho de uma criança hospitalizada

    Directory of Open Access Journals (Sweden)

    Souza Simone Vieira de

    2003-01-01

    Full Text Available O que desejamos com este trabalho é relatar a experiência de um estudo de caso de uma criança em idade pré-escolar hospitalizada. O foco do estudo é a expressão da emoção por meio de desenhos realizados pela criança em sessões de psicoterapia. Considera-se o desenho como uma atividade expressiva. Os desenhos acompanhados da fala são analisados à luz da teoria histórico-cultural. Os resultados evidenciaram ser o desenho um dos meios utilizados pela criança para expressar sua vivênciaemocional.

  10. Near-infrared light emission of Er{sup 3+}-doped zirconium oxide thin films: An optical, structural and XPS study

    Energy Technology Data Exchange (ETDEWEB)

    Clabel H, J.L., E-mail: jlch@df.ufscar.br [Departamento de Física, UFSCar, Caixa Postal 676, São Carlos 13565-905, SP (Brazil); Rivera, V.A.G.; Siu Li, M.; Nunes, L.A.O. [Instituto de Física de São Carlos, USP, Caixa Postal 369, São Carlos 13560-970, SP (Brazil); Leite, E.R. [Laboratório Interdisciplinar de Eletroquímica e Cerâmicas, UFSCar, Caixa Postal 676, São Carlos 13565-905, SP (Brazil); Schreiner, W.H. [Departamento de Física, UFPR, Caixa Postal 19044, Curitiba 81531-980, PR (Brazil); Marega, E. [Instituto de Física de São Carlos, USP, Caixa Postal 369, São Carlos 13560-970, SP (Brazil)

    2015-01-15

    Highlights: • Near-infrared emission properties of Er{sup 3+}-doped zirconium oxide thin films. • Modified with a fixed content of zinc oxide. • The improved luminescence is a function of the oxygen flux. • Bandwidth of 6.8–7.6 nm very useful for applications of erbium-doped solid lasers. - Abstract: This paper investigates the near-infrared emission and structural properties of Er{sup 3+}-doped zirconium oxide thin films modified with a fixed content of zinc oxide. The films were obtained by electron beam deposition on Si(1 0 0) substrates, followed by a thermal treatment with or without a controlled oxygen flow. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). Scanning electron microscopy (SEM) was used to evaluate the surface morphology, distributions and size of the grains in the films. The results confirmed significant changes in these films from thermal treatment with or without oxygen flow. Fourier transform infrared spectroscopy (FTIR) was used to analyze the absorption bands of the films. The photoluminescence (PL) measurement and {sup 4}I{sub 13/2} → {sup 4}I{sub 15/2} lifetime was measured under 980 nm near-infrared excitation. The effects of thermal treatment as well as the concentration of Er{sub 2}O{sub 3} on the PL emission intensity and lifetime in the near-infrared region (from the {sup 4}I{sub 13/2} → {sup 4}I{sub 15/2} radiative transition) were studied. Thermal treatment under a controlled atmosphere increased the PL emission intensity due to a diminution of the residual OH groups, as confirmed by the XPS and analysis and FTIR spectroscopy. The film modified with 3 mol% of Er{sub 2}O{sub 3} content annealed in oxygen flow shows an emission intensity of two orders of magnitude greater than the annealed film without oxygen flow at 1550 nm, nevertheless, the bandwidth was practically the same (7.6 nm) in both cases.

  11. XPS and STM study of the growth and structure of passive films in high temperature water on a nickel-base alloy

    Energy Technology Data Exchange (ETDEWEB)

    Machet, A.; Galtayries, A.; Zanna, S.; Klein, L.; Maurice, V.; Jolivet, P.; Foucault, M.; Combrade, P.; Scott, P.; Marcus, P

    2004-09-15

    The early stages of passivation in high temperature water of a nickel-chromium-iron alloy (Alloy 600) have been investigated by X-ray Photoelectron Spectroscopy (XPS) and Scanning Tunneling Microscopy (STM). The samples (polycrystal Ni-16Cr-9Fe (wt. %) and single crystal Ni-17Cr-7Fe (1 1 1)) have been exposed for short time periods (0.4-8.2 min) to high temperature (325 deg. C) and high pressure water, under controlled hydrogen pressure, in a microautoclave designed to transfer the samples from and to the XPS spectrometer without air exposure. In the early stages of oxidation of the alloy (0.4-4 min), an ultra-thin oxide layer (about 1 nm) is formed, which consists of chromium oxide (Cr{sub 2}O{sub 3}), according to the Cr 2p{sub 3/2} core level spectrum. An outer layer of Cr(OH){sub 3} with a very small amount of Ni(OH){sub 2} is also revealed by the Cr 2p{sub 3/2}, Ni 2p{sub 3/2}, and O 1s core level spectra. At this early stage, there is a temporary blocking of the growth of Cr{sub 2}O{sub 3}. For longer exposures (4-8 min), the Cr{sub 2}O{sub 3} inner layer becomes thicker, at the expense of the outer Cr(OH){sub 3} layer. This implies the transport of Cr and Ni through the oxide layer, and release of Ni{sup 2+} in the solution. The structure of the ultra-thin oxide film formed on a single crystal Ni-17Cr-7Fe(1 1 1) alloy was analysed by STM in the constant current mode; STM images reveal that, in the early stages of oxidation, the oxide is crystalline, and the observed structure is consistent with the hexagonal structure of the oxygen sub-lattice in the basal plane (0 0 0 1) of {alpha}-Cr{sub 2}O{sub 3}.

  12. Excreção de amônia por tambaqui (Colossoma macropomum) de acordo com variações na temperatura da água e massa do peixe

    OpenAIRE

    Ismiño-Orbe,Rosa Angélica; Araujo-Lima,Carlos Alberto Rego Monteiro; Gomes,Levy de Carvalho

    2003-01-01

    A amônia, produto de excreção dos peixes, é tóxica para organismos aquáticos. O objetivo deste trabalho foi quantificar taxas de excreção diária de amônia em tambaqui (Colossoma macropomum), principal espécie criada na Amazônia, que podem variar de acordo com a temperatura da água e a massa dos peixes. As taxas de excreção foram determinadas a cada 2 horas por um período de 24 horas e os resultados analisados por uma regressão linear múltipla. O tambaqui apresentou de dois a cinco picos de at...

  13. Mortalidade feminina por hipertensão: análise por causas múltiplas Mortality due to hypertension in women: a multiple cause analysis

    Directory of Open Access Journals (Sweden)

    Bruno Zoca de Oliveira

    2009-12-01

    Full Text Available INTRODUÇÃO: A prevalência da hipertensão arterial vem crescendo no país, constituindo-se em um problema de saúde pública por sua magnitude e dificuldades no controle. OBJETIVO: Avaliar a qualidade dos dados sobre hipertensão como causa de morte e verificar o ganho de informação na mortalidade por hipertensão arterial de mulheres de 10 a 49 anos, por meio da metodologia de análise por causas múltiplas de morte. MATERIAL E MÉTODOS: Foi constituída uma base de dados com 7.332 óbitos ocorridos no primeiro semestre de 2002 pertencentes ao "Estudo da Morbi-Mortalidade de Mulheres de 10 a 49 anos". A metodologia RAMOS (Reproductive Age Mortality Survey foi aplicada em todas as capitais de Estados brasileiros e Distrito Federal. Com as informações adicionais, foi preenchida uma nova declaração de óbito - DO-NOVA. Foram analisados dois conjuntos de dados (DO-ORIGINAL - antes da investigação - e DO-NOVA - após resgate das informações. Foram realizadas comparações segundo causas básicas e múltiplas por fontes dos dados (DO-O, DO-N. RESULTADOS E CONCLUSÃO: A DO-ORIGINAL apresentou algumas falhas quantitativas e qualitativas. Concluiu-se que a análise por causas múltiplas enriquece a informação, com base nas DO. São necessárias ações contínuas para um melhor preenchimento da DO, pelos médicos, e deve haver mais estudos que adotem a metodologia de causas múltiplas.INTRODUCTION: Hypertension is a public health problem due to its magnitude and difficulties in its control. OBJECTIVE: The objectives were to verify the quality of death certificates (DC and gain in information when the multiple cause of death methodology is performed, in DC of women from 10 to 49 years filled out with hypertension as an underlying or an associated cause of death. METHODS: The database consisted of 7,332 DC of the first semester of 2002 collected in the "Study of women in childbearing age, living in the capitals of all Brazilian States and

  14. Verdad por definición

    OpenAIRE

    Garrido Garrido, Julián

    1997-01-01

    Not available.La verdad por definición es un tipo peculiar de verdad científica, distinguible de las verdades lógicas, matemáticas y empíricas. La definición, por su parte, designa diversos procedimientos de asignación de significado, cuyas diferencias exigen una adjetivación cuidadosa: definiciones ostensivas y operacionales, definiciones de diccionario y definiciones teóricas. Pero sólo las del último tipo son verdaderas por definición. En el presente artículo se precisa el concepto formal ...

  15. Tatuaje por amalgama. Reporte de un caso

    OpenAIRE

    Luis Fang Mercado; Jacobo Ramos Manotas; Alejandra Herrera Herrera; Antonio Díaz Caballero

    2012-01-01

    El tatuaje por amalgama se origina por el depósito en el tejido conectivo subepitelial de fragmentos de amalgama resultado de procedimientos iatrogénicos por parte del operador. La profundidad a la que se encuentren albergados los residuos de este material influye en la presentación clínica de las lesiones. Radiográficamente se pueden identificar los fragmentos mientras tengan diámetros razonables; histológicamente se pueden observar las partículas de amalgama como gránulos oscuros, sólidos e...

  16. Clasificadores con pesos funcionales por puertas

    OpenAIRE

    Omari, Adil

    2015-01-01

    Los conjuntos de máquinas de aprendizaje representan una herramienta poderosa en muchas aplicaciones, porque ofrecen mejores soluciones que una única máquina, proporcionando, además, un diseño más sencillo y comprensible. Entre estos conjuntos cabe destacar, por la solidez de sus fundamentos y sus buenas prestaciones en problemas de regresión, las Mezclas de Expertos. Sin embargo, sus prestaciones para la la toma de decisiones están muy por debajo de las obtenidas por los mejores diseños. ...

  17. Caracterización de películas delgadas de nitruro de aluminio (AlN) fabricadas por la técnica de erosión iónica

    OpenAIRE

    GARCÍA MÉNDEZ, MANUEL; MORALES RODRÍGUEZ, SANTOS; DE LA CRUZ HERNÁNDEZ, WENCEL; RAMÍREZ VIDAURRI, LUCIANO ELIÉZER

    2008-01-01

    Se utilizó la técnica de erosión iónica reactiva para fabricar un conjunto de películas delgadas de nitruro de aluminio (AlN) a temperatura ambiente. Las muestras se analizaron por medio de difracción de rayos X y de espectroscopia de fotoemisión de electrones (XPS: X-ray photoemission spectroscopy) para analizar sus propiedades estructurales y electrónicas, respectivamente. Dependiendo de las condiciones experimentales de depósito, las películas presentan crecimien...

  18. Investigation of PVDF - TiO2 Nanoparticle Composite Thin Films by XPS, SEM and EDS for Use in the Capacitive Storage of Energy

    Science.gov (United States)

    Dillingham, T. Randy; Stufflebeam, Terry; Porter, Tim

    In this investigation, thin films of polyvinylidene fluoride (PVDF) containing nanoparticles of the ceramic titanium dioxide (TiO2) are synthesized using physical vapor deposition techniques. This combination of materials shows promise for possible use as the dielectric in capacitors, particularly regarding energy storage. This composite approach allows for the integration of complimentary features such as high dielectric permittivity from the integrated nanoparticles and high breakdown strength from the polymer matrix, resulting in a greatly enhanced energy density. Co-deposited films with a TiO2 content up to 8 percent have been synthesized and intermittent contact AFM and elemental mapping from EDS show that the dispersion of the nanoparticles in the material is homogeneous. Analysis from XPS indicates a defluorination of the films (C/F ratio greater than 1) from the deposition process, with the final film being a mixture of PVDF and polyvinyl fluoride (PVD). In addition, other parameters such as the dielectric constant and the breakdown voltage are given.

  19. Characterization of EUV irradiation effects on polystyrene derivatives studied by x-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS)

    Science.gov (United States)

    Yamamoto, Hiroki; Kozawa, Takahiro; Tagawa, Seiichi

    2011-04-01

    The trade-off among resolution, sensitivity, and line edge roughness (LER) is the most serious problem in actualization of extreme ultraviolet (EUV). As feature sizes are reduced, it becomes very strict to simultaneously meet these requirements. Also, reaction in resist materials induced by EUV photon is more complicate. In chemically amplified EUV resists, not acid generator but polymers mainly adsorbed EUV photons. The secondary electrons are generated from polymer upon exposure to ionizing radiation such as EUV radiation and electron beam. Therefore, the increase in secondary electrons generated by EUV photons adsorbed in resist film is very important factor in the resist design. Therefore, it is essential to know the ionization mechanisms of backbone polymers and understand the reaction mechanism in details in order to accomplish high sensitivity and ultra-fine pattern in EUV lithography. We investigated the photoelectron spectra of typical backbone polymers for chemically amplified EUV resists using ultraviolet photoelectron spectroscopy (UPS). Also, the structure degradations in polystyrene (PS) derivatives thin films induced by EUV radiation were analyzed by X-ray photoelectron spectroscopy (XPS) and UPS.

  20. Surface study of graphene ink for fine solid lines printed on BOPP Substrate in micro-flexographic printing using XPS analysis technique

    Science.gov (United States)

    Hassan, S.; Yusof, M. S.; Embong, Z.; Ding, S.; Maksud, M. I.

    2018-01-01

    Micro-flexographic printing is a combination of flexography and micro-contact printing technique. It is a new printing method for fine solid lines printing purpose. Graphene material has been used as depositing agent or printing ink in other printing technique like inkjet printing. This graphene ink is printed on biaxially oriented polypropylene (BOPP) by using Micro-flexographic printing technique. The choose of graphene as a printing ink is due to its wide application in producing electronic and micro-electronic devices such as Radio-frequency identification (RFID) and printed circuit board. The graphene printed on the surface of BOPP substrate was analyzed using X-Ray Photoelectron Spectroscopy (XPS). The positions for each synthetic component in the narrow scan are referred to the electron binding energy (eV). This research is focused on two narrow scan regions which are C 1s and O 1s. Further discussion of the narrow scan spectrum will be explained in detail. From the narrow scan analysis, it is proposed that from the surface adhesive properties of graphene, it is suitable as an alternative printing ink medium for Micro-flexographic printing technique in printing multiple fine solid lines at micro to nano scale feature.

  1. A near ambient pressure XPS study of subnanometer silver clusters on Al2O3 and TiO2 ultrathin film supports.

    Science.gov (United States)

    Mao, Bao-Hua; Chang, Rui; Shi, Lei; Zhuo, Qi-Qi; Rani, Sana; Liu, Xiao-Song; Tyo, Eric C; Vajda, Stefan; Wang, Sui-Dong; Liu, Zhi

    2014-12-28

    We have investigated model systems of silver clusters with different sizes (3 and 15 atoms) deposited on alumina and titania supports using ambient pressure X-ray photoelectron spectroscopy. The electronic structures of silver clusters and support materials are studied upon exposure to various atmospheres (ultrahigh vacuum, O2 and CO) at different temperatures. Compared to bulk silver, the binding energies of silver clusters are about 0.55 eV higher on TiO2 and 0.95 eV higher on Al2O3 due to the final state effect and the interaction with supports. No clear size effect of the silver XPS peak is observed on different silver clusters among these samples. Silver clusters on titania show better stability against sintering. Al 2p and Ti 2p core level peak positions of the alumina and titania support surfaces change upon exposure to oxygen while the Ag 3d core level position remains unchanged. We discuss the origin of these core level shifts and their implications for catalytic properties of Ag clusters.

  2. Adsorption of acetic acid on ice studied by ambient-pressure XPS and partial-electron-yield NEXAFS spectroscopy at 230-240 K.

    Science.gov (United States)

    Křepelová, Adéla; Bartels-Rausch, Thorsten; Brown, Matthew A; Bluhm, Hendrik; Ammann, Markus

    2013-01-17

    Ice plays a key role in the environment, and the ice-air interface influences heterogeneous chemical reactions between snowpack or cirrus clouds and the surrounding air. Soluble gases have been suspected to affect the topmost, disordered layer on ice (often referred to as a quasiliquid layer, QLL). Changes are especially expected in the hydrogen-bonding structure of water in the presence of solutes at the ice surface. Here, we used ambient-pressure X-ray photoelectron spectroscopy (XPS) to detect acetic acid at the ice surface at 230-240 K under atmospheric conditions for the first time. Electron-kinetic-energy-dependent C 1s spectra indicate that acetic acid remains confined to the topmost ice surface layers. Spectral analysis provides information about the protonation state of acetate at the ice surface. Surface-sensitive Auger-electron-yield C-edge near-edge X-ray absorption fine structure (NEXAFS) spectra were recorded to probe the molecular state of the adsorbed species. The O-edge NEXAFS spectra show only minor differences between clean ice and ice with adsorbed acetic acid and thus indicate that acetic acid does not lead to an extended disordered layer on the ice surface between 230 and 240 K.

  3. Physical aspects of relaxation and shake-up effects in XPS and core →2π* absorption spectra of CO chemisorbed on Ni (111)

    International Nuclear Information System (INIS)

    Gumhalter, B.

    1985-07-01

    The physical origin of the peculiar relaxation shifts and spectral shapes appearing in x-ray induced core-to-valence excitation and core level photoemission spectra of CO chemisorbed on Ni(111) are discussed and interpreted within a unique framework. Within the model presented the electronic transitions in core-to-valence excitation spectroscopy and XPS are shown to give rise to drastic electronic rearrangements within the adsorption system and to the charge shake-up in the CO 2π* derived resonance partly filled via the backdonation mechanism. Such singular relaxation processes, common to both spectroscopies, are closely related and can be treated on the same footing. This makes possible to establish unique relaxation shifts and spectral characteristics for two seemingly different experimental situations. The use of this formalism in analysing the experimental data enables one to estimate and distinguish between the extra-adsorbate (image or nonbonding) and intra-adsorbate (chemically induced) screening of the core holes created either by x-ray induced core-to-valence electronic transitions or core level photoionization in CO/Ni(111). (author)

  4. Elucidating the resistance to failure under tribological tests of various boron-based films by XPS and ToF-SIMS

    Science.gov (United States)

    Spadaro, F.; Rossi, A.; Lainé, E.; Woodward, P.; Spencer, N. D.

    2017-12-01

    Tribotests performed on boron-based thermal films have revealed higher mechanical durability and lower wear coefficients compared to results from tests performed on boron-free thermal films. In the current study, in order to follow and identify the tribochemical reactions taking place in the contact regions, post-characterization has been carried out on the steel ball and on the steel disc. The techniques adopted to achieve this goal were small-area X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary-ion mass spectroscopy (ToF-SIMS). The contact areas have been investigated before and after failure of the thermal films, revealing thermal-film removal inside the wear track on the disc and the presence of a transfer film in the contact area on the steel ball following tribotesting. Furthermore, borate contributions in the deeper layers within the tribo-stressed area on the disc were revealed at the end of the tribotest. These procedures shed light on the tribomechanical and tribochemical reactions taking place in the contact region, on the ability of boron species to sustain tribological stress and provide mechanical stability, and on the mechanical-mixing processes occurring within the sliding contacts. The mass spectra collected before tribotesting on all thermal films suggest the presence of phosphate- and borate-containing structures.

  5. The acid-base properties of the surface of native zinc oxide layers: An XPS study of adsorption of 1,2-diaminoethane

    Energy Technology Data Exchange (ETDEWEB)

    Ballerini, G. [Centre d' Etudes de Chimie Metallurgique, CNRS UPR 2801, 15 rue Georges Urbain, 94407 Vitry Cedex (France); Ogle, K. [Centre d' Etudes de Chimie Metallurgique, CNRS UPR 2801, 15 rue Georges Urbain, 94407 Vitry Cedex (France); Barthes-Labrousse, M.-G. [Centre d' Etudes de Chimie Metallurgique, CNRS UPR 2801, 15 rue Georges Urbain, 94407 Vitry Cedex (France)]. E-mail: Marie-Genevieve.Barthes@glvt-cnrs.fr

    2007-06-15

    The acid-base properties of native zinc oxide surfaces have been studied using X-ray photoelectron spectroscopy (XPS). The native layers of zinc oxide have been obtained by ageing mechanically polished pure zinc disks in a glass dryer for 1 month. Such a treatment lead to the formation of an unstable oxide layer and dehydroxylation has been observed during storage in vacuum. By following adsorption in ultrahigh vacuum of 1,2-diaminoethane (DAE) several types of active sites have been evidenced. Zinc cations react with the probe molecule following a Lewis acid/base interaction, while the hydroxyl and the carbonate-like species react following a Bronsted acid/base reaction. Although initial interaction via the Bronsted-like mechanisms is favoured, it has been shown that the resulting complexes are not stable. Under vacuum conditions, the adsorbed DAE molecules either partly desorb or modify their interaction mode with the surface to form additional Lewis-like bonded stable complexes. In addition, a cleaning effect of the molecule has been observed which lead to partial removal of the carbonate-like contamination.

  6. Surface characterization of insulin-coated Ti6Al4V medical implants conditioned in cell culture medium: An XPS study

    Energy Technology Data Exchange (ETDEWEB)

    Shchukarev, Andrey, E-mail: andrey.shchukarev@umu.se [Department of Chemistry, Umeå University, Umeå SE-90187 (Sweden); Malekzadeh, Behnosh Öhrnell [Department of Orthodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-40530 (Sweden); Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE-40530 (Sweden); Ransjö, Maria [Department of Orthodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-40530 (Sweden); Tengvall, Pentti [Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE-40530 (Sweden); Westerlund, Anna [Department of Orthodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-40530 (Sweden)

    2017-04-15

    Highlights: • In the absence of FBS, chemically immobilized insulin layer remains intact; • The immobilized insulin expose hydrophobic domains outward the implant; • In the presence of FBS, a partial replacement of insulin occurs; • The immobilized insulin stabilizes the secondary structure of adsorbed proteins. - Abstract: Surface characterization of insulin-coated Ti6Al4V medical implants, after incubation in α-minimum essential medium (α-MEM), was done by X-ray photoelectron spectroscopy (XPS), in order to analyze the insulin behavior at the implant – α-MEM interface. In the absence of serum proteins in cell culture medium, the coated insulin layer remained intact, but experienced a time-dependent structural transformation exposing hydrophobic parts of the protein toward the solution. The presence of fetal bovine serum (FBS) in the medium resulted in partial substitution of insulin by serum proteins. In spite of some insulin release, the remaining coated layer demonstrated a direct surface effect by stabilizing the structure of protein competitors, and by supporting the accumulation of calcium and phosphate ions at the interface. A structurally stable protein layer with incorporated calcium and phosphate ions at the implant–tissue interface could be an important prerequisite for enhanced bone formation.

  7. In Situ XPS Chemical Analysis of MnSiO3 Copper Diffusion Barrier Layer Formation and Simultaneous Fabrication of Metal Oxide Semiconductor Electrical Test MOS Structures.

    Science.gov (United States)

    Byrne, Conor; Brennan, Barry; McCoy, Anthony P; Bogan, Justin; Brady, Anita; Hughes, Greg

    2016-02-03

    Copper/SiO2/Si metal-oxide-semiconductor (MOS) devices both with and without a MnSiO3 barrier layer at the Cu/SiO2 interface have been fabricated in an ultrahigh vacuum X-ray photoelectron spectroscopy (XPS) system, which allows interface chemical characterization of the barrier formation process to be directly correlated with electrical testing of barrier layer effectiveness. Capacitance voltage (CV) analysis, before and after tube furnace anneals of the fabricated MOS structures showed that the presence of the MnSiO3 barrier layer significantly improved electric stability of the device structures. Evidence of improved adhesion of the deposited copper layer to the MnSiO3 surface compared to the clean SiO2 surface was apparent both from tape tests and while probing the samples during electrical testing. Secondary ion mass spectroscopy (SIMS) depth profiling measurements of the MOS test structures reveal distinct differences of copper diffusion into the SiO2 dielectric layers following the thermal anneal depending on the presence of the MnSiO3 barrier layer.

  8. XAFS and XPS studies on site occupation of Sm3+ ions in Sm doped M-type BaFe12O19

    International Nuclear Information System (INIS)

    Wang, Lixi; Zhang, Jing; Zhang, Qitu; Xu, Naicen; Song, Jie

    2015-01-01

    M-type barium hexaferrites doped with Sm 3+ , Ba 1−x Sm x Fe 12 O 19 (x=0.00, 0.05, 0.10, 0.15, 0.20, 0.30, 0.50) were prepared by conventional solid state reaction technique. Occupation of Sm 3+ ions in Ba 1−x Sm x Fe 12 O 19 was investigated by X-ray diffraction, X-ray absorption fine structure and X-ray photoelectron spectrum. The changes of crystal cell volume and valency of Sm, Ba and Fe ions indicated that Sm 3+ occupied Ba 2+ sites and Fe 3+ ions were partially reduced to Fe 2+ ions to keep the valence neutrality. - Highlights: • Sm 3+ doped BaFe 12 O 19 were synthesized by solid state reaction technique. • The occupation of Sm 3+ was investigated by XAFS, XPS and XRD. • Sm 3+ occupied Ba 2+ sites and Fe 3+ ions were partially reduced to Fe 2+ ions

  9. Corrosion inhibition performance of 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole for carbon steel in HCl solution: Gravimetric, electrochemical and XPS studies

    Science.gov (United States)

    Bouanis, M.; Tourabi, M.; Nyassi, A.; Zarrouk, A.; Jama, C.; Bentiss, F.

    2016-12-01

    Corrosion inhibition of carbon steel in normal hydrochloric acid solution at 30 °C by 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole (DAPO) has been studied by weight loss measurements and electrochemical techniques (polarization and AC impedance). The experimental results showed that DAPO acted as an efficient inhibitor against the carbon steel corrosion in 1 M HCl, and its inhibition efficiency increased with the inhibitor concentration reaching a value up to 93% at 1 mM. Polarization studies showed that the DAPO was a mixed-type inhibitor. The adsorption of this 1,3,4-oxadiazole derivative on the carbon steel surface in 1 M HCl solution followed the Langmuir adsorption isotherm and the corresponding value of the standard Gibbs free energy of adsorption (ΔG°ads) is associated to a chemisorption mechanism. Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS) analyses were carried out to characterize the chemical composition of the inhibitive film formed on the steel surface. The surfaces studies showed that the inhibitive layer is composed of an iron oxide/hydroxide mixture where DAPO molecules are incorporated. The cytotoxicity of DAPO was also determined using cell culture system.

  10. Surface characterization of insulin-coated Ti6Al4V medical implants conditioned in cell culture medium: An XPS study

    International Nuclear Information System (INIS)

    Shchukarev, Andrey; Malekzadeh, Behnosh Öhrnell; Ransjö, Maria; Tengvall, Pentti; Westerlund, Anna

    2017-01-01

    Highlights: • In the absence of FBS, chemically immobilized insulin layer remains intact; • The immobilized insulin expose hydrophobic domains outward the implant; • In the presence of FBS, a partial replacement of insulin occurs; • The immobilized insulin stabilizes the secondary structure of adsorbed proteins. - Abstract: Surface characterization of insulin-coated Ti6Al4V medical implants, after incubation in α-minimum essential medium (α-MEM), was done by X-ray photoelectron spectroscopy (XPS), in order to analyze the insulin behavior at the implant – α-MEM interface. In the absence of serum proteins in cell culture medium, the coated insulin layer remained intact, but experienced a time-dependent structural transformation exposing hydrophobic parts of the protein toward the solution. The presence of fetal bovine serum (FBS) in the medium resulted in partial substitution of insulin by serum proteins. In spite of some insulin release, the remaining coated layer demonstrated a direct surface effect by stabilizing the structure of protein competitors, and by supporting the accumulation of calcium and phosphate ions at the interface. A structurally stable protein layer with incorporated calcium and phosphate ions at the implant–tissue interface could be an important prerequisite for enhanced bone formation.

  11. XPS analysis and structural and morphological characterization of Cu{sub 2}ZnSnS{sub 4} thin films grown by sequential evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Gordillo, G. [Departamento de Física, Universidad Nacional de Colombia, Bogotá (Colombia); Calderón, C., E-mail: clcalderont@unal.edu.co [Departamento de Física, Universidad Nacional de Colombia, Bogotá (Colombia); Bartolo-Pérez, P. [Departamento de Física Aplicada, CINVESTAV-IPN, Mérida, Yuc. (Mexico)

    2014-06-01

    This work describes a procedure to grow single phase Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films with tetragonal-kesterite type structure, through sequential evaporation of the elemental metallic precursors under sulphur vapor supplied from an effusion cell. X-ray diffraction analysis (XRD) is mostly used for phase identification but cannot clearly distinguish the formation of secondary phases such as Cu{sub 2}SnS{sub 3} (CTS) because both compounds have the same diffraction pattern; therefore the use of a complementary technique is needed. Raman scattering analysis was used to distinguish these phases. The influence of the preparation conditions on the morphology and phases present in CZTS thin films were investigated through measurements of scanning electron microscopy (SEM) and XRD, respectively. From transmittance measurements, the energy band gap of the CZTS films was estimated to be around 1.45 eV. The limitation of XRD to identify some of the remaining phases after the growth process are investigated and the results of Raman analysis on the phases formed in samples grown by this method are presented. Further, the influence of the preparation conditions on the homogeneity of the chemical composition in the volume was studied by X-ray photoelectron spectroscopy (XPS) analysis.

  12. AFM, XPS and RBS studies of the growth process of CdS thin films on ITO/glass substrates deposited using an ammonia-free chemical process

    International Nuclear Information System (INIS)

    Mazon-Montijo, D.A.; Sotelo-Lerma, M.; Rodriguez-Fernandez, L.; Huerta, L.

    2010-01-01

    This paper deals with a detailed study of the growth stages of CdS thin films on ITO/glass substrates by chemical bath deposition (CBD). The chemical and morphological characterization was done through X-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectrometry (RBS), and atomic force microscopy (AFM) techniques. On the other hand, optical transmission and X-ray diffraction (XRD) measurements were performed in order to study the optical and structural properties of the films. The time, the chemistry, and morphology of the different stages that form the growth process by CBD were identified through these results. Furthermore, clear evidence was obtained of the formation of Cd(OH) 2 as the first chemical species adhered to the substrate surface which forms the first nucleation centers for a good CdS formation and growth. On the other hand, the ITO coating caused growth stages to occur earlier than in just glass substrates, with which we can obtain a determined thickness in a shorter deposition time. We were able to prove that CBD is a good technique for the manufacture of thin films of semiconductor materials, since the CdS film does not have any impurities. Completely formed films were transparent, uniform, with good adherence to the substrate, of a polycrystalline nature with a hexagonal structure. These results indicate that films obtained by CBD are good candidates to be applied in different optoelectronic devices.

  13. 14 Nobel, preocupados por el CERN

    CERN Multimedia

    Rivera, A

    2003-01-01

    "E l presidente del Consejo del CERN (Laboratorio Europeo de Fisica de Particulas, junto a Ginebra), Maurice Bourquin, ha recibido una carta firmada por un grupo de cientificos muy especiales: 14 premios Nobel de Fisica" (1 page).

  14. Micetoma por Nocardia brasiliensis: reporte de caso

    Directory of Open Access Journals (Sweden)

    Miriam Guevara R

    2003-07-01

    Full Text Available Se presenta el caso de un paciente peruano, agricultor, con una infección cutánea de origen traumático causada por Nocardia brasiliensis, que evolucionó hacia la amputación del miembro inferior afectado. El diagnóstico se realizó por examen directo y cultivo del espécimen.

  15. Tatuaje por amalgama. Reporte de un caso

    Directory of Open Access Journals (Sweden)

    Luis Fang Mercado

    2012-01-01

    Full Text Available El tatuaje por amalgama se origina por el depósito en el tejido conectivo subepitelial de fragmentos de amalgama resultado de procedimientos iatrogénicos por parte del operador. La profundidad a la que se encuentren albergados los residuos de este material influye en la presentación clínica de las lesiones. Radiográficamente se pueden identificar los fragmentos mientras tengan diámetros razonables; histológicamente se pueden observar las partículas de amalgama como gránulos oscuros, sólidos e irregulares dispuesto entre los haces de colágeno y vasos sanguíneos. Este artículo refiere el caso clínico de un paciente que presentó pigmentación por amalgama en mucosa vestibular, originada por una porción de amalgama usada como material obturador en una apicectomía del 11 realizada con anterioridad. Teniendo en cuenta las consideraciones clínicas y radiográficas se optó por realizar una segunda apicectomía con obturación retrógrada con MTA del 11. Durante el procedimiento quirúrgico se cureteó y adelgazó la cara interna del colgajo mucoperióstico para tratar de disminuir el grado de pigmentación.

  16. 4. El Morchid.xps

    African Journals Online (AJOL)

    21 juin 2017 ... marchés publics et aux débouchés extérieurs. Sur un autre registre, Easterly et Levine (1997) soulignent que le faible niveau de développement s'explique non seulement par des variables économiques classiques (faible taux de scolarisation, déficit public, distorsion des marchés de change, déficit ...

  17. O uso da gestão estratégica de custos por empresas do setor imobiliário

    Directory of Open Access Journals (Sweden)

    Rosenery Loureiro Lourenço

    2014-05-01

    Full Text Available O setor imobiliário é um importante integrante da economia nacional e, a exemplo dos demais setores, pode utilizar-se da gestão estratégica de custos como uma ferramenta diferencial para o gerenciamento dos negócios. O objetivo do presente estudo foi identificar de que forma empresas curitibanas utilizam-se da gestão estratégica de custos para a execução de suas atividades. De natureza quantitativa, este estudo descritivo utilizou a técnica de cluster para interpretar o comportamento de uma amostra não probabilística por adesão, coletada via survey e composta por 28 imobiliárias. Os dados foram analisados por meio de estatística descritiva e teste não paramétrico Mann-Whitney. Os resultados mostraram que as imobiliárias utilizam, de forma heterogênea, informações de custos e gestão estratégica para realizar suas atividades e que as empresas mais fortemente posicionadas em estratégias de diferenciação dão maior importância a questões capazes de gerar vantagem competitiva nesse mercado.

  18. Avaliação da versão brasileira da escala CRAFFT/CESARE para uso de drogas por adolescentes

    Directory of Open Access Journals (Sweden)

    Bruna Antunes de Aguiar Ximenes Pereira

    2016-01-01

    Full Text Available Resumo O artigo tem por objetivos apresentar a versão brasileira da escala CRAFFT de triagem de uso de drogas entre adolescentes e analisar sua compreensibilidade. Estudo descritivo e quantitativo, que avaliou versão brasileira da escala CRAFFT, e aferiu sua aplicabilidade em amostra por conveniência composta por escolares de 14 a 21 anos, regularmente matriculados em duas escolas técnicas. Foram analisados: a dificuldade de compreensão; a capacidade de avaliação através da comparação com o questionário do CEBRID aplicado em 28,8% dos estudantes; e o percentual de adolescentes considerados CRAFFT/CESARE positivos pelo ponto de corte. O coeficiente Kappa foi aplicado como medida de concordância entre os questionários e diferenças psicométricas com pontos de corte diversos foram avaliadas pela curva ROC. A escala CRAFFT/CESARE foi aplicada em 2005 alunos, sendo 1882 da faixa etária determinada. Apenas 2,2% dos adolescentes referiu dificuldade com o entendimento das questões. A especificidade da escala CRAFFT/CESARE foi de 73,3% e a sensibilidade 87,1%. O grau de concordância foi considerado bom (0,461. O CRAFFT/CESARE foi positivo em 36,2% dos adolescentes.

  19. Reaproveitamento do concentrado gerado por sistema de tratamento de água por osmose reversa em uma clínica de hemodiálise

    Directory of Open Access Journals (Sweden)

    Paulo Gil Siqueira de Faria

    Full Text Available RESUMO: O principal tratamento à doença renal crônica no Brasil, segundo o Censo Brasileiro de Nefrologia de 2013, é a hemodiálise, para a qual é necessária a utilização de água purificada em acordo com a Agência Nacional de Vigilância Sanitária (ANVISA e com os padrões internacionais do FDA, Food and Drugs Adminstration e da Association for Advancement of Medicine Instrumentation (AAMI. Para atender aos parâmetros estabelecidos, utiliza-se processo de purificação por osmose reversa (OR, onde ocorre a separação do afluente, através da membrana semipermeável, restando de um lado a água purificada e do outro lado o concentrado. O presente estudo visa abordar a viabilidade qualitativa e quantitativa do reaproveitamento deste concentrado, através de estudo de caso em unidade de OR instalada em uma clínica de hemodiálise na cidade de Curitiba. Foi realizada a avaliação experimental, através de análises físico-químicas e microbiológicas do concentrado, buscando atender as quatro classes de reuso sugeridas pela ABNT NBR 13969/97. Também foram analisados os parâmetros amônia, cloreto, cloro residual livre, dureza e ferro totais, fluoreto, nitratos, nitritos, sulfatos, sólidos totais dissolvidos e coliformes totais e comparados com o padrão de potabilidade. O volume de concentrado foi medido através do uso de hidrômetros em pontos estratégicos. Observou-se que a clínica reaproveita cerca de 23% do concentrado. Os resultados obtidos atendem às quatro classes de reuso, porém deve-se observar o parâmetro fluoreto cujo valor mostrou-se igual ao limite imposto pela norma de água potável.

  20. Mortalidade por armas de fogo no estado do Rio de Janeiro, Brasil: uma análise espacial

    Directory of Open Access Journals (Sweden)

    Szwarcwald Célia Landman

    1998-01-01

    Full Text Available O aumento da mortalidade por armas de fogo no estado do Rio de Janeiro, Brasil, tem tomado um aspecto alarmante. O objetivo deste estudo foi caracterizar a evolução temporal da mortalidade por armas de fogo neste estado, no período de 1979 a 1992, conforme sexo, idade e região de residência (capital, cinturão metropolitano e interior do estado e estudar a propagação da epidemia ao longo do tempo e do espaço, com a utilização de técnicas de análise estatística espacial. No período analisado, a mortalidade por armas de fogo teve o seu maior crescimento entre adolescentes de 15 a 19 anos, do sexo masculino; estas taxas variaram de 13 a 16% para este grupo, conforme a região de residência. Para o grupo das crianças de 10 a 14 anos, a mortalidade por armas de fogo teve um acréscimo de 10% ao ano. Foi nítida a interiorização da mortalidade por armas de fogo. No início da série, observou-se uma direção preferencial de disseminação, ao longo dos municípios situados na costa leste do estado, acompanhando o trajeto de uma rodovia federal. Entre 1990 e 1992, entretanto, a difusão ocorreu em praticamente todas as direções. A constatação empírica da expansão generalizada da mortalidade por armas de fogo nega as afirmações corriqueiras de concentração da violência nos bolsões de pobreza das metrópoles brasileiras. Os programas para prevenir e controlar a epidemia devem abordar o problema sob diferentes aspectos, enfocando questões tanto no plano coletivo (proliferação de armas entre a população vinculada ao contrabando internacional de armas, aumento da criminalidade, expansão do tráfico de drogas e exclusão de oportunidades sociais, assim como no plano individual (relações e interações dos jovens com seu ambiente, em nível da família, da escola e da sociedade.

  1. Avaliação dos selantes de fossas e fissuras aplicados por estudantes de Odontologia

    Directory of Open Access Journals (Sweden)

    Márcio Cristiano de Souza Rastelli

    Full Text Available INTRODUÇÃO: Selantes de fossas e fissuras são indicados para prevenir lesão de cárie em superfícies oclusais. OBJETIVO: O objetivo deste estudo foi avaliar os selantes de fossas e fissuras aplicados por estudantes do Curso de Graduação em Odontologia da Universidade Regional de Blumenau (FURB, Santa Catarina. MATERIAL E MÉTODO: O estudo descritivo retrospectivo desenvolveu-se em três etapas: na primeira, procedeu-se à análise dos prontuários do Setor de Triagem, tendo como critério de inclusão a existência de radiografias dos dentes selados. Na segunda etapa, analisaram-se as radiografias dos prontuários selecionados e a história clínica da criança. A terceira etapa foi realizada por meio de exames clínicos e radiográficos, pelos quais eram verificadas as condições dos selantes de fossas e fissuras. RESULTADO: Foram analisados 800 prontuários, sendo selecionados 131 (16,37% para a segunda etapa, quando se observou que 321 selantes de fossas e fissuras foram aplicados. Compareceram à consulta de controle 119 (90,84% crianças, ocasião em que se confirmou a aplicação de 160 (49,85% selantes resinosos, 126 (39,25% com cimento de ionômero de vidro e 35 (10,90% com resina flow. Foram observados 296 (92,21% selantes em dentes permanentes. Ao exame clínico, verificou-se que 114 (35,51% selantes haviam sido perdidos totalmente em diferentes períodos de tempo. Nenhuma lesão de cárie foi observada em 294 (91,59% dentes selados. CONCLUSÃO: Verificou-se que os selantes de fossas e fissuras, aplicados por estudantes do Curso de Odontologia da FURB, foram eficazes na manutenção da maioria das superfícies dentárias livres de lesão de cárie, mesmo quando foram perdidos parcial ou totalmente.

  2. The adsorption of NO on an oxygen pre-covered Pt(1 1 1) surface: in situ high-resolution XPS combined with molecular beam studies

    Science.gov (United States)

    Zhu, J. F.; Kinne, M.; Fuhrmann, T.; Tränkenschuh, B.; Denecke, R.; Steinrück, H.-P.

    2003-12-01

    Adsorption of NO on a Pt(1 1 1) surface pre-covered with a p(2 × 2) atomic oxygen layer has been studied in situ by high-resolution X-ray photoelectron spectroscopy and temperature-programmed XPS using third-generation synchrotron radiation at BESSY II, Berlin, combined with molecular beam techniques and ex situ by low energy electron diffraction and temperature-programmed desorption. O 1s XP spectra reveal that an ordered p(2 × 2)-O layer dramatically changes the adsorption behavior of NO as compared to the clean surface. The atomic oxygen occupies fcc hollow sites, and therefore blocks NO adsorption on these sites, which are energetically preferred on clean Pt(1 1 1). As a consequence, NO populates on-top sites at low coverage. At 110 K for higher coverages, NO can additionally adsorb on hcp hollow sites, thereby inducing a shift of the O 1s binding energy of atomic oxygen towards lower energies by about 0.25 eV. The bond strength of the hcp hollow NO species to the substrate is weakened by the presence of atomic oxygen. A sharp p(2 × 2) LEED pattern is observed for NO adsorption on the oxygen pre-covered surface, up to saturation coverage. The total saturation coverage of NO on Pt(1 1 1) pre-covered with varying amounts of oxygen (below 0.25 ML) decreases linearly with the coverage of oxygen. The initial sticking coefficient of NO is reduced from 0.96 on clean Pt(1 1 1) to 0.88 on a p(2 × 2) oxygen pre-covered surface.

  3. Assessment of the surface chemistry of carbon blacks by TGA-MS, XPS and inverse gas chromatography using statistical chemometric analysis

    International Nuclear Information System (INIS)

    Strzemiecka, Beata; Voelkel, Adam; Donate-Robles, Jessica; Martín-Martínez, José Miguel

    2014-01-01

    Highlights: • Carbon blacks with lower specific surface area had basic character (electron donor) due to C=O and C-O groups. • Carbon blacks with higher specific surface area had acidic character (acceptor electron) due to OH groups. • Total surface energy and its dispersive component of carbon blacks increased by increasing their specific surface area. (table) - Abstract: Four carbon blacks with different specific surface areas and surface chemistries (C32, C71, C159 and C178) were analyzed by transmission electron microscopy (TEM) and nitrogen adsorption isotherms at 77 K. Their surface chemistries were analyzed by X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis coupled with mass spectrometry (TGA-MS) and inverse gas chromatography (IGC). The carbon blacks contained 2.7–5.8 wt% volatiles corresponding to -OH, C-O, C=O and COO groups. The surface chemistry parameters obtained with the different experimental techniques were inter-related by using chemometric statistical analysis tools. The application of this methodology showed that the carbon blacks with lower specific surface area (C32 and C71) had basic character (electron donor) mainly due to C=O and C-O groups, whereas the carbon black with the highest specific surface area (C178) showed acidic character (acceptor electron) due to its high content of OH groups. Moreover, the total surface energy and the dispersive component of the surface energy of the carbon blacks increased with the increase of their specific surface area. In general the specific interactions of the carbon blacks also increased with the increase of their specific surface area although C71 is exceptional due to higher oxygen content corresponding to C-O groups

  4. Resistencia a la corrosión y desgaste de recubrinnientos deTiN obtenidos por PVD

    Directory of Open Access Journals (Sweden)

    Conde, A.

    2005-12-01

    Full Text Available Surface hardening techniques for metallic alloys are widely used to achieve layers of very high hardness and corrosion and wear resistance. In the present paper TiN coatings are obtained by PVD on a tool steel. The films are characterized by SEM, X-ray diffraction and XPS. Corrosion behaviour in NaCl solution showed the importance of the presence of defects on the PVD coating due to the different electrochemical behaviour of the steel base. Pin-on-disk measurements at approximately 40% RH against a corundum (Al2O3 ball showed a significant decrease in the wear rate compared with the results for the standard tool steel.

    Los tratamientos de endurecimiento superficial de aleaciones metálicas se utilizan para lograr capas de muy elevada dureza, resistencia a la corrosión y desgaste. En este trabajo, se estudia el comportamiento de recubrimientos de TiN obtenidos mediante PVD sobre aceros de herramientas. Las capas obtenidas se caracterizan mediante microscopía electrónica de barrido, difracción de rayos X y XPS. Se analiza el comportamiento frente a la corrosión de las capas protectoras, así como la influencia del substrato en su comportamiento en soluciones de NaCl. Finalmente, se realizan ensayos de desgaste por deslizamiento en seco mediante la técnica de pin-on-disk, comprobándose la mayor resistencia de estas capas.

  5. A Multi-technique Characterization of Adsorbed Protein Films: Orientation and Structure by ToF-SIMS, NEXAFS, SFG, and XPS

    Science.gov (United States)

    Baio, Joseph E.

    There are many techniques that allow surface scientists to study interfaces. However, few are routinely applied to probe biological surfaces. The work presented here demonstrates how detailed information about the conformation, orientation, chemical state, and molecular structure of biological molecules immobilized onto a surface can be assessed by electron spectroscopy, mass spectrometry, and nonlinear vibrational spectroscopy techniques. This investigation began with the development of simple model systems (small proteins, and peptides) and evolved into a study of more complex --- real world systems. Initially, two model systems based on the chemical and electrostatic immobilization of a small rigid protein (Protein G B1 domain, 6kDa) were built to develop the capabilities of time-of-flight secondary ion mass spectrometry (ToFSIMS), near edge X-ray absorption fine structure spectroscopy (NEXAFS) and sum frequency generation (SFG) spectroscopy as tools to probe the structure of surface immobilized proteins. X-ray photoelectron spectroscopy (XPS) was used to measure the amount of immobilized protein and ToF-SIMS sampled the amino acid composition of the exposed surface of the protein film. Within the ToF-SIMS spectra, an enrichment of secondary ions from amino acids located at opposite ends of the proteins were used to describe protein orientation. SFG spectral peaks characteristic of ordered alpha-helix and beta-sheet elements were observed for both systems and the phase of the peaks indicated a predominantly upright orientation for both the covalent and electrostatic configurations. Polarization dependence of the NEXAFS signal from the N 1s to pi* transition of the peptide bonds that make up the beta-sheets also indicated protein ordering at the surface. Building upon the Protein G B1 studies, the orientation and structure of a surface immobilized antibody (HuLys Fv: variant of humanized anti-lysozyme variable fragment, 26kDa) was characterized across two

  6. Assessment of the learning curves for photoselective vaporization of the prostate using GreenLight™ 180-Watt-XPS laser therapy: defining the intra-operative parameters within a prospective cohort.

    Science.gov (United States)

    Misraï, Vincent; Faron, Matthieu; Guillotreau, Julien; Bruguière, Eric; Bordier, Benoit; Shariat, Shahrokh F; Rouprêt, Morgan

    2014-04-01

    To assess the learning curves for the intra-operative parameters of the GreenLight™ 180-W XPS for photoselective vaporization of the prostate (PVP). A prospective study was conducted on 200 men who underwent PVP using the GreenLight™ 180-W XPS over 20 months. The population was divided into four consecutive equal groups. Evolution of lasing parameters was the main endpoint to reach an average energy of 5 kJ per prostate volume and to reach a lasing time/operative time (LT/OT) ratio of 66-80 %. Changes in the IPSS and prostate volume were also evaluated 12 weeks later. Total energy delivered (energy/ml of prostate) and the LT/OT ratio significantly increased over time (p learning curves within multiple intra-operative parameters. The PVP learning curves required at least 120 procedures until it met all intra-operative parameters of experts in this field.

  7. Thorium effect on the oxidation of uranium: Photoelectron spectroscopy (XPS/UPS) and cyclic voltammetry (CV) investigation on (U1 − xThx)O2 (x = 0 to 1) thin films

    NARCIS (Netherlands)

    Cakir, P.; Eloirdi, R; Huber, F.; Konings, R.J.M.; Gouder, T

    2017-01-01

    Thin films of U1− xThxO2 (x = 0 to 1) have been deposited via reactive DC sputter technique and characterized by X-ray/Ultra-violet Photoelectron Spectroscopy (XPS/UPS), X-ray Powder Diffractometer (XRD) and Cyclic Voltammetry (CV) in order to understand the

  8. A perspective on two chemometrics tools: PCA and MCR, and introduction of a new one: Pattern recognition entropy (PRE), as applied to XPS and ToF-SIMS depth profiles of organic and inorganic materials

    Science.gov (United States)

    Chatterjee, Shiladitya; Singh, Bhupinder; Diwan, Anubhav; Lee, Zheng Rong; Engelhard, Mark H.; Terry, Jeff; Tolley, H. Dennis; Gallagher, Neal B.; Linford, Matthew R.

    2018-03-01

    X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) are much used analytical techniques that provide information about the outermost atomic and molecular layers of materials. In this work, we discuss the application of multivariate spectral techniques, including principal component analysis (PCA) and multivariate curve resolution (MCR), to the analysis of XPS and ToF-SIMS depth profiles. Multivariate analyses often provide insight into data sets that is not easily obtained in a univariate fashion. Pattern recognition entropy (PRE), which has its roots in Shannon's information theory, is also introduced. This approach is not the same as the mutual information/entropy approaches sometimes used in data processing. A discussion of the theory of each technique is presented. PCA, MCR, and PRE are applied to four different data sets obtained from: a ToF-SIMS depth profile through ca. 100 nm of plasma polymerized C3F6 on Si, a ToF-SIMS depth profile through ca. 100 nm of plasma polymerized PNIPAM (poly (N-isopropylacrylamide)) on Si, an XPS depth profile through a film of SiO2 on Si, and an XPS depth profile through a film of Ta2O5 on Ta. PCA, MCR, and PRE reveal the presence of interfaces in the films, and often indicate that the first few scans in the depth profiles are different from those that follow. PRE and backward difference PRE provide this information in a straightforward fashion. Rises in the PRE signals at interfaces suggest greater complexity to the corresponding spectra. Results from PCA, especially for the higher principal components, were sometimes difficult to understand. MCR analyses were generally more interpretable.

  9. Fe0.88Cr0.12 and Fe0.85Cr0.15 alloys exposed to air at 870 K studied by TMS, CEMS and XPS

    Science.gov (United States)

    Idczak, R.; Idczak, K.; Konieczny, R.

    2018-01-01

    The room temperature 57Fe Mössbauer and XPS spectra were measured for polycrystalline Fe0.88Cr0.12 and Fe0.85Cr0.15 alloys which were exposed to air at 870 K. The spectra were collected using three techniques: the transmission Mössbauer spectroscopy (TMS), the conversion electron Mössbauer spectroscopy (CEMS) and the X-ray photoelectron spectroscopy (XPS). The combination of these experimental methods allows to determine changes in atomic composition in the bulk, in the subsurface layer and on the surface of the studied alloys. The results obtained by XPS confirm the strong chromium segregation process on the surface of Fe0.88Cr0.12 and Fe0.85Cr0.15 alloys. At the same time, the CEMS and TMS measurements reveal that in both samples, during the exposure to air at 870 K, iron oxides were formed. These findings lead to conclusion that the formation of a stable Cr oxide film on the surface of Fe0.88Cr0.12 and Fe0.85Cr0.15 alloys, does not prevent atmospheric corrosion at 870 K. Moreover, the observed by CEMS and TMS, oxidation process of iron atoms is slower for Fe0.88Cr0.12 than for Fe0.85Cr0.15. This fact is in agreement with XPS results which show that Cr surface segregation process is more effective in case of Fe0.88Cr0.12.

  10. AVALIAÇÃO DA ATIVIDADE ANTIOXIDANTE IN VITRO DOS CHÁS MATE E VERDE ANTES E APÓS A BIOTRANSFORMAÇÃO POR LIPASES

    Directory of Open Access Journals (Sweden)

    Camila Morais Gonçalves da SILVA

    2012-12-01

    Full Text Available Os chás mate e verde, comuns na dieta brasileira, foram avaliados primeiramente quanto a sua composição: os polifenóis totais e os flavonóides totais das matrizes alimentares in natura foram quantificados por espectrofotometria, enquanto o perfil de composição foi analisado por espectrometria de massas (ESI-MS. Posteriormente, a atividade antioxidante foi avaliada por ensaios in vitro, antes e após a biotransformação enzimática por lipase de pâncreas de porco e lipase de Aspergillus niger comerciais, nas condições de reação estabelecidas pelo fabricante. Amostras dessas matrizes foram avaliadas por diferentes métodos: FRAP, DPPH, co-oxidação β-caroteno/ ácido linoléico, ORAC e a peroxidação lipídica foi avaliada pelo índice de TBARS. Subsequentemente foi realizada uma comparação entre o potencial antioxidante dos chás in natura, sem biotransformação, com os chás liofilizados também não biotransformados, a fim de avaliar se o processo de liofilização poderia comprometer a capacidade antioxidante da amostra, já que este poderia ser utilizado como método de conservação das amostras para futuros testes. A biotransformação enzimática aumentou a atividade antioxidante de ambos os chás, enquanto o processo de liofilização não promoveu alterações no potencial antioxidante das matrizes estudadas, quando comparadas as amostras in natura.

  11. Gravidade das coinfecções virais em lactentes hospitalizados com infecção por vírus sincicial respiratório

    Directory of Open Access Journals (Sweden)

    Milena De Paulis

    2011-08-01

    Full Text Available OBJETIVO: Comparar a gravidade de infecções causadas por um único vírus (VSR com a gravidade de coinfecções. MÉTODOS: Este estudo avaliou uma coorte histórica de lactentes com infecção aguda por VSR. Secreção de nasofaringe foi coletada de todos os pacientes rotineiramente para pesquisa viral usando técnicas de biologia molecular. Os seguintes desfechos foram analisados: tempo total de internação, duração da oxigenioterapia, admissão em unidade de terapia intensiva e uso de ventilação mecânica. Os resultados foram ajustados para os fatores confundidores (prematuridade, idade e aleitamento materno. RESULTADOS: Foram incluídos no estudo 176 lactentes com idade média de 4,5 meses e diagnósticos de bronquiolite e/ou pneumonia. Cento e vinte e um tinham infecção única por VSR, e 55 tinham coinfecções (24 VSR + adenovírus, 16 VSR + metapneumovírus humano e 15 outras associações menos frequentes. Os quatro desfechos de gravidade avaliados foram semelhantes entre o grupo com infecção única por VSR e os grupos com coinfecções, independente do tipo de vírus associado com o VSR. CONCLUSÃO: As coinfecções virais não parecem alterar o prognóstico de lactentes hospitalizados com infecção aguda por VSR.

  12. PANORAMA LATINOAMERICANO DEL PAGO POR SERVICIOS AMBIENTALES

    Directory of Open Access Journals (Sweden)

    González T. Ángela

    2008-07-01

    Full Text Available Este documento busca proveer al lector de algunos elementos para el análisis y reflexión en torno al pago por servicios ambientales. Para ello, en primera instancia, aborda algunos conceptos básicos relacionados con economía ambiental, seguido de temas como la valoración económica de servicios ambientales y la implementación de mecanismos de pago por algunos de ellos. Lo anterior esta enriquecido con experiencias o estudios de caso a nivel latinoamericano y colombiano.

  13. Panorama latinoamericano del pago por servicios ambientales

    OpenAIRE

    González T., Ángela; Riascos A., Eliana

    2008-01-01

    Este documento busca proveer al lector de algunos elementos para el análisis y reflexión en torno al pago por servicios ambientales. Para ello, en primera instancia, aborda algunos conceptos básicos relacionados con economía ambiental, seguido de temas como la valoración económica de servicios ambientales y la implementación de mecanismos de pago por algunos de ellos. Lo anterior esta enriquecido con experiencias o estudios de caso a nivel latinoamericano y colombiano.

  14. Alarma activada por control remoto selectivo.

    OpenAIRE

    Eguíluz Morán, Luis Ignacio; Lara Santillán, Pedro María; Mañana Canteli, Mario

    1995-01-01

    La finalidad de esta invención consiste en disponer de una alarma que bien evite el robo de objetos ligeros y portátiles por el procedimiento que se conoce como "del tirón" --es decir, arrebatar algo y salir corriendo--, bien permita identificar un equipaje entre otros. La originalidad del dispositivo reside en la activación/desactivación del dispositivo de sonido por control remoto, así como la posibilidad de seleccionar el sonido de salida dependiendo de su finalidad. Se reivindica como de ...

  15. Alimentos industrializados mais consumidos por idosos hipertensos

    OpenAIRE

    Rockenbach, Aline; Blasi, Tereza Cristina; Blümke, Adriane Cervi

    2013-01-01

    Este estudo compreende a avaliação da quantidade de alimentos industrializados consumida por idosos hipertensos. Para tanto, 112 voluntários, de ambos os gêneros, residentes na área urbana de um município da região central do estado do Rio Grande do Sul, foram avaliados por meio de frequência alimentar e de um questionário socioeconômico, tendo a coleta se efetivado nos respectivos domicílios. Dentre os achados, verificou-se que 67% (n=75) eram do gênero feminino e 33% (n=37), do gênero mascu...

  16. Neumopericardio debido a herida por arma blanca

    Directory of Open Access Journals (Sweden)

    Samuel I. Merino Barrera

    2015-10-01

    Full Text Available Hombre de 24 años de edad que ingresó en el hospital debido a una herida por arma blanca penetrante en el hemitórax derecho. La herida, de 3 cm a nivel de la piel, se localizaba a nivel del segundo espacio intercostal derecho y la radiografía de tórax demostró un neumotórax del mismo lado y una colección radiotransparente, por debajo del pericardio parietal, desde el origen de los grandes vasos hasta la porción apical del ventrículo izquierdo.

  17. Leituras de Camilo Pessanha por estudantes chineses

    OpenAIRE

    Nobre, Cristina

    2017-01-01

    A comunicação Leituras de Camilo Pessanha por estudantes chineses parte das interpretações de poemas de Pessanha feitas por alunos dos cursos de Tradução e Interpretação Português-Chinês – Chinês-Português, Língua Portuguesa Aplicada e Língua e Cultura Portuguesas, da ESECS do IPL, durante os anos letivos de 2014-15 e 2015-16, para chegar a algumas caraterísticas culturais orientais da poesia de Clepsidra. Os poemas selecionados pelos estudantes foram: Viola chinesa; Branco e Vermelho; Ao lon...

  18. Conjuntivite presumível por Acanthamoeba

    OpenAIRE

    Ruthes,Ana Cristina de Carvalho; Wahab,Sâmia; Wahab,Najua; Moreira,Hamilton; Moreira,Luciane

    2004-01-01

    OBJETIVO: Abordar quatro casos de conjuntivite presumível por Acanthamoeba, descrevendo o diagnóstico, considerando sinais e sintomas e o tratamento instituído. MÉTODOS: Foram estudados casos de conjuntivite presumível por Acanthamoeba diagnosticados no Hospital de Olhos do Paraná (HOP), no período de setembro/1998 a janeiro/2002. Todos os olhos estudados foram submetidos a um protocolo de investigação que incluía exame oftalmológico completo, microbiologia e cultura de secreções conjuntivais...

  19. Acuerdo por la discreción

    Directory of Open Access Journals (Sweden)

    Yeny Serrano

    2006-01-01

    Full Text Available En este artículo se propone un análisis del texto del Acuerdo por la discreción firmado en 1999 por 32 directores de medios de comunicación para “elevar el nivel de calidad y responsabilidad en el cubrimiento y difusión de hechos violentos”. Se analizan los factores que impiden que este Acuerdo produzca cambios efectivos en la práctica profesional informativa y se presenta un modelo (Lemieux, 2000 que tiene en cuenta las variables que influyen en la producción del discurso informativo mediático.

  20. Demandas judiciais por medicamentos antineoplásicos: a ponta de um iceberg?

    Directory of Open Access Journals (Sweden)

    Thaís Jeronimo Vidal

    Full Text Available Resumo Ações judiciais com medicamentos antineoplásicos geram custos elevados aos governos e demandam análises criteriosas para garantir resultados eficientes e adequados em saúde. Este trabalho analisou processos enviados por entes federados a um instituto referência no tratamento de câncer para emissão de parecer técnico. Coletou-se dados das cópias dos processos analisados entre julho e dezembro/2013 e avaliou-se: subgrupos terapêuticos, presença em lista de medicamentos essenciais, registro sanitário, indicação off label, indicações constantes em diretrizes clínicas, incorporação do medicamento no sistema público de saúde e valor estimado das causas. Foram examinados 158 processos, com 164 solicitações de 35 antineoplásicos. A maioria dos medicamentos eram inibidores da tirosinoquinase, dez figuravam em lista de medicamentos essenciais, três não continham registro sanitário, dez tinham indicação de uso off label, 56,7% estavam descritas em diretrizes clínicas, quatro tinham recomendação para incorporação e o valor estimado das causas foi de R$ 18.110.504,89. Identificou-se que os instrumentos técnico-sanitários disponíveis para subsidiar as decisões parecem ser insuficientes e que há a necessidade de se estabelecer estratégias para minimizar o comprometimento da integralidade do cuidado.

  1. XPS analysis of nanocomposite Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}(C{sub 13}H{sub 11}N{sub 2}){sub y} films

    Energy Technology Data Exchange (ETDEWEB)

    Silipigni, L., E-mail: lsilipigni@unime.it [Dipartimento di Fisica e di Scienze della Terra, Università di Messina, V.le F.Stagno d’Alcontres 31, I-98166 Messina (Italy); Schirò, L., E-mail: lschiro@unime.it [Dipartimento di Fisica e di Scienze della Terra, Università di Messina, V.le F.Stagno d’Alcontres 31, I-98166 Messina (Italy); Scolaro, L. Monsù, E-mail: lmonsu@unime.it [Dipartimento di Scienze Chimiche, Università di Messina, Salita Sperone 31, I-98166 Messina (Italy); De Luca, G., E-mail: delucag@unime.it [Dipartimento di Scienze del Farmaco e Prodotti per la Salute, V.le Annunziata, I-98168 Messina (Italy); Salvato, G., E-mail: salvato@me.cnr.it [CNR-IPCF Istituto per i Processi Chimico-Fisici, V.le F. Stagno d’Alcontres 37, I-98158 Messina (Italy)

    2013-09-01

    Intercalation of 9-aminoacridine (9AA: C{sub 13}H{sub 10}N{sub 2}) in thin films of exfoliated Li{sub 2x−y}Mn{sub 1−x}PS{sub 3} has been performed by means of a solution approach starting from the hydrochloride salt of the organic species (9AAHCl: C{sub 13}H{sub 10}N{sub 2}·HCl). The resulting nanocomposite Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}(C{sub 13}H{sub 11}N{sub 2}){sub y} films have been investigated by X-ray photoemission spectroscopy (XPS), at room temperature, in the regions of the Mn, P, S and Cl 2p, Li, C and N 1s and Mn 3p core levels. The XPS analysis has been also carried out on the 9-aminoacridine hydrochloride films whose XPS spectra have been compared with those of the Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}(C{sub 13}H{sub 11}N{sub 2}){sub y} films to obtain information about the nature of the interaction between the guest species (9AAH{sup +}) and the matrix (Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}{sup −}).

  2. Pedro Teixeira y su viaje por Mesopotamia

    Directory of Open Access Journals (Sweden)

    Fuente del Pilar, José Javier

    2005-04-01

    Full Text Available Pedro Teixeira es un integrante notable de la ilustre nómina de los viajeros portugueses que, a finales del s, XVI y principios del XVII, ensancharon para Occidente las fronteras del mundo. Su conocimiento en España se debe a la publicación en 1994 de su obra «Relaciones del Origen, Descendencia y Sucesión de los Reyes de Persia, y de Harmuz, y de un viaje hecho por el autor dende la India hasta Italia por tierra», en edición realizada por el profesor Eduardo Barajas Sala, lamentablemente fallecido en 1997. En este artículo se ofrece una reseña biográfica de Pedro Teixeira, y un análisis del viaje narrado por el autor en la última parte de sus «Relaciones »: el que desde Ormuz le conducirá, a través de Mesopotamia, hasta la costa del Mediterráneo.…

  3. Osteomielitis esternal y escrofuloderma por vacuna BCG.

    Directory of Open Access Journals (Sweden)

    Ivohne Fernanda Corrales

    2003-06-01

    Full Text Available La vacuna BCG se ha usado en todo el mundo desde principios del siglo XX para la prevención de la tuberculosis. Se describe el caso de una niña de 13 meses de edad, previamente sana, que consultó por una masa esternal. El estudio radiológico mostró erosión perióstica. La lesión fue resecada y en la histopatología se encontró una reacción inflamatoria crónica con granulomas caseificantes con compromiso óseo y cutáneo. Se realizó una amplificación por PCR con iniciadores específicos de Mycobacterium tuberculosis del ADN obtenido a partir del tejido incluido en parafina, cuyo resultado fue negativo. Los antecedentes de vacunación con BCG, la aparición de este tipo de granulomas y la ausencia de ADN de M. tuberculosis en el tejido resecado apoyan el diagnóstico de osteomielitis esternal y escrofuloderma por BCG. La osteomielitis es una complicación infrecuente de la vacunación por BCG, que puede presentarse especialmente en pacientes inmunosuprimidos. La evolución clínica de la paciente no ha demostrado ninguna forma de inmunodeficiencia.

  4. Terceiro Setor: panorama das tendências de 1998 a 2013 por meio de um estudo bibliométrico

    Directory of Open Access Journals (Sweden)

    Bruna Altoe Marques

    2015-08-01

    Full Text Available O terceiro setor tem ganhado, nos últimos anos, expressiva atenção tanto da mídia quanto de inúmeros pesquisadores, possivelmente por causa de seu crescimento e importância social, sobretudo no sentido de suprir certas lacunas deixadas pelo Estado. Assim, o presente estudo tem como objetivo identificar as características dos artigos científicos sobre o terceiro setor publicados em congressos e periódicos nacionais nos anos de 1998 a 2013. A população do estudo foi composta por 115 artigos científicos analisados por meio de uma pesquisa descritiva com dados secundários, tratados através da técnica de pesquisa bibliométrica e análise de conteúdo. Os resultados são: os artigos sobre Terceiro Setor são predominantemente exploratórios, com estudos de caso e são qualitativos; a principal fonte de coleta de dados foi secundária, sendo a técnica mais utilizada para coletá-los a pesquisa documental e análise de conteúdo; a maioria dos artigos se destina aos usuários internos; em relação aos principais resultados identificados nas pesquisas parece existir dificuldades por parte das entidades do terceiro setor, especialmente na consolidação de modelos de gestão. Há também, destaque para a questão do disclosure social que segundo os estudos tem relação direta com a captação dos recursos; destaca-se que algumas áreas de preocupação permeiam as conclusões dos autores. Dentre elas: gestão com base em instrumentos aperfeiçoados; maior aderência às práticas contábeis como forma de melhor apresentar e estruturar as informações para a sociedade; e mecanismos de controle e gestão e a necessidade de apresentar/informar melhor os usuários/doadores por meio do disclosure contábil.

  5. Wettability and XPS analyses of nickel–phosphorus surfaces after plasma treatment: An efficient approach for surface qualification in mechatronic processes

    Energy Technology Data Exchange (ETDEWEB)

    Vivet, L., E-mail: laurent.vivet@valeo.com [Valeo, Group Electronic Expertise and Development Services, 2 rue André Boulle 94 046 Créteil (France); Joudrier, A.-L.; Bouttemy, M.; Vigneron, J. [Institut Lavoisier de Versailles, UMR CNRS 8180, 45 Avenue des Etats-Unis, 78035 Versailles (France); Tan, K.L.; Morelle, J.M. [Valeo, Group Electronic Expertise and Development Services, 2 rue André Boulle 94 046 Créteil (France); Etcheberry, A. [Institut Lavoisier de Versailles, UMR CNRS 8180, 45 Avenue des Etats-Unis, 78035 Versailles (France); Chalumeau, L. [Egide, Site industriel du Sactar, 85500 Bollène (France)

    2013-06-01

    Electroless nickel-high-phosphorus Ni–P plating is known for its physical properties. In case of electronic and mechatronic assembly processes achieved under ambient conditions the wettability of the Ni–P layer under ambient temperature and ambient air stays a point of surface quality investigation. This contribution will be devoted to the study of the surface properties of Ni–P films for which we performed air plasma treatment. We focus our attention on the evolution of the surface wettability, using the classical sessile drop technique. Interpreting the results with the OWRK model we extract the polar and disperse surface tension components from which we deduced typical evolution of the surface properties with the different treatment settings. By controlling the variations of the parameters of the plasma exposure we are able to change the responses of our Ni–P sample from total hydrophobic to total hydrophilic behaviours. All the intermediate states can be reached by adapting the treatment parameters. So it is demonstrated that the apparent Ni–P surface properties can be fully adapted and the surface setting can be well characterized by wettability measurements. To deep our knowledge of the surface modifications induced by plasma we performed parallel SEM and XPS analyses which provide informations on the structure and the chemical composition of the surface for each set of treatment parameters. Using this double approach we were able to propose a correlation between the evolution of surface chemical composition and surface wettability which are completely governed by the plasma treatment conditions. Chemical parameters as the elimination of the carbon contamination, the progressive surface oxidation, and the slight incorporation of nitrogen due to the air plasma interaction are well associated with the evolution of the wettability properties. So a complete engineering for the Ni–P surface preparation has been established. The sessile drop method can

  6. Wettability and XPS analyses of nickel–phosphorus surfaces after plasma treatment: An efficient approach for surface qualification in mechatronic processes

    International Nuclear Information System (INIS)

    Vivet, L.; Joudrier, A.-L.; Bouttemy, M.; Vigneron, J.; Tan, K.L.; Morelle, J.M.; Etcheberry, A.; Chalumeau, L.

    2013-01-01

    Electroless nickel-high-phosphorus Ni–P plating is known for its physical properties. In case of electronic and mechatronic assembly processes achieved under ambient conditions the wettability of the Ni–P layer under ambient temperature and ambient air stays a point of surface quality investigation. This contribution will be devoted to the study of the surface properties of Ni–P films for which we performed air plasma treatment. We focus our attention on the evolution of the surface wettability, using the classical sessile drop technique. Interpreting the results with the OWRK model we extract the polar and disperse surface tension components from which we deduced typical evolution of the surface properties with the different treatment settings. By controlling the variations of the parameters of the plasma exposure we are able to change the responses of our Ni–P sample from total hydrophobic to total hydrophilic behaviours. All the intermediate states can be reached by adapting the treatment parameters. So it is demonstrated that the apparent Ni–P surface properties can be fully adapted and the surface setting can be well characterized by wettability measurements. To deep our knowledge of the surface modifications induced by plasma we performed parallel SEM and XPS analyses which provide informations on the structure and the chemical composition of the surface for each set of treatment parameters. Using this double approach we were able to propose a correlation between the evolution of surface chemical composition and surface wettability which are completely governed by the plasma treatment conditions. Chemical parameters as the elimination of the carbon contamination, the progressive surface oxidation, and the slight incorporation of nitrogen due to the air plasma interaction are well associated with the evolution of the wettability properties. So a complete engineering for the Ni–P surface preparation has been established. The sessile drop method can

  7. Gold deposition on pyrite and the common sulfide minerals: An STM/STS and SR-XPS study of surface reactions and Au nanoparticles

    Science.gov (United States)

    Mikhlin, Yuri L.; Romanchenko, Alexander S.

    2007-12-01

    Gold species spontaneously deposited on pyrite and chalcopyrite, pyrrhotite, galena, sphalerite from HAuCl 4 solutions at room temperature, as well as the state of the reacted mineral surfaces have been characterized using synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS), scanning tunneling microscopy and tunneling spectroscopy (STM/STS). The deposition of silver from 10 -4 M AgNO 3 has been examined for comparison. Gold precipitates as metallic nanoparticles (NPs) from about 3 nm to 30 nm in diameter, which tends to aggregate forming larger particles, especially on pyrite. The Au 4f binding energies increase up to 1 eV with decreasing size of individual Au 0 NPs, probably due to the temporal charging in the final state. Concurrently, a positive correlation between the tunneling current and the particle size was found in STS. Both these size effects were observed for unusually large, up to 20 nm Au particles. In contrast, silver deposited on the minerals as nanoparticles of semiconducting sulfide showed no shifts of photoelectron lines and different tunneling spectra. The quantity of gold deposited on pyrite and other minerals increased with time; it was lower for fracture surfaces and it grew if minerals were moderately pre-oxidized, while the preliminary leaching in Fe(III)-bearing media inhibited the following Au deposition. After the contact of polished minerals with 10 -4 M AuCl4- solution (pH 1.5) for 10 min, the gold uptake changed in the order CuFeS 2 > ZnS > PbS > FeAsS > FeS 2 > Fe 7S 8. It was noticed that the open circuit (mixed) potentials of the minerals varied in approximately the same order, excepting chalcopyrite. We concluded that the potentials of minerals were largely determined by Fe(II)/Fe(III) couple, whereas the reduction of gold complexes had a minor effect. As a result, the deposition of gold, although it proceeded via the electrochemical mechanism, increased with decreasing potential. This suggests, in particular, that the

  8. Sentidos do diagnóstico por câncer de mama feminino para casais que o vivenciaram

    Directory of Open Access Journals (Sweden)

    Cintia Bragheto Ferreira

    2008-12-01

    Full Text Available A lacuna de compreensão dos sentidos construídos por casais que vivenciaram o câncer de mama da parceira motivou a realização deste estudo, que objetivou descrever e analisar os sentidos que casais constroem sobre o câncer de mama da parceira e sobre as formas de se relacionar com esse adoecimento. Sete casais foram entrevistados e os dados coletados foram analisados à luz do referencial teórico do construcionismo social. Os resultados mostraram que os sentidos de provação e morte construídos para o câncer da parceira, despertaram nos participantes sentimentos de revolta e ansiedade e a relação com Deus. A partir disso, propõe-se a relevância da assistência interdisciplinar para esses casais, bem como a integração do discurso religioso como ferramenta do cuidado assistencial a essa população.

  9. IDENTIFICANDO OPORTUNIDADES DE MELHORIA NO PROCESSO DE ALTA DO PACIENTE DE MATERNIDADE POR MEIO DO LEAN HEALTHCARE

    Directory of Open Access Journals (Sweden)

    Marlon Soliman

    2017-12-01

    Full Text Available O Lean Healthcare é uma metodologia de gestão focada no paciente e na cooperação entre os seus participantes que busca a melhoria contínua ao eliminar desperdícios agregando assim, mais valor aos processos hospitalares. Considerando as variadas oportunidades de aplicação dessa filosofia, levando em conta que o Lean Healthcare começou a ser aplicado recente, essa pesquisa buscou analisar o processo de alta hospitalar em uma maternidade de um hospital de grande porte com o objetivo de aumentar o disponibilidade do leito de internação, visto que esse setor repetidas vezes apresenta um quadro de superlotação. Por meio de observações não participantes campo e diagnóstico da situação atual, foram analisados os principais desperdícios encontrados no processo de alta. Os desperdícios encontrados foram classificados de acordo com as sete perdas da produção enxuta e com o impacto que causam no valor do paciente. Em seguida, ações de contramedidas foram propostas pelos autores. Essas ações focam no nivelamento do fluxo de pacientes, visto que atualmente as altas médicas ocorrem em lotes e com isso ocorre um acúmulo de tarefas nas atividades seguintes o que aumenta o tempo de reocupação dos leitos liberados

  10. Suicídio e o jogo da Baleia Azul analisados na perspectiva de Anomia de Émile Durkheim

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    Irineu Francisco Barreto Junior

    2017-06-01

    Full Text Available Este artigo apresenta uma síntese das principais ideias de Durkheim, representante da sociologia positivista. São revisitados os conceitos de fato social, solidariedade e anomia com o intuito de analisar os suicídios ocorridos no ano de 2017 e associados ao jogo da Baleia Azul, fenômeno mundial da internet e da Sociedade da Informação. O conceito de anomia pode ser compreendido como ausência de normas, que decorre de grande turbulência social, heteronomia, perda dos laços sociais e de solidariedade. Nessa perspectiva, o artigo problematiza a associação entre o conceito de suicídio anômico e as mortes associadas ao jogo da Baleia Azul.

  11. CARTAS PARA O FÛHRER: A POPULARIDADE DO PARTIDO NAZISTA ANALISADO PELAS SUAS CORRESPONDÊNCIAS

    Directory of Open Access Journals (Sweden)

    Pedro Chaves Lima

    2017-04-01

    Full Text Available O artigo tem como objetivo medir o índice de popularidade de Hitler e do Partido Nacional-Socialista (Partido Nazista a partir das correspondências encaminhadas ao Füher nos anos de 1933-1938, reunidas no livro Cartas para Hitler, de Henrik Eberle. As cartas, que expressam os sentimentos, ideias, posições e os mais diversos desejos de cidadãos comuns aos mais altos condecorados militares alemães, foram analisadas a partir da perspectiva quanti-qualitativa, como forma de conhecer os motivos das queixas e elogios dos alemães ao nazismo. As cartas foram um dos meios de compreender de forma mais profunda, como a sociedade via, aceitava ou negligenciava seu líder.

  12. Os Antecedentes do Consumo de Produtos Culturais por Consumidores de Baixa Renda

    Directory of Open Access Journals (Sweden)

    Alexandre Rabêlo Neto

    2014-03-01

    Full Text Available Esta pesquisa teve como objetivo geral analisar as relações entre as variáveis influenciadoras e o consumo de produtos culturais por consumidores de baixa renda, considerando o modelo adaptado de Leocádio (2008. Nesse contexto, buscou-se identificar as variáveis que explicam o consumo de produtos culturais; identificar os perfis de consumidores de acordo com os antecedentes de consumo de produtos culturais; avaliar a relação entre o nível de vivências em manifestações artísticas e o consumo de produtos culturais; avaliar a relação entre o perfil da renda do consumidor e o consumo de produtos culturais; avaliar a relação entre o perfil de capital cultural do consumidor e o consumo de produtos culturais; verificar as relações entre os antecedentes, conforme o modelo adaptado de Leocádio (2008 que influenciam o consumo de produtos culturais. Apresentou-se um modelo que integra os antecedentes de consumo cultural. Utilizou-se o Survey como método, aplicado a 556 respondentes, em 31 bairros da cidade de Fortaleza, consumidores de produtos culturais de baixa renda. Foram utilizadas técnicas de análise de dados multivariadas por meio de análise fatorial, além da modelagem de equações estruturais utilizando-se o software Smartpls 2.0. Os antecedentes que apresentaram relação com o consumo foram: capital cultural, preferência e a influência dos grupos de referência. O modelo estrutural analisado demonstrou que inovatividade, acesso aos instrumentos de consumo e vivências em manifestações artísticas influenciam a preferência e não tem relação com o consumo de produtos culturais. DOI: 10.5585/remark.v13i1.2320

  13. Gerenciamento de medicamentos em desuso devolvidos por pacientes ambulatoriais de um hospital universitário

    Directory of Open Access Journals (Sweden)

    Lilian Pereira Primo

    2014-04-01

    Full Text Available O presente trabalho teve como objetivo avaliar o perfil das devoluções de medicamentos não utilizados à farmácia do Componente Especializado da Assistência Farmacêutica do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, da Universidade de São Paulo, bem como o perfil de sua destinação final. Tratase de um estudo transversal e descritivo que teve como ferramenta a coleta dos seguintes dados: identificação do paciente ou responsável, motivo da devolução e dados dos medicamentos devolvidos (lote, validade, quantidade devolvida e condições de armazenamento. Realizou-se a análise dos dados por meio de avaliação do questionário aplicado e, além disso, avaliou-se o aspecto visual dos medicamentos devolvidos que foram classificados como aptos para reuso por outros pacientes ou enviados para descarte. Os custos relacionados com as devoluções à instituição foram calculados e analisados. A coleta de dados foi realizada no mês de julho de 2011. Durante este período, foram recebidas 34 devoluções, correspondendo a 2149 unidades de medicamentos. Destes, 82,4% estavam íntegros, 6,0% eram termolábeis e apenas 3,0% estavam vencidos, sendo reaproveitados 76,5% de todos os medicamentos. O valor financeiro do total dos itens devolvidos foi de R$ 5.759,90 e a economia com o repasse a outros pacientes representou R$ 4.743,34. O estímulo à devolução a partir da implementação de um sistema de gerenciamento de medicamentos efetivo oferece segurança ao paciente e ao meio ambiente e economia ao sistema de saúde. Para que isso ocorra, a equipe de saúde deve estar capacitada a orientar sobre o armazenamento correto a fim de garantir a integridade e qualidade do princípio ativo, visando um resultado terapêutico ótimo àqueles pacientes que reutilizarem os mesmos.

  14. Precisão diagnóstica das doenças cirúrgicas nos exames por congelação

    Directory of Open Access Journals (Sweden)

    Rafael Denadai Pigozzi da Silva

    Full Text Available OBJETIVO: Avaliar o grau de precisão diagnóstica dos exames por congelação em diferentes sítios anatômicos realizados em um serviço universitário de patologia. MÉTODOS: Foi realizado estudo retrospectivo a partir de banco de dados informatizado de todos os exames por congelação. Estes diagnósticos foram comparados com os definitivos em parafina, utilizados como controles. Os exames foram distribuídos em três grupos: inconclusivos, concordantes e não concordantes, sendo este último subdivido em falsos positivos e falsos negativos. As principais indicações dos exames e os sítios anatômicos envolvidos com as divergências diagnósticas também foram analisados. RESULTADOS: Quatrocentas e trinta e três peças cirúrgicas foram submetidas a exames por congelação, sendo a principal indicação o diagnóstico da lesão (75,75%. Em 404 exames (93,30% os diagnósticos das biópsias por congelação e em parafina foram concordantes. Em 20 (4,62% casos os resultados das biópsias por congelação foram inconclusivos e em nove (2,08% ocorreram falsos negativos. Não houve resultados falsos positivos. O principal órgão avaliado foi a tireoide (25,64%. Na análise global, a região do corpo mais relacionada com os diagnósticos inconclusivos por congelação foi a tireoide (sete casos e em relação aos sítios específicos foram os pulmões/pleura/mediastino (13,33%. Pele foi o órgão que mais apresentou diagnósticos discordantes entre biópsias por congelação e em parafina. CONCLUSÃO: A acurácia da congelação de forma global foi de 93,30%; por sítios anatômicos específicos, a precisão diagnóstica variou de 86,67% a 100%.

  15. NEGOCIACIÓN: COMPETENCIA GERENCIAL POR ANTONOMASIA

    Directory of Open Access Journals (Sweden)

    Jorge Ignacio Paz

    Full Text Available Los conflictos son inherentes al ser humano y surgen cuando las personas se relacionan e interactúan, cuando manejan posiciones contrarias, las sostienen y las defienden. Las buenas decisiones surgen de la creatividad por el desacuerdo. Negociar es redefinir el problema para generar la mejor opción que satisfaga los intereses de las partes y, en consecuencia, éstas puedan comprometerse en un acuerdo que puedan cumplir. Dentro de la nueva concepción de la gerencia como suministradora de conocimientos para generar resultados, la competencia de negociación ha venido adquiriendo un gran protagonismo e importancia, esencialmente por constituirse en la herramienta fundamental para la solución de conflictos y para el establecimiento y mantenimiento de relaciones perdurables.

  16. Mastite por Paracoccidioidomicose: Relato de Caso

    Directory of Open Access Journals (Sweden)

    Chambô Filho Antônio

    2000-01-01

    Full Text Available A paracoccidioidomicose é uma importante micose sistêmica, endêmica na América Latina. A infecção é usualmente adquirida por inalação das partículas do micélio. Na sua maioria são infecções assintomáticas e estão associadas a vários fatores do hospedeiro, como sexo, idade, fatores genéticos, bem como às características do agente infeccioso e sua virulência. Apresentamos um caso de mastite por paracoccidioidomicose, com o objetivo de demonstrar que pacientes idosas e com abcessos na mama devem ser submetidas à biópsia.

  17. Celulitis por cuerpo extraño

    Directory of Open Access Journals (Sweden)

    Miguel B. Carrasco Guzmán

    2016-01-01

    Full Text Available Las infecciones de la piel y el tejido celular subcutáneo surgen como un grupo importante de afecciones con una alta morbilidad en edades pediátricas, generalmente relacionada con traumatismo y cuerpos extraños. Se presenta el caso de una escolar femenina de 6 años de edad, con síntomas y signos clínicos que sugieren celulitis en el muslo derecho,  por su evolución tórpida se le realizó el estudio ultrasonográfico que confirmó el diagnóstico etiológico de una celulitis secundaria a un traumatismo, provocada por la introducción de un gran cuerpo extraño, que pasó inadvertido para a familia de la menor.

  18. Representações sociais do alcoolismo construídas por não-alcoolistas

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo Silva Souza

    2015-07-01

    Full Text Available http://dx.doi.org/10.5007/2178-4582.2015v49n1p49 A compreensão das crenças sobre o “alcoolismo” pode ser importante para a implantação de políticas e práticas de saúde. Esta pesquisa investigou as representações sociais do alcoolismo construídas por não-alcoolistas brasileiros. Cinquenta adultos participaram deste estudo, 27 mulheres e 23 homens. Eles responderam a entrevistas semiestruturadas que abordaram crenças sobre o alcoolismo, atribuição causal, possíveis tratamentos e o alcoolista que não quer se tratar. Os dados foram analisados com análise de conteúdo temática. Os participantes representaram o alcoolismo como doença e vício, resultado de uma fraqueza inerente ao alcoolista, causado principalmente por problemas psicológicos. Sugeriram que a “força de vontade”, os Alcoólicos Anônimos e a internação são as principais formas de tratamento. As representações do alcoolismo ancoraram em noções sobre moralidade e fracasso individual. A lógica da redução de danos parece não estar incorporada à cultura brasileira apesar de ser diretriz oficial para o cuidado em saúde.

  19. Monitoramento do percevejo marrom Euschistus heros (Hemiptera: Pentatomidae por feromônio sexual em lavoura de soja

    Directory of Open Access Journals (Sweden)

    Valvenarg Pereira da Silva

    2014-11-01

    Full Text Available O objetivo deste trabalho foi avaliar a eficiência das formulações septo de borracha e lure do feromônio sexual do percevejo marrom Euschistus heros e compará-la ao método do pano de batida, para o monitoramento dessa praga em lavoura de soja. Os tratamentos foram: feromônio em septo de borracha, feromônio em lure e amostragem com pano de batida. As amostragens foram realizadas semanalmente durante a fase reprodutiva da soja (dez semanas. Para estimar a densidade populacional de percevejos e compará-la à captura nas armadilhas de feromônio, foram efetuados quatro panos de batida por semana em todas as parcelas; além disso, foi determinado o número de percevejos capturados nas armadilhas por semana. Os danos provocados pelos percevejos nas sementes foram analisados pelo teste de tetrazólio. As formulações do feromônio foram eficientes na captura de E. heros, e a formulação em lure capturou mais percevejos. O controle precoce da população, indicado pelo nível de controle nas armadilhas com feromônio, resultou em sementes com maior qualidade do que as provenientes das parcelas monitoradas pelo pano de batida. Assim, as armadilhas com feromônio são mais eficientes que o pano de batida para o monitoramento das populações de percevejos durante a fase crítica do ataque deste inseto nas lavouras de soja.

  20. Por las carreteras de la Libertad

    OpenAIRE

    Cailloma Navarrete, Gerardo; Cailloma Navarrete, Gerardo

    2014-01-01

    Por qué en La Libertad, una región con un canon minero de 415 millones de soles y con un presupuesto para el año fiscal 2013 que asciende a más de mil millones y medio de soles tiene una red de carreteras tan deficientes? Cada viaje se convierte así en una aventura de la que no sabes si vas a volver con vida. Este es un testimonio de Gerardo Cailloma

  1. Amar por cartas - este inferno de amara

    Directory of Open Access Journals (Sweden)

    Matildes Demetrio dos Santos

    1999-10-01

    Full Text Available Este trabalho tem por objetivo estudar o amor nas Folhas caídas e nas Cartas de amor à Viscondessa da Luz, de Almeida Garrett.Seus poemas cheios de erotismo e sensua lidade, inspirados numa mulher casada, Rosa Montúrar Infante, escandalizaram a sociedade portuguesado sécu lo XIX. Suas cartas de amor, em segredo, criavam uma ficção de características místicas.

  2. Leibniz damnificado por el terremoto de Lisboa

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    Evaristo ÁLVAREZ MUÑOZ

    2009-11-01

    Full Text Available RESUMEN: En las páginas que siguen se argumenta que al filósofo alemán Gottfried Wilhelm Leibniz —fallecido en Hannover en 1716— o, al menos, a su obra Teodicea, cabría contarlos, echadas las cuentas de la manera que se verá, entre las víctimas del terremoto de Lisboa de 1755. Asimismo se subraya la persistencia del pensamiento de Leibniz en las respuestas dadas por los filósofos del siglo XVIII al trágico suceso. Se estudian las reacciones de Voltaire, de Rousseau y de Kant ante los estragos provocados por el seísmo y se concluye que las manifestaciones de los dos primeros ya habían sido previstas en Teodicea e, incluso, la vía científica pretendida por Kant había sido abierta en Protogaea.ABSTRACT: It is argued here that German philosopher Gottfried Wilhelm Leibniz, passed away in 1716, and, specially, that his work Teodicea, could be considered amongst the victims of the Lisbon earthquake of 1755. The persistence of the Leibniz’s thought in the answers given by the philosophers of the 18th Century to the tragic event is also emphasized. Voltaire and Rousseau’s reactions to the damage caused by the earthquake had been anticipated in Teodicea and the scientific way followed by Kant had been initiated in Protogaea.

  3. Abscesso esplênico causado por Salmonella

    Directory of Open Access Journals (Sweden)

    Bruno von Glen Herkenhoff

    Full Text Available OBJETIVO: Relatar as características demográficas, clínicas, diagnóstica e terapêutica de pacientes com abscesso esplênico (AE causado por Salmonella. MÉTODO: Análise retrospectiva de dados de pacientes atendidos no Serviço de Cirurgia Geral e Aparelho Digestivo do Hospital Universitário Gaffrée-Guinle no período de janeiro de 2001 a dezembro de 2005, a estes se incluiu um caso tratado em outro hospital em época anterior. RESULTADOS: Dentre 4823 pacientes recentemente atendidos, dois apresentaram AE causado por Salmonella enteritidis, enquanto o caso mais antigo o agente responsável foi a Salmonella typhi. Todos eram homens, com idade média de 45 anos. Em nenhum deles foi identificada condição predisponente à formação do abscesso; os exames de imagem foram capazes de diagnosticar o AE. Todos foram tratados por esplenectomia e antibioticoterapia e evoluíram para cura. CONCLUSÕES: A Salmonella, apesar de infrequente, pode ser o agente causal do AE. Caracteristicamente os abscessos eram grandes e apresentavam material necrótico em seu interior. Nesta condição, a esplenectomia associada a antibioticoterapia mostrou-se eficaz no tratamento.

  4. Eritema multiforme mayor desencadenado por antimicrobianos

    Directory of Open Access Journals (Sweden)

    Ronaldo de Carvalho Raimundo

    2010-03-01

    Full Text Available El eritema multiforme, aparece como una enfermedad sistémica con la participación de la piel y las membranas mucosas en relación con varios factores como las infecciones bacterianas o virales, y en particular la administración de drogas, analgésicos y antibióticos en general. Se presenta un paciente masculino de 29 años de edad con eritema multiforme mayor desencadenado por antimicrobianos con la aparición de lesiones vesiculares-bulloso-ulcerosas en las regiones de los labios, encías, la lengua y la mucosa genital en tratamiento de una infección del tracto urinario con norfloxacino 400 mg por una semana. Fue realizado un tratamiento de soporte con el uso de colutorios para la higienización bucal y pomada a base de corticoide para protección de las úlceras, antihistamínicos y orientación nutricional de dieta líquida hipercalórica e hiperproteica. Este síndrome está caracterizado como un proceso eruptivo buloso agudo que compromete la calidad de vida del paciente y no hay pruebas de laboratorio específicas por lo que su diagnóstico debe estar basado en la revisión minuciosa de la anamnesis y en los hallazgos clínicos.

  5. A transferência do poder no império romano: a sucessão de Nerva por Trajano

    Directory of Open Access Journals (Sweden)

    Alex Aparecido da Costa

    2013-01-01

    Full Text Available O problema da questão sucessória durante o Alto Império romano chama-nos a atenção, sobretudo, pelo fato de que no período as mudanças dos césares acarretaram não só distúrbios políticos e conflitos militares, elas impuseram também problemas de legitimação que buscaram respaldo nas instituições tradicionais por conta da escassez de mecanismos jurídicos que as amparassem. No caso analisado neste artigo, a partir do estudo do Panegírico de Trajano de Plínio, o Jovem, com o auxílio de uma análise comparativa dos casos da sucessão de Augusto por Tibério e da tentativa de sucessão de Galba por Pisão Liciniano, percebemos que o sucesso de uma solução pacífica obtida através da passagem do poder de Nerva a Trajano por meio da adoção simbolizou o abandono de dois recursos, o dinástico tradicional, e o restrito à aristocracia de Roma e introduziu a opção da escolha do governante para além das fronteiras da Itália. Assim a presença de Trajano como primeiro provincial a tornar-se imperador representou a renúncia de um sistema que reservava o poder aos indivíduos do centro do império e também o fortalecimento político de camadas mais vastas das populações que viviam sob a égide de Roma.

  6. Alcoolismo feminino: início do beber alcoólico e busca por tratamento = Alcoholism in women: the beginning of drinking and the search for treatment

    Directory of Open Access Journals (Sweden)

    Assis, Dilma Franco Fátima de

    2010-01-01

    Full Text Available Objetivo: Conhecer o perfil, as circunstâncias do início do uso do álcool pela mulher alcoolista e as condições reguladoras da busca pelo tratamento. Métodos: Pesquisa com 15 mulheres de um Ambulatório de Saúde Mental, utilizando formulário estruturado e entrevista semiestruturada. Os dados foram analisados pela estatística descritiva e a análise das entrevistas baseada na técnica de análise de conteúdo. Resultados: Idades entre 40 a 49 anos; baixa escolaridade, solteiras, família variante e de baixa renda, não praticantes de atividade física e a maioria tabagistas (figuras de 1 a 5. Muitas iniciaram no uso de álcool na adolescência; outras, na vida adulta. Foram encaminhadas ao serviço ou procuraram espontaneamente por ele, com desejo de parar e/ou reduzir o uso e também por problemas associados. Conclusão: O uso nocivo de álcool demandará maiores reflexões diante dos múltiplos fatores que envolvem o fenômeno alcoolismo

  7. Mulheres em situação de violência pelo parceiro íntimo: tomada de decisão por apoio institucional especializado

    Directory of Open Access Journals (Sweden)

    Leônidas de Albuquerque Netto

    Full Text Available RESUMO Objetivo Propõe-se analisar fatores envolvidos na tomada de decisão de mulheres em situação de violência interpessoal, praticada pelo parceiro íntimo, na busca por apoio institucional de referência. Métodos Pesquisa qualitativa, descritiva e exploratória. Dezesseis mulheres foram entrevistadas, entre junho e setembro de 2012, em um Centro de Referência à Mulher de Duque de Caxias, Rio de Janeiro, Brasil, por meio de instrumento semiestruturado e individual. Os relatos foram analisados pelo método do Discurso do Sujeito Coletivo. Resultados As mulheres buscaram suporte psicossocial quando a violência interpessoal alcançou o limite da tolerância. Este suporte possibilitou o resgate da autoestima e da confiança, além da tomada de consciência para a necessidade de mudança de vida e de autonomia econômica. Conclusões As mulheres alcançaram sua autoconfiança com a superação da violência, o que possibilitou o resgate da autoestima e a tomada de decisão para a saída da situação de violência interpessoal praticada pelo parceiro íntimo.

  8. TIPOS POLÍNICOS COLETADOS POR Tetragonisca angustula (LATREILLE, 1811 EM UM FRAGMENTO DE FLORESTA ATLÂNTICA NO ESPÍRITO SANTO

    Directory of Open Access Journals (Sweden)

    Filipe Torres

    2015-06-01

    Full Text Available A identificação da dieta de abelhas é fundamental para o conhecimento da biologia e da ecologia destes insetos. Aqui apresentamos a identificação dos tipos polínicos coletados por Tetragonisca angustula em um fragmento de Floresta Atlântica no Espírito Santo. As amostras de pólen foram coletadas durante 12 meses no Parque Estadual da Cachoeira da Fumaça (PECF. Os indivíduos estudados foram capturados com rede entomológica e as pelotas de pólen foram removidas de suas corbículas. Para identificação dos tipos polínicos, os grãos de pólen foram acetolisados, montados em lâminas e analisados em microscopia de luz (ML. Foram identificados 32 tipos polínicos pertencentes a 16 famílias de angiospermas. Fabaceae e Myrtaceae apresentaram a maior riqueza de tipos polínicos, com cinco tipos cada. A maior diversidade de tipos polínicos foi encontrada nos meses de setembro e outubro. A diversidade de famílias botânicas visitadas por T. angustula confirma o hábito generalista desta espécie e permite verificar que o PECF é um importante refúgio para esta espécie de abelha nativa.

  9. Análise dos benefícios relacionais observados por usuários de serviços.

    Directory of Open Access Journals (Sweden)

    Márcio de Oliveira Mota

    2008-10-01

    Full Text Available Este estudo tem como objetivo analisar as relações entre os benefícios relacionaispercebidos por consumidores e seus antecedentes e conseqüentes no contexto deserviços. O estudo compreendeu uma pesquisa descritiva, do tipo survey, de naturezaquantitativa. A pesquisa de campo foi realizada com 415 consumidores queinformaram o tipo de serviço analisado. Os dados coletados foram submetidos atestes estatísticos por meio da técnica de modelagem em equações estruturais, nointuito de testar o modelo proposto. Ressalte-se o ineditismo do modelo proposto,pois, neste estudo, foi feita uma avaliação da relação dos benefícios relacionais eseus antecedentes e conseqüentes. Este estudo concluiu que os benefícios relacionaissão percebidos pelos consumidores independentemente do grau de customizaçãodos serviços ou da intensidade de contato. Foram encontradas significativasassociações entre satisfação com os empregados e os demais construtos, portantopôde-se inferir a importância do elo entre empregados e consumidores.

  10. Utilização dos equipamentos de proteção individual por mototaxistas: percepção dos fatores de risco e associados

    Directory of Open Access Journals (Sweden)

    Jules Ramon Brito Teixeira

    2014-04-01

    Full Text Available Este estudo objetivou analisar as práticas e percepções de mototaxistas a respeito do uso dos equipamentos de proteção individual (EPI por meio de pesquisa de campo, exploratório- descritiva, de abordagem qualitativa. Foram entrevistados trinta mototaxistas do Município de Jequié, Bahia, Brasil. Para a coleta dos dados, foi utilizada a entrevista semiestruturada, e, como instrumento, o questionário. Os dados foram analisados pela Análise de Conteúdo Temático. Os resultados evidenciaram: Categoria 1 – percepção de risco, subcategoria – condicionantes/determinantes para o uso do EPI; Categoria 2 – adesão, subcategoria – adesão ao uso do equipamento de proteção ocupacional; Categoria 3 – o uso do EPI como fator de proteção em acidentes no trânsito, subcategorias 1 – acidentes ocupacionais, 2 – uso do EPI no momento do acidente, 3 – não uso do EPI no momento do acidente. Por fim, tornou-se explícito que os mototaxistas têm algum conhecimento acerca dos equipamentos de proteção ocupacional e, inclusive, atribuem importância ao devido uso desses instrumentos, entretanto, nem sempre fazem o uso adequado deles.

  11. Uma investigação dos sentidos de um phrasal verb por meio dos corpora e dicionários on-line

    Directory of Open Access Journals (Sweden)

    Emiliana Fernandes Bonalumi

    2014-06-01

    Full Text Available Nesta pesquisa analisamos o uso do phrasal verbs throw up encontrado em dois corpora on-line originalmente escritos em língua inglesa, a saber: British National Corpus (BNC e Corpus of Contemporary American English (COCA, bem como no livro didático adotado em sala de aula New English File Upper-Intermediate, com o suporte dos dicionários on-line Cambridge Online Dictionary e Macmillan Dictionary. Objetivamos identificar, classificar e generalizar o uso e significados do phrasal verb selecionado para a análise nos respectivos corpora on-line em relação ao seu uso e significado no livro didático anteriormente mencionado. Por meio dos corpora e dicionários on-line, o aluno expandirá seu conhecimento acerca do uso e significados de um determinado phrasal verb, como o analisado nesta investigação. Palavras-chave: linguística de corpus; ensino movido por dados; phrasal verbs.

  12. Avaliação do metabolismo oxidativo e da histopatologia renal e hepática de ovinos intoxicados por cobre e tratados com tetratiomolibdato e vitaminas antioxidantes

    OpenAIRE

    Rebeca Alves Weigel

    2008-01-01

    Para avaliar o benefício da utilização parenteral das vitaminas C e/ou E associadas ao quelante de cobre, tetratiomolibdato de amônio (TTM), na recuperação de ovinos com intoxicação cumulativa por cobre (ICC), foram analisados os parâmetros vitais; o metabolismo oxidativo, através das concentrações séricas de ácido úrico e malondialdeído, atividade sanguínea da glutationa reduzida, habilidade de redução férrica plasmática, atividade urinária de N-acetil-β-D-glucosamidase; peso vivo, hema...

  13. DISTRIBUIÇÃO ESPACIAL DOS ACIDENTES POR ANIMAIS PEÇONHENTOS NO ESTADO DO RIO GRANDE DO NORTE-BRASIL NO PERÍODO DE 2001-2010

    OpenAIRE

    Isabelle Ribeiro Barbosa; Wilton Rodrigues de Medeiros; Íris do Céu Clara Costa

    2015-01-01

    O objetivo foi analisar a distribuição espacial dos acidentes por animais peçonhentos no estado do Rio Grande do Norte, buscando identificar o padrão dessa distribuição através de uma análise geoestatística. Foram analisados os 22.242 registros de casos ocorridos nos 167 municípios do estado no período de 2001 a 2010. Calculou-se a taxa média de incidência nos dez anos e analisou-se a distribuição espacial, a intensidade e a significância dos aglomerados através do índice de Moran Global, Mor...

  14. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

    Science.gov (United States)

    Gorasia, Dhana G; Veith, Paul D; Hanssen, Eric G; Glew, Michelle D; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C

    2016-08-01

    The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

  15. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

    Directory of Open Access Journals (Sweden)

    Dhana G Gorasia

    2016-08-01

    Full Text Available The type IX secretion system (T9SS has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

  16. XPS study of Li/Nb ratio in LiNbO{sub 3} crystals. Effect of polarity and mechanical processing on LiNbO{sub 3} surface chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Skryleva, E.A., E-mail: easkryleva@gmail.com; Kubasov, I.V., E-mail: kubasov.ilya@gmail.com; Kiryukhantsev-Korneev, Ph.V., E-mail: kiruhancev-korneev@yandex.ru; Senatulin, B.R., E-mail: borisrs@yandex.ru; Zhukov, R.N., E-mail: rom_zhuk@mail.ru; Zakutailov, K.V., E-mail: zakkonst@gmail.com; Malinkovich, M.D., E-mail: malinkovich@yandex.ru; Parkhomenko, Yu.N., E-mail: parkh@rambler.ru

    2016-12-15

    Highlights: • XPS Li/Nb ratio measurement uncertainty in LNbO3 specimens was obtained. • The effect of polarization on surface chemistry was observed only on cleaves. • Li/Nb ratio on positive cleave surface is higher than on negative one. • The positive cleave surface adsorbs fluorine more efficiently than negative one. • Mechanical processing of crystals reduces surface Li/Nb. - Abstract: Different sections of congruent lithium niobate (CLN) crystals have been studied using X-ray photoelectron spectroscopy (XPS). We have developed a method for measuring the lithium-to-niobium atomic ratio Li/Nb from the ratio of the Li1s and Nb4s spectral integral intensities with an overall error of within 8 %. Polarity and mechanical processing affect the Li/Nb ratio on CLN crystal surfaces. The Li/Nb ratio is within the tolerance (0.946 ± 0.074) on the negative cleave surface Z, and there is excess lithium (Li/Nb = 1.25 ± 0.10) on the positive surface. The positive surfaces of the 128° Y cut plates after long exposure to air exhibit LiOH formation indications (obvious lithium excess, higher Li1s spectral binding energy and a wide additional peak in the O1s spectrum produced by nonstructural oxygen). XPS and glow discharge optical electron spectroscopy showed that mechanical processing of differently oriented crystals (X, Z and 128° Y) and different polarities dramatically reduces the Li/Nb ratio. In situ fluorine adsorption experiments revealed the following regularities: fluorine adsorption only occurred on crystal cleaves and was not observed for mechanically processed specimens. Positive cleave surfaces have substantially higher fluorine adsorption capacity compared to negative ones.

  17. XPS-and-DFT analyses of the Pb 4f — Zn 3s and Pb 5d — O 2s overlapped ambiguity contributions to the final electronic structure of bulk and thin-film Pb-modulated zincite

    Energy Technology Data Exchange (ETDEWEB)

    Zatsepin, D.A. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation); Boukhvalov, D.W., E-mail: danil@hanyang.ac.kr [Department of Chemistry, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Theoretical Physics and Applied Mathematics Department, Ural Federal University,Mira Street 19, 620002 Yekaterinburg (Russian Federation); Gavrilov, N.V. [Institute of Electrophysics, Russian Academy of Sciences, Ural Branch, 620990 Yekaterinburg (Russian Federation); Kurmaev, E.Z. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation); Zatsepin, A.F. [Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation); Cui, L. [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Shur, V. Ya.; Esin, A.A. [Institute of Natural Sciences, Ural Federal University, 51 Lenin Ave, 620000 Yekaterinburg (Russian Federation)

    2017-05-31

    Highlights: • Two modes of ZnO:Pb in the bulk and surface morphologies were established: the high- and low-interaction. • It was shown the ambiguity contribution of Pb 4f − Zn 3s and Pb 5d − O 2s states into final electronic structure. • The main type of defects is PbO-like with some PbO{sub 2}-like contributions. • An applied wurzite-like structural model well agrees with experimental data obtained for zincite. - Abstract: The electronic structures of zincite Pb-modulated bulk and thin-films were studied via X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) techniques. Both XPS data and DFT-calculations allowed the derivation of two different Pb-embedding scenarios into the ZnO-hosts. These included the high-interaction mode of Pb-impurity with initial zinc-oxygen host-lattice for the bulk morphology, accompanied with low Pb-metal losses; and the low-interaction mode for thin-films, where there was intake of Pb-impurities into the hollows of the surface. Despite dissimilar mechanisms of Pb-impurity accumulation and distribution in the bulk and thin-films zincite host-matrices, the strong Pb 4f — Zn 3s and Pb 5d — O 2s overlapped ambiguity contribution to the appropriate core-level structure and valence bands was established by XPS analysis and reproduced with the help of DFT-calculations. It was shown that the microscopic structure of the embedded lead-impurity played a crucial role in the Pb ion-beam stimulated synthesis of secondary lead-oxygen phases via large-area defect fabrication, and the difference among zincite and wurzite polymorphs played almost no role in this case.

  18. Realização do auto-exame das mamas por profissionais de enfermagem Realización del auto examen de los senos por profesionales de enfermería Breast self-examination by nursing professionals

    Directory of Open Access Journals (Sweden)

    Raimunda Magalhães da Silva

    2009-12-01

    Full Text Available Os tumores da mama, na maioria, são detectados pela mulher, portanto o autoexame das mamas (AEM ainda é uma estratégia eficaz. Objetivou-se analisar a realização do AEM por profissionais de enfermagem e fatores que dificultam a adesão dessa prática. Estudo descritivo, quantitativo, desenvolvido com 159 profissionais, sendo 40 enfermeiras, 48 auxiliares e 71 agentes de saúde, de 19 Unidades Básicas de Saúde de Fortaleza, Ceará. Os dados foram coletados com questionário autoaplicável e analisados com base na Teoria do Autocuidado. Das 159 profissionais, 86 (54% realizavam o AEM mensalmente. Das 73 que não realizavam, 60 (82% referiram como motivo o esquecimento, 38 (52% por não confiar na sua técnica/não sabiam a técnica correta, e 35 (48% por falta de atenção à saúde. Constatou-se que, apesar da maioria declarar fazer o AEM, as profissionais se sentiam inseguras e gostariam de aperfeiçoar esta prática.Los tumores del seno, en la mayoría, son detectados por la mujer, por lo tanto el auto examen de los senos (AES todavía es una estrategia eficaz. Se objetivó analizar la realización del AES por profesionales de enfermería y factores que dificultan la adhesión de esa práctica. Estudio descriptivo, cuantitativo, desarrollado con 159 profesionales, siendo 40 enfermeras, 48 auxiliares y 71 agentes de salud, de 19 Unidades Básicas de Salud de Fortaleza, Ceará. Los datos fueron recolectados con un cuestionario auto aplicable, y analizados con base en la Teoría del Auto Cuidado. De las 159 profesionales, 86 (54% realizaban el AES mensualmente. De las 73 que no lo realizaban, 60 (82% refirieron como motivo el olvido, 38 (52% por no confiar en su técnica/no sabían la técnica correcta, y 35 (48% por falta de atención a la salud. Se constató que, a pesar de que la mayoría declaró hacer el AES, las profesionales se sentían inseguras y les gustaría perfeccionar esta práctica.Most breast tumors are detected by women

  19. Thorium effect on the oxidation of uranium: Photoelectron spectroscopy (XPS/UPS) and cyclic voltammetry (CV) investigation on (U{sub 1−x}Th{sub x})O{sub 2} (x = 0 to 1) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Cakir, P., E-mail: pelincakir@outlook.com [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany); Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629, JB Delft (Netherlands); Eloirdi, R.; Huber, F. [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany); Konings, R.J.M. [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany); Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629, JB Delft (Netherlands); Gouder, T. [European Commission, Joint Research Centre, P.O. Box 2340, D-76125, Karlsruhe (Germany)

    2017-01-30

    Highlights: • XRD and XPS data of U{sub x}Th{sub 1-x}O{sub 2} films are in agreement with data obtained on bulk. • Oxygen affinity of thorium is much stronger than uranium. • Oxidation of uranium decreases as a function of thorium in the matrix. • XPS made pre and post CV shows thorium enrichment indicating a protective layer. • Higher initial uranium content is directly proportional to higher oxidation states. - Abstract: Thin films of U{sub 1−x}Th{sub x}O{sub 2} (x = 0 to 1) have been deposited via reactive DC sputter technique and characterized by X-ray/Ultra-violet Photoelectron Spectroscopy (XPS/UPS), X-ray Powder Diffractometer (XRD) and Cyclic Voltammetry (CV) in order to understand the effect of Thorium on the oxidation mechanism. During the deposition, the competition between uranium and thorium for oxidation showed that thorium has a much higher affinity for oxygen. Deposition conditions, time and temperature were also the subject of this study, to look at the homogeneity and the stability of the films. While core level and valence band spectra were not altered by the time of deposition, temperature was affecting the oxidation state of uranium and the valence band due to the mobility increase of oxygen through the film. X-ray diffraction patterns, core level spectra obtained for U{sub 1−x}Th{sub x}O{sub 2} versus the composition showed that lattice parameters follow the Vegard's law and together with the binding energies of U-4f and Th-4f are in good agreement with literature data obtained on bulk compounds. To study the effect of thorium on the oxidation of U{sub 1−x}Th{sub x}O{sub 2} films, we used CV experiments at neutral pH of a NaCl solution in contact with air. The results indicated that thorium has an effect on the uranium oxidation as demonstrated by the decrease of the current of the oxidation peak of uranium. XPS measurements made before and after the CV, showed a relative enrichment of thorium at the extent of uranium at

  20. Cefaleia por uso excessivo de medicamentos

    Directory of Open Access Journals (Sweden)

    Ariane Maria Fonseca MIRANDA

    2015-01-01

    Full Text Available Uma variante da cefaleia crônica diária, a cefaleia por uso excessivo de medicamentos é uma manifestação clínica de frequência ≥ 15 dias por mês, durante 3 meses. Possui um diagnóstico deficiente e um tratamento dividido em etapas, sendo a desintoxicação, a etapa de fundamental importância. Este artigo apresenta uma revisão sobre o tema, contribuindo para o esclarecimento das principais manifestações clínicas, principais teorias envolvendo sua fisiopatologia e a terapêutica farmacológica empregada. A metodologia utilizada foi uma revisão de publicações europeias e americanas, no período de 2001 a 2013, nos idiomas português, inglês e espanhol. Todos os medicamentos utilizados no tratamento sintomático das cefaleias são capazes de cronificar uma cefaleia preexistente, desde que sejam utilizados excessivamente, de forma regular e continuada. A suspensão de tais agentes terapêuticos resultará em melhoria na maioria dos pacientes, porém pode ser necessária a introdução de uma terapia de suporte de transição e/ou terapia profilática. Os tratamentos nao farmacológicos, quando associados ao farmacológico, ampliam a possibilidade de resultados satisfatórios, evitando recaídas.

  1. Vasculitis inducida por metimazol: Reporte de caso

    Directory of Open Access Journals (Sweden)

    Miguel Pinto

    2011-07-01

    Full Text Available Se reporta el caso de una paciente con enfermedad de Graves, que presentó vasculitis asociada al uso de metimazol. Mujer de 14 años, que acudió a consulta por presentar intolerancia al calor, tremor distal y palpitaciones. El examen físico mostró bocio difuso, y el perfil tiroideo, TSH suprimida y hormonas tiroideas elevadas. Los anticuerpos antiperoxidasa tiroidea fueron positivos. Se inició tratamiento con metimazol y beta bloqueadores. Después de 20 días, la paciente regresó por presentar malestar general, fiebre, poliartralgia, lesiones cutáneas maculopapulares y edema de miembros inferiores. Los anticuerpos antinucleares fueron negativos y los anticuerpos anticitoplasma de los neutrófilos (ANCA, positivos. Se suspendió el metimazol y se inició prednisona. Después de 10 días de tratamiento, las molestias desaparecieron y la paciente recibió I 131.Las vasculitis asociadas al uso de tionamidas son poco frecuentes, no dependen de la dosis y están asociadas a la presencia de anticuerpos tipo ANCA. Clásicamente, afectan a los vasos pequeños de la piel; sin embargo, también pueden afectar los riñones y pulmones. El cuadro clínico se caracteriza por artralgias y mialgias. En algunos casos puede ocurrir insuficiencia renal de grado variable. En la mayoría de casos, el cuadro remite con la suspensión de la droga; pero, en algunos se requiere el uso de glucocorticoides o inmunosupresores.(Rev Med Hered 2011;22:147-150.

  2. Diarrea recurrente por Cystoisopora belli en pacientes con infección por VIH con TARGA

    Directory of Open Access Journals (Sweden)

    Raúl Montalvo

    Full Text Available La Cystoisospora belli, antes denominada Isospora belli, es el agente etiológico de la cystoisosporiasis, una infección oportunista que afecta a pacientes inmunodeprimidos, caracterizada por diarrea crónica y pérdida ponderal. La incidencia de diarrea crónica por este agente, en pacientes infectados por el VIH, ha disminuido considerablemente. Ello gracias al advenimiento de la terapia antirretroviral de gran actividad (TARGA, con la que se ha logrado mejorar la respuesta inmunológica del paciente y disminuir su carga viral. Se presentan seis casos de cystoisosporiasis recurrente y refractaria en pacientes con infección por VIH, en quienes se diagnosticó cystoisosporiasis pese a que previamente se encontraban recibiendo profilaxis con trimetropin/sulfametoxazol (TMP/SMX. Cinco de ellos evolucionaron de manera tórpida y fallecieron, a pesar de una buena respuesta al TARGA (adecuado incremento de CD4 y disminución de la carga viral hasta rangos indetectables, y de tratamiento con TMP/SMX por vía oral y otros medicamentos de segunda línea.

  3. Bacteremias por bacilos gram-negativos

    Directory of Open Access Journals (Sweden)

    Adrelírio J. R. Gonçalves

    1969-01-01

    Full Text Available São apresentados 31 casos de bacteremia por gram-negativos, assunto que vem merecendo muita atenção dos pesquisadores nos últimos anos. Os organismos etiológicos mais importantes que apareceram em igualdade de freqüência foram Escherichia coli e Klebsiella-Aerobacter, sendo responsáveis por 58% do total das infecções, seguidos por Pseudomonas. A porta de entrada mais freqüente foi o trato urinário em 61,3% dos casos. A infecção foi mais comum no sexo masculino e a faixa etária de 50 a 60 anos predominou. O uso prévio de antibióticos foi um fator predisponente muito importante, seguido pelo uso de esteróides e citostáticos. As principais doenças predisponentes foram diabetes mellitus e neoplasias malignas. Os principais fatores precipitantes foram a manipulação do aparelho urinário, com infecção prévia ou desencadeada, cirurgia do aparelho digestivo, uronatia obstrutiva e obstrução biliar. As principais manifestações clínicas foram a presença de febre, calafrios e hipotensão arterial. A complicação mais freqüente foi o choque bacteriano que incidiu em 58% dos casos, aproximadamente três vêzes aquela relatada na literatura. As outras foram a insuficiência renal aguda, superinfecção e infecção pulmonar metastática. Considerações terapêuticas gerais e esquemas de antibióticos são propostos para estes casos. A mortalidade da bacteremia simples foi de 30,7% e quando associada ao choque elevou-se para 72,2% . As infecções por Pseudomonas foram 100% fatais.

  4. Intoxicación ocupacional por mercurio

    OpenAIRE

    Ramírez, Augusto V

    2013-01-01

    El mercurio, metal pesado ampliamente utilizado por el hombre, es muy tóxico; produce daño al sistema nervioso central, perturbaciones del comportamiento y lesiones renales. Se acumula en todos los seres vivos y no es esencial para ningún proceso biológico. La toxicidad del mercurio está directamente relacionada con su estado químico. El metilmercurio es la forma más dañina, con efectos neurotóxicos en adultos y en fetos de madres expuestas. El mercurio metálico no es menos tóxico. Las sales ...

  5. Intoxicación ocupacional por mercurio

    OpenAIRE

    Augusto V Ramírez

    2008-01-01

    El mercurio, metal pesado ampliamente utilizado por el hombre, es muy tóxico; produce daño al sistema nervioso central, perturbaciones del comportamiento y lesiones renales. Se acumula en todos los seres vivos y no es esencial para ningún proceso biológico. La toxicidad del mercurio está directamente relacionada con su estado químico. El metilmercurio es la forma más dañina, con efectos neurotóxicos en adultos y en fetos de madres expuestas. El mercurio metálico no es menos tóxico. Las sales ...

  6. Red universitaria por la permanencia estudiantil

    OpenAIRE

    Ramos Orlando, Barrera; Eva María, Osma Moreno

    2017-01-01

    La siguiente experiencia recoge el camino recorrido en la conformación de la Red Universitaria por la Permanencia Estudiantil, ya que ni en Bogotá, ni en Colombia, se venía trabajando de manera conjunta y organizada en torno a la permanencia estudiantil, aunque si existen eventos interinstitucionales, pero solo para mostrar los resultados de trabajos al interior de cada universidad o de investigaciones de deserción estudiantil. El objetivo de esta iniciativa es “consolidar una red de universi...

  7. Estudio del desgaste por deslizamiento en bronces

    OpenAIRE

    Carlos Holguín; John Coronado

    2007-01-01

    Se evaluaron tres bronces: SAE 67, nacional y americano usados típicamente como material de la chumacera en los molinos de caña de azúcar. Se realizaron pruebas desgaste por deslizamiento bajo la norma G77 usando bloques de bronce, anillos de acero SAE 1045 y aceite como lubricante. El tribómetro se calibró usando los anillos de acero SAE 4620 y se usó acero de herramienta SAE O1 para los bloques. Se realizaron metalografías, durezas y rugosidad de los materiales estudiados. El bronce naciona...

  8. Principo de micromanipulacion inmersa por hielo.

    OpenAIRE

    C. Lopez Walle, Beatriz; Gauthier, Michaël; Chaillet, Nicolas

    2007-01-01

    International audience; Uno de los mayores problemas en la manipulación y ensamble de micro-objetos cuyo tamaño está comprendido entre un micrómetro y un milímetro es el desarrollo de estrategias de prensión altamente fiables y precisas, particularmente durante la fase de liberación del micro-objeto [1], [2]. Además, cuando las dimensiones del objeto son inferiores a 100 µm, la fase de liberación está fuertemente perturbada por el ambiente [3], [4]. Un análisis comparativo en [5] muestra que ...

  9. El amor por la marca: Lovemark

    OpenAIRE

    Abigail Domínguez Orozco

    2011-01-01

    La marca se ha convertido en un estilo de vida, un tipo de status. Una lovemark es algo más que una marca, un sentimiento, aquello por lo que sus consumidores promueven y defienden. En este artículo se analizan diversos rasgos de personalidad que conforman a una lovemark. Se evalúan marcas de ropa y se llega a la conclusión que los rasgos asociados a la sofisticación son los más importantes en el mercado analizado

  10. Enfermedades de origen bacteriano transmitidas por vectores

    OpenAIRE

    Silva López, Laura

    2016-01-01

    Las enfermedades bacterianas transmitidas por vectores son un problema creciente en nuestra sociedad. En los últimos años se ha observado un aumento de la población tanto de garrapatas como de pulgas y mosquitos que, unido a la globalización y viajes internacionales, está llevando a la expansión de enfermedades a nuevas áreas geográficas. La dificultad de diagnóstico de estas enfermedades junto con la falta de recursos para tratarlas en países en desarrollo dan lugar a un elevado número de...

  11. TELECENTROS COMUNITARIOS MANIZALES VISTOS POR SUS USUARIOS

    Directory of Open Access Journals (Sweden)

    JUlio César Meza Ramírez

    2015-09-01

    Full Text Available El artículo presenta un ejercicio de evaluación de los Telecentros Comunitarios de la ciudad de Manizales (Caldas, Colombia, con el fin de identificar la percepción que sobre ellos tienen sus usuarios. Para ello se encuestan a 597 usuarios que han cursado alguna de las capacitaciones ofrecidas por Manizales Vive Digital, que reflejan la alta aceptación del programa y su efecto positivo sobre el proceso de inclusión digital en la ciudad.

  12. Tratamiento de la Enuresis por Biofeedback.

    OpenAIRE

    Leal López, Antonio

    2017-01-01

    Como ya hemos referido en anteriores líneas, a la clínica urológica nos llegan pacientes enuréticos que ya han sido tratados por los medios habituales sin obtener resultados. Estos enfermos nos eran remitidos para descartar la existencia de disfunciones vesicales neurógenas, mediante las técnicas urodinámicas. Los hallazgos obtenidos en estas exploraciones los comentábamos anteriormente, en el capítulo dedicado al diagnostic...

  13. Hipotiroidismo inducido por Amiodarona. Reporte de caso.

    OpenAIRE

    Salinas Arce, Jorge Luis; Instituto Nacional Cardiovascular (INCOR), EsSALUD. Lima. Servicio de Cardiología, Clínica El Golf. Lima.; Pinto Valdivia, Miguel; Servicio de Endocrinología, Hospital Nacional Cayetano Heredia. Lima, Perú. Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia. Lima.; Solórzano Altamirano, Paula; Servicio de Cardiología, Clínica El Golf. Lima.

    2012-01-01

    Se describe el caso de una mujer de 57 años de edad, con diagnóstico de síndrome de Wolf Parkinson White, en tratamiento con amiodarona 200 mg/día; que acudió por presentar palpitaciones, fatiga y aumento de sueño. Al examen físico no se encontró bocio, pero los reflejos osteotendinosos estaban prolongados. Los exámenes auxiliares mostraron TSH elevado, T4 libre disminuido y anticuerpos antiperoxidasa tiroidea negativos. Se suspendió la amiodarona y se inició levotiroxina. Después de dos mese...

  14. Refrigeración solar por eyector

    OpenAIRE

    Pizarro Romanillos, Raúl

    2014-01-01

    La finalidad de este trabajo es el estudio de un método de refrigeración que ayude a reducir el impacto medioambiental que producen otros sistemas de refrigeración más convencionales. Este método consiste en combinar la energía del Sol, que es renovable y gratuita, con un sistema de refrigeración por eyección que, a pesar de no tener alta eficiencia, tiene importantes ventajas como la de tener un bajo coste y una menor complejidad que otros sistemas. Para comenzar el estudio se hará un bre...

  15. Por uma arte no mundo da vida

    Directory of Open Access Journals (Sweden)

    Rachel Costa

    2016-12-01

    Full Text Available O artigo visa debater a análise colocada por Jacinto Lageira no texto “As razões do agir, contribuição a uma poética da ação”. O debate se estabelece no que concerne ao problema da autonomia da arte e suas consequências, tendo em vista a necessidade de pensar possibilidades contemporâneas para a experiência estética que pressuponham o mundo material. Isso é realizado a partir da teoria dos gestos do filósofo Vilém Flusser.

  16. Pênfigo vegetante induzido por uso de enalapril

    OpenAIRE

    Adriano,André Ricardo; Gomes Neto,Antonio; Hamester,Gustavo R; Nunes,Daniel H; Di Giunta,Gabriella

    2011-01-01

    Pênfigo Vegetante foi primeiramente descrito como uma variante do pênfigo vulgar, em 1876, por Neumann. Em 1889, Hallopeau descreveu um paciente com pústulas e placas vegetantes, e sugeriu ser uma variante do Pênfigo Vegetante de Neumann. Ambos os tipos de pênfigo vegetante são caracterizados pelo desenvolvimento de placas vegetantes, especialmente, em dobras (axila, inguinal, perianal). Os autores apresentam e discutem um caso de Pênfigo Vegetante com uma clínica incomum, com ausência de aco...

  17. Osteonecrosis de hueso maxilar inducida por bisfosfonatos

    OpenAIRE

    Vera Sempere, Francisco José

    2016-01-01

    Los bisfosfonatos son un grupo de fármacos, análogos de los pirofosfatos, utilizados en administración oral en el tratamiento de la osteoporosis, así como en formulaciones intravenosas para el tratamiento del dolor óseo y de la hipercalcemia ligada a la enfermedad tumoral metastasica (generalmente en el contexto de mieloma múltiple / cáncer de mama o próstata avanzados), actuando como un inhibidor de la reabsorción ósea, mediada por osteoclastos, así como de la apoptosis de los osteobl...

  18. Efeito sobre a morfologia do esmalte dental e análise físico-química de medicamentos utilizados por pacientes pediátricos com paralisia cerebral

    Directory of Open Access Journals (Sweden)

    Vanessa Feitosa ALVES

    Full Text Available Resumo Introdução Muitos medicamentos pediátricos líquidos são considerados fatores de risco para a estrutura dentária. Esse potencial pode aumentar quando ingeridos de forma crônica, como é o caso do tratamento de algumas condições, tal como a paralisia cerebral. Objetivo Avaliar o efeito sobre a morfologia do esmalte dental e as propriedades físico-químicas de medicamentos de uso contínuo indicados a pacientes infantis com Paralisia Cerebral. Material e método A amostra foi constituída por quatro medicamentos: Fenobarbital (M1, Carbamazepina (M2, Oxcarbazepina (M3 e Domperidona (M4, todos em suspensão oral. Analisaram-se o pH, o teor de Sólidos Solúveis Totais (SST e a viscosidade dos medicamentos. Todos os testes foram realizados em duplicata. Para análise em microscopia eletrônica de varredura (MEV, 15 blocos de esmalte bovino foram distribuídos aleatoriamente e imersos em oxcarbamazepina (n=5, carbamazepina (n=5 e saliva artificial (n=5. Os ciclos de imersão foram feitos por seis dias, durante cinco minutos, duas vezes ao dia, com intervalos de 12 horas, quando ficavam mantidos em saliva artificial. O grupo controle permaneceu em saliva artificial. Os dados foram analisados descritivamente. Resultado Em relação ao pH endógeno, os valores variaram de 2,82 (M3 a 9,60(M1. Para o SST, as médias de maior e menor valor foram, respectivamente, de 20,5% (M3 e 46% (M1. A viscosidade variou de 6,89 mm2/s (M1 a 58 mm2/s (M3. Em MEV, observaram-se alterações sugestivas de perda de estrutura no esmalte dental em oxcarbamazepina e carbamazepina, proveniente da ação dos medicamentos analisados. Conclusão Concluiu-se que os medicamentos líquidos pediátricos analisados, indicados a pacientes com paralisia cerebral, apresentam potencial cariogênico e erosivo, destacando-se a Oxcarbazepina.

  19. Nodulose por Metotrexato Methotrexate Induced Nodulosis

    Directory of Open Access Journals (Sweden)

    Fernanda Guidolin

    2005-08-01

    Full Text Available A nodulose por metotrexato (MTX é um dos efeitos colaterais pouco conhecidos do uso desse medicamento em doses baixas. Embora classicamente descrita em casos de artrite reumatóide, tem aparecido, também, em outras doenças reumáticas. Descreve-se aqui um caso de nodulose por MTX em uma paciente com artrite reumatóide soropositiva, que utilizava esse medicamento há um ano, com bom controle do processo articular. Segue-se uma breve revisão sobre o assunto.Methotrexate-induced nodulosis is a rare side effect of this drug when it is used in low doses. Although classically described in rheumatoid arthritis patients, it may also appear in other rheumatic disorders. We describe a seropositive rheumatoid arthritis patient who developed methotrexate-induced nodulosis after using this drug for a year, with good control of articular symptoms. This case presentation is followed by a brief revision on the subject.

  20. Investigando o Consumo de Lazer por Idosos

    Directory of Open Access Journals (Sweden)

    Marcelo de Rezende Pinto

    2015-06-01

    Full Text Available A partir da constatação de que ainda são incipientes os estudos que buscam investigar a perspectiva cultural do consumo, atrelada à percepção de que pouco se pesquisou sobre o consumo de lazer de consumidores da terceira idade, o artigo tem por objetivo geral apresentar resultados de uma pesquisa empírica cujo objetivo foi investigar como as experiências de consumo nas atividades de lazer por indivíduos da terceira idade interagem com o sistema cultural e simbólico envolvido no fluxo da vida social cotidiana. Para se atingir esses objetivos, adotou-se uma perspectiva interpretativa de investigação, a partir de uma abordagem etnográfica. Os resultados parecem indicar que os processos sociais, desde a construção de relacionamentos entre familiares, amigos e vizinhos até a construção de redes de convivência com integrantes dos clubes de terceira constituem-se os principais processos presentes nas atividades de lazer desses indivíduos.

  1. Hipotiroidismo inducido por Amiodarona: Reporte de caso

    Directory of Open Access Journals (Sweden)

    Jorge Luis Salinas Arce

    2012-03-01

    Full Text Available Se describe el caso de una mujer de 57 años de edad, con diagnóstico de síndrome de Wolf Parkinson White, en tratamiento con amiodarona 200 mg/día; que acudió por presentar palpitaciones, fatiga y aumento de sueño. Al examen físico no se encontró bocio, pero los reflejos osteotendinosos estaban prolongados. Los exámenes auxiliares mostraron TSH elevado, T4 libre disminuido y anticuerpos antiperoxidasa tiroidea negativos. Se suspendió la amiodarona y se inició levotiroxina. Después de dos meses; los niveles de TSH y T4 libre eran normales y la paciente no presentaba molestias. La amiodarona está asociada a diversos efectos adversos que pueden limitar su uso. Entre estos efectos adversos, se describe el hipotiroidismo inducido, que se caracteriza por TSH elevado, T4 libre disminuido y síntomas inespecíficos como fatiga, intolerancia al frío y piel seca. El tratamiento de elección es la levotiroxina.

  2. Estenosis mitral por mixoma auricular izquierdo

    Directory of Open Access Journals (Sweden)

    Orlando D. Navarro

    2016-07-01

    Full Text Available Los tumores cardiacos representan el 0.2% y pueden ser primarios o metastásicos (secundarios, siendo estos últimos 20 a 40 veces más comunes que los primarios. De los tumores primarios, el 75% son benignos y aproximadamente el 50-85% de estos corresponden a mixomas, con una incidencia de 0.5-1 por 106 individuos por año. Se presenta el caso de un paciente de 56 años de edad, sin factores de riesgo cardiovascular ni antecedentes patológicos, con un mixoma auricular izquierdo de 4,6 × 4,5 cm, que prolapsaba hacia la válvula mitral en diástole provocando obstrucción intermitente de la misma y estenosis mitral severa. El diagnóstico se realizó mediante una ecocardiografía transtorácica, sin requerir de otras pruebas diagnósticas. Se realizó resección quirúrgica, lográndose la resección completa del tumor. La evolución posterior del paciente fue satisfactoria, siendo egresado a los 11 días de la intervención.

  3. Meningitis neonatal por Neisseria meningitidis serogrupo B

    Directory of Open Access Journals (Sweden)

    Manuel Díaz Álvarez

    Full Text Available La meningitis meningocóccica es una infección poco frecuente en el período neonatal internacionalmente, y solo hay una publicación previa en la literatura médica cubana hace 25 años atrás, de recién nacidos con meningitis bacteriana causada por Neisseria meningitidis. Se presenta el caso de un recién nacido febril, con manifestaciones de toxicidad, fontanela abombada, y cuando se realizó punción lumbar, se encontró pleocitosis del líquido cefalorraquídeo y se aisló N. meningitidis serogrupo B, por lo que se diagnostica meningitis meningocóccica neonatal. Tuvo evolución favorable. Se describen algunas características de la infección meningocócica, y se destaca el diagnóstico y tratamiento recomendado para este tipo de infección, así como se hace referencia a reportes de casos publicados en la literatura internacional.

  4. Por um mundo de palavras vivas

    Directory of Open Access Journals (Sweden)

    Fernanda Cupolillo Miana de Faria

    2011-01-01

    Full Text Available

    O presente artigo pretende fazer uma reflexão, a partir de Gramsci e de Sartre, sobre como as práticas do intelectual e do jornalista, formados em um mesmo locus social, como “técnicos do saber prático”, distanciam-se em virtude dos diferentes compromissos assumidos socialmente. O artigo pretende expor, portanto, alguns dos motivos, a partir da prática do jornalista, que o levam a se afastar da noção de intelectual, embora, muitas vezes, ele reivindique esse status. Argumenta-se sobre como a incorporação da retórica da neutralidade pelos jornalistas, derivada do racionalismo de que a classe burguesa se tornou representante, constituiu um dos braços para a construção dos pressupostos jornalísticos da imparcialidade e da objetividade. Por fim, argumenta-se, a partir das revistas semanais de informação Época, Veja e Istoé, sobretudo nas reportagens de comportamento, sobre como essa retórica instaura uma falsa arena de discussão pluralista nesses semanários sustentada por uma visão naturalizadora das relações humanas, valores, práticas culturais e do próprio ser humano.   

  5. Lucro por ação

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    Gabriel Moreira Campos

    2001-08-01

    Full Text Available Este trabalho tem por objetivo demonstrar os principais conceitos acerca do Lucro por Ação (Earnings per Share, o qual se apresenta como um quociente de grande utilidade nas entidades. Serão demonstrados aspectos sobre o assunto presentes no Brasil, bem como as normas aplicáveis nos Estados Unidos, emanadas do Financial Accounting Standards Board (FASB, e as normas internacionais, emanadas do International Accounting Standards Committee (IASC. De forma a possibilitar uma visualização mais completa dos conceitos envolvidos, serão desenvolvidos exemplos de sua aplicação. O Lucro (Resultado por Ação pode ser calculado em sua forma básica e em sua forma diluída. Na forma básica, não são considerados os efeitos dos instrumentos potencialmente dilutivos, ao passo que, no cálculo do Lucro (Resultado por Ação Diluído, são. Como instrumentos financeiros potencialmente dilutivos temos as ações preferenciais conversíveis, as debêntures conversíveis e os bônus de subscrição, que podem ser convertidos em ações ordinárias, caracterizando, assim, o próprio potencial dilutivo desses instrumentos. Dessa forma, o trabalho em questão foi dividido em três partes principais, sendo que nas duas últimas constam os referidos exemplos de cálculo do Lucro por Ação em sua forma básica e em sua forma diluída: • aspectos observados no Brasil; • normas emanadas do FASB; • normas emanadas do IASC.The objective of this paper is to demonstrate the principal concepts about Earnings per Share, which is presented as a quotient of great usefulness for the companies. The subject is presented in three parts: in the first part, we will demonstrate relevant aspects that are present in Brazil. In the second part, the applicable standards in the United States will be discussed, which are issued by the Financial Accounting Standards Board (FASB. In the third part, the international standards are dealt with, which are issued by the

  6. X-ray photoelectron (XPS) and Diffuse Reflectance Infra Fourier Transformation (DRIFT) study of Ba 0.5Sr 0.5Co xFe 1- xO 3 -δ (BSCF: x=0-0.8) ceramics

    Science.gov (United States)

    Jung, Jae-Il; Edwards, Doreen D.

    2011-08-01

    The X-ray photoelectron spectra (XPS) of sintered BSCF ceramics (Ba 0.5Sr 0.5Co xFe 1- xO 3- δ,0≤ x≤0.8) were measured at room temperature (RT). Peak areas of Fe 2 p1 , Fe 2 p3 , Fe 3 p and Co 3 p increased systematically with increasing cobalt concentration, while their binding energies (BEs) remained the same (723.3, 710.0, 55.0 and 60.9 eV, respectively). However, the BEs of lattice oxygen in O 1 s (528.1 eV) and Ba 4 d for the BaO bond (87.9V and 90.2 eV) increased with increasing cobalt concentration. The shoulder peak of Ba 3 d/Co 2 p increased from 778.0 to 778.7 eV, which implies that this peak can be attributed to another Ba XPS peak (described as Ba 2nd in this study) due to the overlapping area between barium cations and oxygen anions. The overall peak areas of Ba 4 d increased up to x=0.4, and then decreased, which coincides with the behavior of the Diffuse Reflectance Infrared Fourier Transform (DRIFT) bands representing adsorbed CO 32- ( νCO 32-) and structurally bonded CO 32- ( ν2, ν3) (800-1200 and 862/1433 cm -1, respectively).

  7. XPS-UPS, ISS characterization studies and the effect of Pt and K addition on the catalytic properties of MoO{sub 2-x}(OH){sub y} deposited on TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kandari, H. [Public Authority of Applied Education and Training (Kuwait); Mohamed, A.M.; Al-Kharafi, F. [Kuwait University, Department of Chemistry, P.O. Box 5969, Safat 13060 (Kuwait); Katrib, A., E-mail: ali.katrib@ku.edu.kw [Kuwait University, Department of Chemistry, P.O. Box 5969, Safat 13060 (Kuwait)

    2011-11-15

    Highlights: {yields} Surface electronic structure-catalytic activity correlation is presented in this research work. {yields} In situ characterization by XPS-UPS and ISS techniques were employed at the same experimental conditions applied for catalytic reactions. {yields} Catalytic reactions of Mo deposited on titanium oxide for the isomerization and hydrogenation reactions using 1-hexene and n-hexane were studied. {yields} The bifunctional properties of the molybdenum dioxide phase were modified by the addition of potassium. - Abstract: Characterization by XPS-UPS, ISS surface techniques of MoO{sub 3}/TiO{sub 2} catalysts before and after addition of Pt (PtMo) 2.5% by weight of MoO{sub 3} and potassium (KMo) enabled to identify different chemical species present on the outermost surface layer at different reduction temperatures. Catalytic activities of these systems using 1-hexene and n-hexane reactants were studied. Correlation between catalytic activity and surface electronic structure enabled us to identify the chemical species, active site(s), responsible for specific catalytic reaction(s).

  8. XPS-UPS, ISS characterization studies and the effect of Pt and K addition on the catalytic properties of MoO2-x(OH)y deposited on TiO2

    International Nuclear Information System (INIS)

    Al-Kandari, H.; Mohamed, A.M.; Al-Kharafi, F.; Katrib, A.

    2011-01-01

    Highlights: → Surface electronic structure-catalytic activity correlation is presented in this research work. → In situ characterization by XPS-UPS and ISS techniques were employed at the same experimental conditions applied for catalytic reactions. → Catalytic reactions of Mo deposited on titanium oxide for the isomerization and hydrogenation reactions using 1-hexene and n-hexane were studied. → The bifunctional properties of the molybdenum dioxide phase were modified by the addition of potassium. - Abstract: Characterization by XPS-UPS, ISS surface techniques of MoO 3 /TiO 2 catalysts before and after addition of Pt (PtMo) 2.5% by weight of MoO 3 and potassium (KMo) enabled to identify different chemical species present on the outermost surface layer at different reduction temperatures. Catalytic activities of these systems using 1-hexene and n-hexane reactants were studied. Correlation between catalytic activity and surface electronic structure enabled us to identify the chemical species, active site(s), responsible for specific catalytic reaction(s).

  9. Combined atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and quartz crystal microbalance (QCM) studies of glucose oxidase (GOx) immobilised onto self-assembled monolayer on the gold film

    International Nuclear Information System (INIS)

    Losic, D.; Shapter, J.; Gooding, J.; Erokin, P.; Short, K.

    1999-01-01

    In fabrication of biosensors, self-assembled monolayers (SAM) are an attractive method of immobilising enzymes at electrode surface since it allows precise control over the amount and spatial distribution of the immobilized enzyme. The covalent attachment of glucose oxidase (GOx) to a carboxylic terminated SAM chemisorbed onto gold films was achieved via carbodiimide activation of the carboxylic acids to a reactive intermediate susceptible to nucleophilic attack by amines on free lysine chains of the enzyme. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and quartz crystal microbalance (QCM) measurements were used for characterisation of GOx modified gold surfaces. Tapping mode AFM studies have revealed that GOx molecules form slightly disordered arrays of pentagonal or hexagonal clusters. Observed features of immobilised GOx are distributed as a submonolayer on the SAM surface which has allowed visualisation of native and unfolded enzyme structure. The presence of the SAM and enzyme on the gold surface was detected by XPS spectroscopy. Spectra show typical peaks for the C 1s, O 1s and N 1s regions. A kinetic study of the adsorption of GOx onto activated SAM using in-situ QCM allowed determination the amount of immobilised GOx on the layer and consequently the optimal immobilisation conditions. Performance parameters of the biosensor such as sensitivity to glucose concentration as a function of enzyme loading were evaluated amperometrically using the redox mediator p-benzoquinone

  10. Excreção de amônia por tambaqui (Colossoma macropomum de acordo com variações na temperatura da água e massa do peixe

    Directory of Open Access Journals (Sweden)

    Ismiño-Orbe Rosa Angélica

    2003-01-01

    Full Text Available A amônia, produto de excreção dos peixes, é tóxica para organismos aquáticos. O objetivo deste trabalho foi quantificar taxas de excreção diária de amônia em tambaqui (Colossoma macropomum, principal espécie criada na Amazônia, que podem variar de acordo com a temperatura da água e a massa dos peixes. As taxas de excreção foram determinadas a cada 2 horas por um período de 24 horas e os resultados analisados por uma regressão linear múltipla. O tambaqui apresentou de dois a cinco picos de atividade de excreção durante 24 horas, caracterizados por rápidos aumentos de até dez vezes na taxa horária de excreção. O modelo desenvolvido pela regressão linear múltipla explicou 95,2% da taxa diária de excreção de amônia, que aumentou com a massa do peixe, mas diminuiu com o aumento da temperatura da água.

  11. Toxicidad por óxido de etileno

    Directory of Open Access Journals (Sweden)

    Téllez M. Jairo A.

    1993-08-01

    Full Text Available

    El óxido de etileno, es un compuesto epóxido gaseoso, ampliamente utilizado en nuestro medio como agente esterilizante y de desinfección en instituciones hospitalarias. Los estudios realizados en varios países han demostrado efectos sobre la salud humana, caracterizados por  hipersensibilidad dérmica, irritación del tracto respiratorio, irritación ocular, excitación del S.N.C. y se asocia con presencia de abortos expontáneos, aberraciones cromosómicas e irritación crónica de laringe y tráquea en personal expuesto ocupacionalmente.

  12. La Violencia Latinoamericana vista por los Economistas

    Directory of Open Access Journals (Sweden)

    Salama Pierre

    2003-08-01

    Full Text Available

    Salama, Pierre. "La Violencia Lationoamericana vista por los Economistas", Cuadernos de Economía, V. XXII, n. 38, Bogotá, 2003 páginas 179-198.

    Este articulo sintetiza los estudios económicos publicados recientemente sobre la violencia en América Latina y analiza las causas suceptibles a acrecentarla: pobreza, desigualdad de los ingresos en nivel y variación, impunidad, diferencia entre la probabilidad de ser arrestado y la severidad de la pena impuesta, y narcotrafico. Sin embargo, la explicación de la violencia no se limitará a los factores económicos, puesto que el autor privilegia un enfoque inspirado en la antropología y la sociología.

  13. Conservación por calor

    OpenAIRE

    Cobos García, Angel; Díaz Rubio, Olga

    2011-01-01

    Grao en Nutrición Humana e Dietética Esta unidade didáctica denominada Conservación por calor forma parte da materia «Tecnoloxía do procesado de alimentos» que se impartirá no primeiro semestre do 2º curso do Grao en Nutrición Humana e Dietética. A materia estrutúrase en diferentes unidades didácticas, tratando cada unha delas as diferentes tecnoloxías de procesado dos alimentos, tanto de conservación coma de transformación. A presente unidade didáctica aborda a conservación dos alimentos ...

  14. Infeções alimentares por Campylobacter

    OpenAIRE

    Neto, Carlota Duarte Castro

    2017-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz Após o isolamento bem-sucedido em fezes na década de setenta do século passado (1972), Campylobacter tornou-se rapidamente a espécie bacteriana mais comumente associada a doenças diarreicas em todo o mundo. A infeção por Campylobacter provoca um espectro de doenças, incluindo enterite aguda, infeções extra-gastrointestinais e complicações pós-infeciosas. A doença gastrointestinal autolimita...

  15. Síndrome cerebeloso por amiodarona

    Directory of Open Access Journals (Sweden)

    Neuda S. Garretto

    1994-12-01

    Full Text Available La amiodarona (AMD es una droga antiarritmica cuyos efectos adversos pueden comprometer el sistema nervioso central y periferico. La aparición de un síndrome cerebeloso es infrecuente. Se presenta un paciente masculino de 56 anos de edad que desarolla un síndrome pancerebeloso de 4 meses de evolución, que revierte luego de la suspension de la AMD. El cuadro reaparece meses mas tarde luego de un periodo de automedicacion con la droga. Los mecanismos tóxicos por los cuales la AMD afecta al cerebelo permanecen inciertos. Esta droga de amplia difusión en nuestro medio, como otros antiarritmicos, posee efectos sobre el sistema nervioso que deben ser tenidos en cuenta a fin de poder detectarlos precozmente.

  16. Herida por arma de fuego Gunshot wounds

    OpenAIRE

    A. Sibón Olano; P. Martínez-García; E. Santiago Romero

    2003-01-01

    En el examen de las heridas por arma de fuego, hay que prestar especial interés al orifico de entrada. Un examen minucioso del mismo, nos permitirá conocer la distancia a la que se ha efectuado el disparo; así mismo, nos orientará sobe la trayectoria y etiología médico-legal. El tipo de arma puede modificar en alguna medida el orificio de entrada en los disparos a cañón tocante; como ocurre en las armas de dos cañones, en las que tiene situada su mira en la boca del cañón, o en las que están ...

  17. fluidizado por proceso autotérmico

    Directory of Open Access Journals (Sweden)

    ZULAMITA ZAPATA BENABITHE

    2005-01-01

    Full Text Available El presente trabajo se basa en el estudio de la producción de carbón activado a partir de carbón mineral subbituminoso en un reactor de lecho fluidizado por proceso autotérmico. El carbón utilizado provino de la región de Amagá (Antioquia - Colombia y fue activado en dos reactores de lecho fluidizado de diferente diámetro interno, 10 cm y 22 cm. Los valores del área superficial específica y el volumen de poro de las muestras activadas fueron determinados a partir de las isotermas de N2 y CO2. Los resultados experimentales mostraron que los valores de áreas superficiales BET y DR y del Índice de Yodo se encontraron alrededor de 460 m2/g (SBET, 490 m2/g (SDR y 460 mg I2/g carbón.

  18. Pneumonia por "Pneumocystis carinii": forma tumoral

    Directory of Open Access Journals (Sweden)

    BARRA LUIZ ALBERTO COSTA

    2000-01-01

    Full Text Available A pneumocistose é uma infecção oportunística freqüente em imunodeprimidos, principalmente naqueles com a síndrome da imunodeficiência adquirida (AIDS. Relata-se o caso de um paciente com quadro insidioso de febre, tosse e emagrecimento. Na radiografia de tórax observou-se imagem tumoral em seio costofrênico direito. Iniciou-se uso de prova terapêutica para tuberculose com rifampicina, isoniazida e pirazinamida (esquema I, sem resolução. Posteriormente, foi realizada biópsia pulmonar "a céu aberto" e o estudo histopatológico revelou pneumonia por Pneumocystis carinii. Houve melhora clínica e radiológica após o início do tratamento específico.

  19. Cana-de-açúcar com irrigação por gotejamento em dois espaçamentos entrelinhas de plantio

    Directory of Open Access Journals (Sweden)

    Ricardo A. Ferreira Junior

    2014-08-01

    Full Text Available O manejo de irrigação por gotejamento e a colheita mecanizada na cultura da cana-de-açúcar estão sugerindo espaçamento entrelinhas de plantio do tipo combinado. Neste contexto, o objetivo do estudo foi avaliar o crescimento da variedade RB98710 irrigada por gotejamento em dois tipos de espaçamentos entrelinhas de plantio; para isto foram realizados dois plantios em agosto de 2011, sendo um com espaçamento entrelinhas de plantio único (1,0 m e outro combinado (0,6 e 1,4 m. Os dados analisados foram variáveis de crescimento (índice de área foliar, altura do dossel, comprimento dos colmos e plantas por metro quadrado, variáveis de produção e elementos meteorológicos. O valor do fator de forma para a área foliar foi igual a 0,65; em ambos os espaçamentos entrelinhas de plantio as variáveis de crescimento foram relacionadas com os graus-dia acumulados e tiveram equações ajustadas com aplicações satisfatórias. As variáveis de crescimento avaliadas não diferiram entre os espaçamentos de plantio utilizados. As produtividades de colmos frescos (100,9 t ha-1 e de açúcar (17,8 t ha-1 da cana-de-açúcar irrigada cultivada em Rio Largo, Alagoas, não foram influenciadas pelo uso dos diferentes tipos de espaçamentos entrelinhas de plantio.

  20. Forame Mentual: verificação da localização por meio de radiografia panorâmica

    Directory of Open Access Journals (Sweden)

    Ingrid Macedo de Oliveira

    2017-05-01

    Full Text Available A topografia do forame mentual é de grande importância na clínica odontológica, porque proporciona a realização de procedimentos seguros na mandíbula; no entanto, sua localização e características podem variar entre as populações. O objetivo do presente estudo foi descrever a topografia e as variações anatômicas do forame mental por meio de radiografias panorâmicas. Sendo um estudo retrospectivo transversal, feito por examinador previamente calibrado, foram analisados os antímeros direito e esquerdo de 100 radiografias panorâmicas, totalizando 200 forames. O forame foi classificado quanto à posição, em relação aos dentes inferiores, e quanto à altura, em relação à base da mandíbula. A análise das radiografias foi realizada sob negatoscópio e com auxílio de paquímetro digital. A estatística foi do tipo descritiva. Quanto à posição dos dentes, observou-se que o forame classe III (62% foi o de maior prevalência, seguido pelos de classe IV (23,5%, classe V (10,5%, classe VI (2% e classes I (1% e II (1%. As maiores alturas encontradas foram de 13mm e 14mm para os lados esquerdo e direito respectivamente. Houve variações na localização do forame mental, com maior prevalência do forame situado entre o primeiro e o segundo pré-molar. Porém houve proximidade entre as dimensões e a localização do forame mental nos dois lados de um mesmo exame radiográfico.