Analysis of XPS spectra of Fe 2+ and Fe 3+ ions in oxide materials

NASA Astrophysics Data System (ADS)

Yamashita, Toru; Hayes, Peter

2008-02-01

Samples of the iron oxides Fe 0.94O, Fe 3O 4, Fe 2O 3, and Fe 2SiO 4 were prepared by high temperature equilibration in controlled gas atmospheres. The samples were fractured in vacuum and high resolution XPS spectra of the fractured surfaces were measured. The peak positions and peak shape parameters of Fe 3p for Fe 2+ and Fe 3+ were derived from the Fe 3p XPS spectra of the standard samples of 2FeO·SiO 2 and Fe 2O 3, respectively. Using these parameters, the Fe 3p peaks of Fe 3O 4 and Fe 1- yO are analysed. The results indicate that high resolution XPS techniques can be used to determine the Fe 2+/Fe 3+ ratios in metal oxides. The technique has the potential for application to other transition metal oxide systems.

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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.

Morphological and XPS study of ball milled Fe1-xAlx (0.3≤x≤0.6) alloys

NASA Astrophysics Data System (ADS)

Rajan, Sandeep; Kumar, Anil; Vyas, Anupam; Brajpuriya, Ranjeet

2018-05-01

The paper presents mechanical and XPS study of ball milled Fe1-xAlx (0.3≤x≤0.6) alloys. The author prepared the solid solution of Fe(Al) with different composition of Al by using mechanical alloying (MA) technique. The MA process induces a progressive dissolution of Al into Fe, resulted in the formation of an extended Fe(Al) solid solution with the bcc structure after 5 hr of milling. The SEM Images shows that the initial shape of particles disappeared completely, and their structure became a mixture of small and large angular-shaped crystallites with different sizes. The TEM micrograph also confirms the reduction in crystallite size and alloy formation. XPS study shows the shift in the binding energy position of both Fe and Al Peaks provide strong evidence of Fe(Al) phase formation after milling.

Study of fission-product segregation in used CANDU fuel by X-ray photoelectron spectroscopy (XPS) II

NASA Astrophysics Data System (ADS)

Hocking, William H.; Duclos, A. Michael; Johnson, Lawrence H.

1994-03-01

A thorough investigation of the grain-boundary chemistry of used CANDU fuel from one intact element has been conducted by X-ray photoelectron spectroscopy (XPS). Selected findings from more extensive XPS measurements on other used CANDU fuels exposed to storage conditions are included for comparison. Cesium, rubidium, tellurium and barium have been commonly observed, often reaching high degrees of surface enrichment, although their relative abundances can vary widely with a complex dependence on the fuel irradiation history. Lower concentrations of cadmium, molybdenum, strontium and iodine have also been occasionally detected. Except for iodine, chemical-shift data are indicative of oxidized species, possibly uranates. Segregation at monolayer-level coverages has been demonstrated by sequential XPS analysis and argon-ion sputtering. Calculations based on an idealized thin-film model are consistent with the depth profiles. The interpretation of these results is discussed in the context of previous studies, especially on LWR fuels.

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

NASA Technical Reports Server (NTRS)

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.

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

PubMed

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.

Applications of XPS in the characterization of Battery materials

DOE PAGES

Shutthanandan, Vaithiyalingam; Nandasiri, Manjula; Zheng, Jianming; ...

2018-05-26

In this study, technological development requires reliable power sources where energy storage devices are emerging as a critical component. Wide range of energy storage devices, Redox-flow batteries (RFB), Lithium ion based batteries (LIB), and Lithium-sulfur (LSB) batteries are being developed for various applications ranging from grid-scale level storage to mobile electronics. Material complexities associated with these energy storage devices with unique electrochemistry are formidable challenge which needs to be address for transformative progress in this field. X-ray photoelectron spectroscopy (XPS) - a powerful surface analysis tool - has been widely used to study these energy storage materials because of itsmore » ability to identify, quantify and image the chemical distribution of redox active species. However, accessing the deeply buried solid-electrolyte interfaces (which dictates the performance of energy storage devices) has been a challenge in XPS usage. Herein we report our recent efforts to utilize the XPS to gain deep insight about these interfaces under realistic conditions with varying electrochemistry involving RFB, LIB and LSB.« less

Applications of XPS in the characterization of Battery materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shutthanandan, Vaithiyalingam; Nandasiri, Manjula; Zheng, Jianming

In this study, technological development requires reliable power sources where energy storage devices are emerging as a critical component. Wide range of energy storage devices, Redox-flow batteries (RFB), Lithium ion based batteries (LIB), and Lithium-sulfur (LSB) batteries are being developed for various applications ranging from grid-scale level storage to mobile electronics. Material complexities associated with these energy storage devices with unique electrochemistry are formidable challenge which needs to be address for transformative progress in this field. X-ray photoelectron spectroscopy (XPS) - a powerful surface analysis tool - has been widely used to study these energy storage materials because of itsmore » ability to identify, quantify and image the chemical distribution of redox active species. However, accessing the deeply buried solid-electrolyte interfaces (which dictates the performance of energy storage devices) has been a challenge in XPS usage. Herein we report our recent efforts to utilize the XPS to gain deep insight about these interfaces under realistic conditions with varying electrochemistry involving RFB, LIB and LSB.« less

Cohort study comparing prostate photovaporisation with XPS 180W and HPS 120W laser.

PubMed

López, B; Capitán, C; Hernández, V; de la Peña, E; Jiménez-Valladolid, I; Guijarro, A; Pérez-Fernández, E; Llorente, C

2016-01-01

Prostate photovaporisation with Greenlight laser for the surgical treatment of benign prostate hyperplasia has rapidly evolve to the new XPS 180W. We have previously demonstrated the safety and efficacy of the HPS 120W. The aim of this study was to assess the functional and safety results, with a year of follow-up, of photovaporisation using the XPS 180W laser compared with its predecessor. A cohort study was conducted with a series of 191 consecutive patients who underwent photovaporisation between 1/2008 and 5/2013. The inclusion criteria were an international prostate symptom score (IPSS) >15 after medical failure, a prostate volume <80 cm(3) and a maximum flow <15 mL/s. We assessed preoperative and intraoperative variables (energy used, laser time and total surgical time), complications, catheter hours, length of stay and functional results (maximum flow, IPSS, prostate-specific antigen and prostate volume) at 3, 6 and 12 months. We analysed the homogeneity in preoperative characteristics of the 2 groups through univariate analysis techniques. The postoperative functional results were assessed through an analysis of variance of repeated measures with mixed models. A total of 109 (57.1%) procedures were performed using HPS 120W, and 82 (42.9%) were performed using XPS. There were no differences between the preoperative characteristics. We observed significant differences both in the surgical time and effective laser time in favour of the XPS system. This advantage was 11% (48 ± 15.7 vs. 53.8 ± 16.2, p<.05) and 9% (32.8 ± 11.7 vs. 36 ± 11.6, p<.05), respectively. There were no statistically significant differences in the rest of the analysed parameters. The technical improvements in the XPS 180W system help reduce surgical time, maintaining the safety and efficacy profile offered by the HPS 120W system, with completely superimposable results at 1 year of follow-up. Copyright © 2015 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Eu(III) sorption to TiO2 (anatase and rutile): batch, XPS, and EXAFS studies.

PubMed

Tan, Xiaoli; Fan, Qiaohui; Wang, Xiangke; Grambow, Bernd

2009-05-01

The sorption of Eu(III) on anatase and rutile was studied as a function of ionic strength, humic acid (HA, 7.5 mg/L), and electrolyte anions over a large range of pH (2-12). The presence of HA significantly affected Eu(III) sorption to anatase and rutile. The sorption of Eu(III) on anatase and rutile was independent of ionic strength. Results of an X-ray photoelectron spectroscopy (XPS) analysis showed that Eu(III) was chemically present within the near-surface of TiO2 due to the formation of triple bond SOEu and triple bond SOHAEu complexes. An extended X-ray absorption fine structure (EXAFS) technique was applied to characterize the local structural environment of the adsorbed Eu(III), and the results indicated that Eu(III) was bound to about seven or eight O atoms at a distance of about 2.40 A. The functional groups of surface-bound HA were expected to be involved in the sorption process. The measured Eu-Ti distance confirmed the formation of inner-sphere sorption complexes on a TiO2 surface.

Transcription analysis of pilS and xpsEL genes from Xylella fastidiosa.

PubMed

Coltri, Patricia P; Rosato, Yoko B

2005-04-01

Xylella fastidiosa is a xylem-limited phytopathogen responsible for diseases in several plants such as citrus and coffee. Analysis of the bacterial genome revealed some putative pathogenicity-related genes that could help to elucidate the molecular mechanisms of plant-pathogen interactions. In the present work, the transcription of three genes of the bacterium, grown in defined and rich media and also in media containing host plant extracts (sweet orange, 'ponkan' and coffee) was analyzed by RT-PCR. The pilS gene, which encodes a sensor histidine kinase responsible for the biosynthesis of fimbriae, was transcribed when the bacterium was grown in more complex media such as PW and in medium containing plant extracts. The xps genes (xpsL and xpsE) which are related to the type II secretion system were also detected when the bacterium was grown in rich media and media with 'ponkan' and coffee extracts. It was thus observed that pilS and xpsEL genes of X. fastidiosa can be modulated by environmental factors and their expression is dependent on the nutritional status of the growth medium.

Toward a better determination of dairy powders surface composition through XPS matrices development.

PubMed

Nikolova, Y; Petit, J; Sanders, C; Gianfrancesco, A; Scher, J; Gaiani, C

2015-01-01

The surface composition of dairy powders prepared by mixing various amounts of micellar casein (MC), whey proteins isolate (WPI), lactose, and anhydrous milk fat (AMF) was investigated by XPS measurements. The use of matrices are generally accepted to transform surface atomic composition (i.e., C, O, N contents) into surface component composition (i.e., lactose, proteins, lipids). These atomic-based matrices were revisited and two new matrices based on the surface bond composition were developed. Surface compositions obtained from atomic and bond-based matrices were compared. A successful matrix allowing good correlations between XPS predicted and theoretical surface composition for powders free from fat was identified. Nevertheless, samples containing milk fat were found to present a possible segregation of components owing to the AMF overrepresentation on the surface. Supplementary analyses (FTIR, SEM) were carried out in order to investigate the homogeneity of the mixtures. Copyright © 2014 Elsevier B.V. All rights reserved.

Arsenopyrite and pyrite bioleaching: evidence from XPS, XRD and ICP techniques.

PubMed

Fantauzzi, Marzia; Licheri, Cristina; Atzei, Davide; Loi, Giovanni; Elsener, Bernhard; Rossi, Giovanni; Rossi, Antonella

2011-10-01

In this work, a multi-technical bulk and surface analytical approach was used to investigate the bioleaching of a pyrite and arsenopyrite flotation concentrate with a mixed microflora mainly consisting of Acidithiobacillus ferrooxidans. X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and X-ray-induced Auger electron spectroscopy mineral surfaces investigations, along with inductively coupled plasma-atomic emission spectroscopy and carbon, hydrogen, nitrogen and sulphur determination (CHNS) analyses, were carried out prior and after bioleaching. The flotation concentrate was a mixture of pyrite (FeS(2)) and arsenopyrite (FeAsS); after bioleaching, 95% of the initial content of pyrite and 85% of arsenopyrite were dissolved. The chemical state of the main elements (Fe, As and S) at the surface of the bioreactor feed particles and of the residue after bioleaching was investigated by X-ray photoelectron and X-ray excited Auger electron spectroscopy. After bioleaching, no signals of iron, arsenic and sulphur originating from pyrite and arsenopyrite were detected, confirming a strong oxidation and the dissolution of the particles. On the surfaces of the mineral residue particles, elemental sulphur as reaction intermediate of the leaching process and precipitated secondary phases (Fe-OOH and jarosite), together with adsorbed arsenates, was detected. Evidence of microbial cells adhesion at mineral surfaces was also produced: carbon and nitrogen were revealed by CHNS, and nitrogen was also detected on the bioleached surfaces by XPS. This was attributed to the deposition, on the mineral surfaces, of the remnants of a bio-film consisting of an extra-cellular polymer layer that had favoured the bacterial action. © Springer-Verlag 2011

Combined PIXE and XPS analysis on republican and imperial Roman coins

NASA Astrophysics Data System (ADS)

Daccà, A.; Prati, P.; Zucchiatti, A.; Lucarelli, F.; Mandò, P. A.; Gemme, G.; Parodi, R.; Pera, R.

2000-03-01

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.

Rondorfite-type structure — XPS and UV–vis study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dulski, M., E-mail: mateusz.dulski@smcebi.edu.pl; A.Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice; Bilewska, K., E-mail: kbilewska@us.edu.pl

2015-10-15

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{sup 3+}/Al{sup 3+} formore » Mg{sup 2+}, the presence of atypical [MgO{sub 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{sup 2+} and isomorphic substitution of Al{sup 3+}/Fe{sup 3+} for Mg{sup 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.« less

Characterization of fossil remains using XRF, XPS and XAFS spectroscopies

NASA Astrophysics Data System (ADS)

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

2016-05-01

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.

XPS-XRF hybrid metrology enabling FDSOI process

NASA Astrophysics Data System (ADS)

Hossain, Mainul; Subramanian, Ganesh; Triyoso, Dina; Wahl, Jeremy; Mcardle, Timothy; Vaid, Alok; Bello, A. F.; Lee, Wei Ti; Klare, Mark; Kwan, Michael; Pois, Heath; Wang, Ying; Larson, Tom

2016-03-01

Planar fully-depleted silicon-on-insulator (FDSOI) technology potentially offers comparable transistor performance as FinFETs. pFET FDOSI devices are based on a silicon germanium (cSiGe) layer on top of a buried oxide (BOX). Ndoped interfacial layer (IL), high-k (HfO2) layer and the metal gate stacks are then successively built on top of the SiGe layer. In-line metrology is critical in precisely monitoring the thickness and composition of the gate stack and associated underlying layers in order to achieve desired process control. However, any single in-line metrology technique is insufficient to obtain the thickness of IL, high-k, cSiGe layers in addition to Ge% and N-dose in one single measurement. A hybrid approach is therefore needed that combines the capabilities of more than one measurement technique to extract multiple parameters in a given film stack. This paper will discuss the approaches, challenges, and results associated with the first-in-industry implementation of XPS-XRF hybrid metrology for simultaneous detection of high-k thickness, IL thickness, N-dose, cSiGe thickness and %Ge, all in one signal measurement on a FDSOI substrate in a manufacturing fab. Strong correlation to electrical data for one or more of these measured parameters will also be presented, establishing the reliability of this technique.

XUV Photometer System (XPS): New Dark-Count Corrections Model and Improved Data Products

NASA Astrophysics Data System (ADS)

Elliott, J. P.; Vanier, B.; Woods, T. N.

2017-12-01

We present newly updated dark-count calibrations for the SORCE XUV Photometer System (XPS) and the resultant improved data products released in March of 2017. The SORCE mission has provided a 14-year solar spectral irradiance record, and the XPS contributes to this record in the 0.1 nm to 40 nm range. The SORCE spacecraft has been operating in what is known as Day-Only Operations (DO-Op) mode since February of 2014. In this mode it is not possible to collect data, including dark-counts, when the spacecraft is in eclipse as we did prior to DO-Op. Instead, we take advantage of the position of the XPS filter-wheel, and collect these data when the wheel position is in a "dark" position. Further, in this mode dark data are not always available for all observations, requiring an extrapolation in order to calibrate data at these times. To extrapolate, we model this with a piece-wise 2D nonlinear least squares surface fit in the time and temperature dimensions. Our model allows us to calibrate XPS data into the DO-Op phase of the mission by extrapolating along this surface. The XPS version 11 data product release benefits from this new calibration. We present comparisons of the previous and current calibration methods in addition to planned future upgrades of our data products.

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

NASA Astrophysics Data System (ADS)

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.

Surface Coverage and Structure of Mixed DNA/Alkylthiol Monolayers on Gold: Characterization by XPS, NEXAFS, and Fluorescence Intensity Measurements

PubMed Central

Lee, Chi-Ying; Gong, Ping; Harbers, Gregory M.; Grainger, David W.; Castner, David G.; Gamble, Lara J.

2006-01-01

Self-assembly of thiol-terminated single-stranded DNA (HS-ssDNA) on gold has served as an important model system for DNA immobilization at surfaces. Here, we report a detailed study of the surface composition and structure of mixed self-assembled DNA monolayers containing a short alkylthiol surface diluent [11-mercapto-1-undecanol (MCU)] on gold supports. These mixed DNA monolayers were studied with X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS), and fluorescence intensity measurements. XPS results on sequentially adsorbed DNA/MCU monolayers on gold indicated that adsorbed MCU molecules first incorporate into the HS-ssDNA monolayer and, upon longer MCU exposures, displace adsorbed HS-ssDNA molecules from the surface. Thus, HS-ssDNA surface coverage steadily decreased with MCU exposure time. Polarization-dependent NEXAFS and fluorescence results both show changes in signals consistent with changes in DNA orientation after only 30 min of MCU exposure. NEXAFS polarization dependence (followed by monitoring the N 1s → π* transition) of the mixed DNA monolayers indicated that the DNA nucleotide base ring structures are oriented more parallel to the gold surface compared to DNA bases in pure HS-ssDNA monolayers. This indicates that HS-ssDNA oligomers reorient toward a more-upright position upon MCU incorporation. Fluorescence intensity results using end-labeled DNA probes on gold show little observable fluorescence on pure HS-ssDNA monolayers, likely due to substrate quenching effects between the fluorophore and the gold. MCU diluent incorporation into HS-ssDNA monolayers initially increases DNA fluorescence signal by densifying the chemisorbed monolayer, prompting an upright orientation of the DNA, and moving the terminal fluorophore away from the substrate. Immobilized DNA probe density and DNA target hybridization in these mixed DNA monolayers, as well as effects of MCU diluent on DNA hybridization in complex

Surface Characterization of Polymer Blends by XPS and ToF-SIMS

PubMed Central

Chan, Chi Ming; Weng, Lu-Tao

2016-01-01

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. PMID:28773777

Effects of the low Earth orbit space environment on the surface chemistry of Kapton polyimide film: An XPS study

NASA Technical Reports Server (NTRS)

Lee, Myung; Rooney, William; Whiteside, James

1992-01-01

Kapton H (DuPont Trademark) polyimide specimens exposed to the low earth (LEO) space environment suffered significant weathering with surface erosions of approximately 8.0 microns. Despite these effects, no significant changes in bulk chemistry were observed. X-ray photoelectron spectroscopy (XPS) was used to determine local changes induced from approximately 25 percent in 1980 vintage ground control specimens to nearly 53 percent in space exposed specimens. The greatest increase was observed for the divalent oxygen moieties, although a slight increase in carbonyl oxygen was also measured. Furthermore, the chemical shifts of all XPS peaks of space-exposed Kapton are shifted to higher energy. This is consistent with a higher oxidation state of the space exposed surface. Finally, space exposed specimens had distinct silicon peaks (2p 100 eV and 2s 149 eV) in their XPS spectra in agreement with widespread reports of silicon contamination throughout the LDEF satellite. These results are discussed in terms of surface reactivity of the polyimide exposed to the LEO environment and the chemical nature of contaminants deposited on flight surfaces due to satellite outgassing.

Interfaces in heterogeneous catalytic reactions: Ambient pressure XPS as a tool to unravel surface chemistry

DOE PAGES

Palomino, Robert M.; Hamlyn, Rebecca; Liu, Zongyuan; ...

2017-04-27

In this paper we provide a summary of the recent development of ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and its application to catalytic surface chemistry. The methodology as well as significant advantages and challenges associated with this novel technique are described. Details about specific examples of using AP-XPS to probe surface chemistry under working reaction conditions for a number of reactions are explained: CO oxidation, water-gas shift (WGS), CO 2 hydrogenation, dry reforming of methane (DRM) and ethanol steam reforming (ESR). In conclusion, we discuss insights into the future development of the AP-XPS technique and its applications.

Interfaces in heterogeneous catalytic reactions: Ambient pressure XPS as a tool to unravel surface chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palomino, Robert M.; Hamlyn, Rebecca; Liu, Zongyuan

In this paper we provide a summary of the recent development of ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and its application to catalytic surface chemistry. The methodology as well as significant advantages and challenges associated with this novel technique are described. Details about specific examples of using AP-XPS to probe surface chemistry under working reaction conditions for a number of reactions are explained: CO oxidation, water-gas shift (WGS), CO 2 hydrogenation, dry reforming of methane (DRM) and ethanol steam reforming (ESR). In conclusion, we discuss insights into the future development of the AP-XPS technique and its applications.

Upgrade of the Surface Spectrometer at NEPOMUC for PAES, XPS and STM Investigations

NASA Astrophysics Data System (ADS)

Zimnik, S.; Lippert, F.; Hugenschmidt, C.

2014-04-01

The characterization of the elemental composition of surfaces is of great importance for the understanding of many surface processes, such as surface segregation or oxidation. Positron-annihilation-induced Auger Electron Spectroscopy (PAES) is a powerful technique for gathering information about the elemental composition of only the topmost atomic layer of a sample. The upgraded surface spectrometer at NEPOMUC (NEtron induced POsitron source MUniCh) enables a comprehensive surface analysis with the complementary techniques STM, XPS and PAES. A new X-ray source for X-ray induced photoelectron spectroscopy (XPS) was installed to gather additional information on oxidation states. A new scanning tunneling microscope (STM) is used as a complementary method to investigate with atomic resolution the surface electron density. The combination of PAES, XPS and STM allows the characterization of both the elemental composition, and the surface topology.

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

NASA Astrophysics Data System (ADS)

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gavrielides, A.; Duguet, T., E-mail: thomas.duguet@ensiacet.fr, E-mail: Paul.Bagus@unt.edu; Esvan, J.

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 accuratemore » 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.« less

The adsorption of methyl iodide on uranium and uranium dioxide: Surface characterization using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES)

NASA Astrophysics Data System (ADS)

Dillard, J. G.; Moers, H.; Klewe-Nebenius, H.; Kirch, G.; Pfennig, G.; Ache, H. J.

1984-09-01

The adsorption of methyl iodide on uranium and on uranium dioxide has been studied at 25 °C. Surfaces of the substrates were characterized before and after adsorption by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The XPS binding energy results indicate that CH 3I adsorption on uranium yields a carbide-type carbon, UC, and uranium iodide, UI 3. On uranium dioxide the carbon electron binding energy measurements are consistent with the formation of a hydrocarbon, —CH 3-type moiety. The interpretation of XPS and AES spectral features for CH 3I adsorption on uranium suggest that a complex dissociative adsorption reaction takes place. Adsorption of CH 3I on UO 2 occurs via a dissociative process. Saturation coverage occurs on uranium at approximately two langmuir (1 L = 10 -6 Torr s) exposure whereas saturation coverage on uranium dioxide is found at about five langmuir.

A first-principles core-level XPS study on the boron impurities in germanium crystal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamauchi, Jun; Yoshimoto, Yoshihide; Suwa, Yuji

2013-12-04

We systematically investigated the x-ray photoelectron spectroscopy (XPS) core-level shifts and formation energies of boron defects in germanium crystals and compared the results to those in silicon crystals. Both for XPS core-level shifts and formation energies, relationship between defects in Si and Ge is roughly linear. From the similarity in the formation energy, it is expected that the exotic clusters like icosahedral B12 exist in Ge as well as in Si.

XPS studies of nitrogen doping niobium used for accelerator applications

NASA Astrophysics Data System (ADS)

Yang, Ziqin; Lu, Xiangyang; Tan, Weiwei; Zhao, Jifei; Yang, Deyu; Yang, Yujia; He, Yuan; Zhou, Kui

2018-05-01

Nitrogen doping study on niobium (Nb) samples used for the fabrication of superconducting radio frequency (SRF) cavities was carried out. The samples' surface treatment was attempted to replicate that of the Nb SRF cavities, which includes heavy electropolishing (EP), nitrogen doping and the subsequent EP with different amounts of material removal. The surface chemical composition of Nb samples with different post treatments has been studied by XPS. The chemical composition of Nb, O, C and N was presented before and after Gas Cluster Ion Beam (GCIB) etching. No signals of poorly superconducting nitrides NbNx was found on the surface of any doped Nb sample with the 2/6 recipe before GCIB etching. However, in the depth range greater than 30 nm, the content of N element is below the XPS detection precision scope even for the Nb sample directly after nitrogen doping treatment with the 2/6 recipe.

A Key Major Guideline for Engineering Bioactive Multicomponent Nanofunctionalization for Biomedicine and Other Applications: Fundamental Models Confirmed by Both Direct and Indirect Evidence

PubMed Central

Scherrieble, Andreas; Bahrizadeh, Shiva; Avareh Sadrabadi, Fatemeh; Hedayat, Laleh

2017-01-01

This paper deals with the engineering multicomponent nanofunctionalization process considering fundamental physicochemical features of nanostructures such as surface energy, chemical bonds, and electrostatic interactions. It is pursued by modeling the surface nanopatterning and evaluating the proposed technique and the models. To this end, the effects of surface modifications of nanoclay on surface interactions, orientations, and final features of TiO2/Mt nanocolloidal textiles functionalization have been investigated. Various properties of cross-linkable polysiloxanes (XPs) treated samples as well as untreated samples with XPs have been compared to one another. The complete series of samples have been examined in terms of bioactivity and some physical properties, given to provide indirect evidence on the surface nanopatterning. The results disclosed a key role of the selected factors on the final features of treated surfaces. The effects have been thoroughly explained and modeled according to the fundamental physicochemical features. The developed models and associated hypotheses interestingly demonstrated a full agreement with all measured properties and were appreciably confirmed by FESEM evidence (direct evidence). Accordingly, a guideline has been developed to facilitate engineering and optimizing the pre-, main, and post-multicomponent nanofunctionalization procedures in terms of fundamental features of nanostructures and substrates for biomedical applications and other approaches. PMID:29333437

New Pt/Alumina model catalysts for STM and in situ XPS studies

NASA Astrophysics Data System (ADS)

Nartova, Anna V.; Gharachorlou, Amir; Bukhtiyarov, Andrey V.; Kvon, Ren I.; Bukhtiyarov, Valerii I.

2017-04-01

The new Pt/alumina model catalysts for STM and in situ XPS studies based on thin alumina film formed over the conductive substrate are proposed. Procedure of platinum deposition developed for porous alumina was adapted for the model alumina support. The set of Pt/AlOx-film samples with the different mean platinum particle size was prepared. Capabilities of in situ XPS investigations of the proposed catalysts were demonstrated in study of NO decomposition on platinum nanoparticles. It is shown that proposed model catalysts behave similarly to Pt/γ-Al2O3 and provide the new opportunities for the instrumental studies of platinum catalysts due to resolving several issues (charging, heating, screening) that are typical for the investigation of the porous oxide supported catalysts.

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

PubMed

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.

XPS and UPS studies on electronic structure of Li 2O

NASA Astrophysics Data System (ADS)

Tanaka, Satoru; Taniguchi, Masaki; Tanigawa, Hisashi

2000-12-01

The adsorption behavior of H 2O on Li 2O was studied by X-ray photo electron spectroscopy (XPS) and ultraviolet photo electron spectroscopy (UPS). XPS and UPS spectra of Li 2O single crystals which were exposed to different pressure of H 2O vapor were observed. In O(1s) region, two peaks were observed and they were assigned to O(1s) in precipitated LiOH on the surface and O(1s) in Li 2O. After H 2O exposure, a peak broadening and an appearance of a new peak were observed at the higher binding energy region than O(1s) in Li 2O. They were attributed to surface -OH and H 2O molecule adsorbed on the surface. The adsorption behavior of H 2O was discussed from the observation of electronic structure in Li 2O surface.

RECENT XPS STUDIES OF THE EFFECT OF PROCESSING ON NB SRF SURFACES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hui Tian; Binping Xiao; Michael Kelley

XPS studies have consistently shown that Nb surfaces for SRF chiefly comprise of a few nm of Nb2O5 on top of Nb metal, with minor amounts of Nb sub-oxides. Nb samples after BCP/EP treatment with post-baking at the various conditions have been examined by using synchrotron based XPS. Despite the confounding influence of surface roughness, certain outcomes are clear. Lower-valence Nb species are always and only associated with the metal/oxide interface, but evidence for an explicit layer structure or discrete phases is lacking. Post-baking without air exposure shows decreased oxide layer thickness and increased contribution from lower valence species, butmore » spectra obtained after subsequent air exposure cannot be distinguished from those obtained prior to baking, though the SRF performance improvement remains.« less

Reaction of Si nanopowder with water investigated by FT-IR and XPS

NASA Astrophysics Data System (ADS)

Imamura, Kentaro; Kobayashi, Yuki; Matsuda, Shinsuke; Akai, Tomoki; Kobayashi, Hikaru

2017-08-01

The initial reaction of Si nanopowder with water to generate hydrogen is investigated using FT-IR and XPS measurements. Si nanopowder is fabricated using the simple beads milling method. For HF-etched Si nanopowder, strong peaks due to Si-H and Si-H2 stretching vibrational modes and a weak shoulder peak due to Si-H3 are observed. Although no peaks due to oxide is observed in the Si 2p XPS spectrum, weak vibrational peaks due to HSiO2 and HSiO3 species are observable. The hydrogen generation rate greatly increases with pH, indicating that the reacting species is hydroxide ions (OH- ions). After the reaction, the intensities of the peaks due to SiH and SiH2 species decrease while those for HSiO, HSiO2, and HSiO3 species increase. This result demonstrates that OH- ions attack Si back-bonds, with surface Si-H bonds remaining. After initial reaction of HF-etched Si nanopowder with heavy water, vibrational peaks for SiD, SiDH, and SiDH2 appear, and then, a peak due to DSiO3 species is observed, but no peaks due to DSiO2 and DSiO species are observable. This result indicates that SiD, SiDH, and SiDH2 species are formed by substitution reactions, followed by oxidation of back-bonds to form DSiO3 species. After immersion in D2O for a day, 37% H atoms on the surface are replaced to D atoms.

Confirming criticality safety of TRU waste with neutron measurements and risk analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winn, W.G.; Hochel, R.D.

1992-04-01

The criticality safety of {sup 239}Pu in 55-gallon drums stored in TRU waste containers (culverts) is confirmed using NDA neutron measurements and risk analyses. The neutron measurements yield a {sup 239}Pu mass and k{sub eff} for a culvert, which contains up to 14 drums. Conservative probabilistic risk analyses were developed for both drums and culverts. Overall {sup 239}Pu mass estimates are less than a calculated safety limit of 2800 g per culvert. The largest measured k{sub eff} is 0.904. The largest probability for a critical drum is 6.9 {times} 10{sup {minus}8} and that for a culvert is 1.72 {times} 10{supmore » {minus}7}. All examined suspect culverts, totaling 118 in number, are appraised as safe based on these observations.« less

Samarium electrodeposited acetate and oxide thin films on stainless steel substrate characterized by XPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myhre, Kristian; Burns, Jonathan; Meyer, Harry

Characterization of a samarium thin film deposited on a stainless steel substrate using molecular electrodeposition was carried out using a Thermo Scientific K-Alpha X-ray photoelectron spectrometer. We studied two types of samarium electrodeposition samples, one as-deposited and one heated to 700 °C in an air flow. Survey scans include peaks coming from the stainless steel substrate, such as Fe and Cr. An X-ray photoelectron spectroscopy (XPS) survey spectrum, Sm 3d, C 1s, and O 1s narrow scans are shown. It was determined that the heating process decomposed the deposited Sm acetate to Sm 2O 3 using XPS.

Samarium electrodeposited acetate and oxide thin films on stainless steel substrate characterized by XPS

DOE PAGES

Myhre, Kristian; Burns, Jonathan; Meyer, Harry; ...

2016-06-01

Characterization of a samarium thin film deposited on a stainless steel substrate using molecular electrodeposition was carried out using a Thermo Scientific K-Alpha X-ray photoelectron spectrometer. We studied two types of samarium electrodeposition samples, one as-deposited and one heated to 700 °C in an air flow. Survey scans include peaks coming from the stainless steel substrate, such as Fe and Cr. An X-ray photoelectron spectroscopy (XPS) survey spectrum, Sm 3d, C 1s, and O 1s narrow scans are shown. It was determined that the heating process decomposed the deposited Sm acetate to Sm 2O 3 using XPS.

Silicon (100)/SiO2 by XPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, David S.; Kanyal, Supriya S.; Madaan, Nitesh

2013-09-25

Silicon (100) wafers are ubiquitous in microfabrication and, accordingly, their surface characteristics are important. Herein, we report the analysis of Si (100) via X-ray photoelectron spectroscopy (XPS) using monochromatic Al K radiation. Survey scans show that the material is primarily silicon and oxygen, and the Si 2p region shows two peaks that correspond to elemental silicon and silicon dioxide. Using these peaks the thickness of the native oxide (SiO2) was estimated using the equation of Strohmeier.1 The oxygen peak is symmetric. The material shows small amounts of carbon, fluorine, and nitrogen contamination. These silicon wafers are used as the basemore » material for subsequent growth of templated carbon nanotubes.« less

Reduction of mixed Mn-Zr oxides: in situ XPS and XRD studies.

PubMed

Bulavchenko, O A; Vinokurov, Z S; Afonasenko, T N; Tsyrul'nikov, P G; Tsybulya, S V; Saraev, A A; Kaichev, V V

2015-09-21

A series of mixed Mn-Zr oxides with different molar ratios Mn/Zr (0.1-9) have been prepared by coprecipitation of manganese and zirconium nitrates and characterized by X-ray diffraction (XRD) and BET methods. It has been found that at concentrations of Mn below 30 at%, the samples are single-phase solid solutions (MnxZr1-xO2-δ) based on a ZrO2 structure. X-ray photoelectron spectroscopy (XPS) measurements showed that manganese in these solutions exists mainly in the Mn(4+) state on the surface. An increase in Mn content mostly leads to an increase in the number of Mn cations in the structure of solid solutions; however, a part of the manganese cations form Mn2O3 and Mn3O4 in the crystalline and amorphous states. The reduction of these oxides with hydrogen was studied by a temperature-programmed reduction technique, in situ XRD, and near ambient pressure XPS in the temperature range from 100 to 650 °C. It was shown that the reduction of the solid solutions MnxZr1-xO2-δ proceeds via two stages. During the first stage, at temperatures between 100 and 500 °C, the Mn cations incorporated into the solid solutions MnxZr1-xO2-δ undergo partial reduction. During the second stage, at temperatures between 500 and 700 °C, Mn cations segregate on the surface of the solid solution. In the samples with more than 30 at% Mn, the reduction of manganese oxides was observed: Mn2O3 → Mn3O4 → MnO.

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

NASA Astrophysics Data System (ADS)

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.

Highly efficient removal of heavy metals by polymer-supported nanosized hydrated Fe(III) oxides: behavior and XPS study.

PubMed

Pan, Bingjun; Qiu, Hui; Pan, Bingcai; Nie, Guangze; Xiao, Lili; Lv, Lu; Zhang, Weiming; Zhang, Quanxing; Zheng, Shourong

2010-02-01

The present study developed a polymer-based hybrid sorbent (HFO-001) for highly efficient removal of heavy metals [e.g., Pb(II), Cd(II), and Cu(II)] by irreversibly impregnating hydrated Fe(III) oxide (HFO) nanoparticles within a cation-exchange resin D-001 (R-SO(3)Na), and revealed the underlying mechanism based on X-ray photoelectron spectroscopy (XPS) study. HFO-001 combines the excellent handling, flow characteristics, and attrition resistance of conventional cation-exchange resins with the specific affinity of HFOs toward heavy metal cations. As compared to D-001, sorption selectivity of HFO-001 toward Pb(II), Cu(II), and Cd(II) was greatly improved from the Ca(II) competition at greater concentration. Column sorption results indicated that the working capacity of HFO-001 was about 4-6 times more than D-001 with respect to removal of three heavy metals from simulated electroplating water (pH approximately 4.0). Also, HFO-001 is particularly effective in removing trace Pb(II) and Cd(II) from simulated natural waters to meet the drinking water standard, with treatment volume orders of magnitude higher than D-001. The superior performance of HFO-001 was attributed to the Donnan membrane effect exerted by the host D-001 as well as to the impregnated HFO nanoparticles of specific interaction toward heavy metal cations, as further confirmed by XPS study on lead sorption. More attractively, the exhausted HFO-001 beads can be effectively regenerated by HCl-NaCl solution (pH 3) for repeated use without any significant capacity loss. (c) 2009 Elsevier Ltd. All rights reserved.

Measurement of bio-impedance with a smart needle to confirm percutaneous kidney access.

PubMed

Hernandez, D J; Sinkov, V A; Roberts, W W; Allaf, M E; Patriciu, A; Jarrett, T W; Kavoussi, L R; Stoianovici, D

2001-10-01

The traditional method of percutaneous renal access requires freehand needle placement guided by C-arm fluoroscopy, ultrasonography, or computerized tomography. This approach provides limited objective means for verifying successful access. We developed an impedance based percutaneous Smart Needle system and successfully used it to confirm collecting system access in ex vivo porcine kidneys. The Smart Needle consists of a modified 18 gauge percutaneous access needle with the inner stylet electrically insulated from the outer sheath. Impedance is measured between the exposed stylet tip and sheath using Model 4275 LCR meter (Hewlett-Packard, Sunnyvale, California). An ex vivo porcine kidney was distended by continuous gravity infusion of 100 cm. water saline from a catheter passed through the parenchyma into the collecting system. The Smart Needle was gradually inserted into the kidney to measure depth precisely using a robotic needle placement system, while impedance was measured continuously. The Smart Needle was inserted 4 times in each of 4 kidneys. When the needle penetrated the distended collecting system in 11 of 16 attempts, a characteristic sharp drop in resistivity was noted from 1.9 to 1.1 ohm m. Entry into the collecting system was confirmed by removing the stylet and observing fluid flow from the sheath. This characteristic impedance change was observed only at successful entry into the collecting system. A characteristic sharp drop in impedance signifies successful entry into the collecting system. The Smart Needle system may prove useful for percutaneous kidney access.

Stability of boron-doped graphene/copper interface: DFT, XPS and OSEE studies

NASA Astrophysics Data System (ADS)

Boukhvalov, D. W.; Zhidkov, I. S.; Kukharenko, A. I.; Slesarev, A. I.; Zatsepin, A. F.; Cholakh, S. O.; Kurmaev, E. Z.

2018-05-01

Two different types of boron-doped graphene/copper interfaces synthesized using two different flow rates of Ar through the bubbler containing the boron source were studied. X-ray photoelectron spectra (XPS) and optically stimulated electron emission (OSEE) measurements have demonstrated that boron-doped graphene coating provides a high corrosion resistivity of Cu-substrate with the light traces of the oxidation of carbon cover. The density functional theory calculations suggest that for the case of substitutional (graphitic) boron-defect only the oxidation near boron impurity is energetically favorable and creation of the vacancies that can induce the oxidation of copper substrate is energetically unfavorable. In the case of non-graphitic boron defects oxidation of the area, a nearby impurity is metastable that not only prevent oxidation but makes boron-doped graphene. Modeling of oxygen reduction reaction demonstrates high catalytic performance of these materials.

Investigating early stages of biocorrosion with XPS: AISI 304 stainless steel exposed to Burkholderia species

NASA Astrophysics Data System (ADS)

Johansson, Leena-Sisko; Saastamoinen, Tuomas

1999-04-01

We have investigated the interactions of an exopolymer-producing bacteria, Burkholderia sp. with polished AISI 304 stainless steel substrates using X-ray photoelectron spectroscopy (XPS). Steel coupons were exposed to the pure bacteria culture in a specially designed flowcell for 6 h during which the experiment was monitored in situ with an optical microscope. XPS results verified the formation of biofilm containing extracellular polymer on all the samples exposed to bacteria. Sputter results indicated that some ions needed for metabolic processes were trapped within the biofilm. Changes in the relative Fe concentration and Fe 2p peak shape indicated that also iron had accumulated into the biofilm.

Ultrathin TiO(x) films on Pt(111): a LEED, XPS, and STM investigation.

PubMed

Sedona, Francesco; Rizzi, Gian Andrea; Agnoli, Stefano; Llabrés i Xamena, Francesc X; Papageorgiou, Anthoula; Ostermann, Dieter; Sambi, Mauro; Finetti, Paola; Schierbaum, Klaus; Granozzi, Gaetano

2005-12-29

Ultrathin ordered titanium oxide films on Pt(111) surface are prepared by reactive evaporation of Ti in oxygen. By varying the Ti dose and the annealing conditions (i.e., temperature and oxygen pressure), six different long-range ordered phases are obtained. They are characterized by means of low-energy electron diffraction (LEED), X-ray photoemission spectroscopy (XPS), and scanning tunneling microscopy (STM). By careful optimization of the preparative parameters, we find conditions where predominantly single phases of TiO(x), revealing distinct LEED pattern and STM images, are produced. XPS binding energy and photoelectron diffraction (XPD) data indicate that all the phases, except one (the stoichiometric rect-TiO2), are one monolayer thick and composed of a Ti-O bilayer with interfacial Ti. Atomically resolved STM images confirm that these TiO(x) phases wet the Pt surface, in contrast to rect-TiO2. This indicates their interface stabilization. At a low Ti dose (0.4 monolayer equivalents, MLE), an incommensurate kagomé-like low-density phase (k-TiO(x) phase) is observed where hexagons are sharing their vertexes. At a higher Ti dose (0.8 MLE), two denser phases are found, both characterized by a zigzag motif (z- and z'-TiO(x) phases), but with distinct rectangular unit cells. Among them, z'-TiO(x), which is obtained by annealing in ultrahigh vacuum (UHV), shows a larger unit cell. When the postannealing of the 0.8 MLE deposit is carried out at high temperatures and high oxygen partial pressures, the incommensurate nonwetting, fully oxidized rect-TiO2 is found The symmetry and lattice dimensions are almost identical with rect-VO2, observed in the system VO(x)/Pd(111). At a higher coverage (1.2 MLE), two commensurate hexagonal phases are formed, namely the w- [(square root(43) x square root(43)) R 7.6 degrees] and w'-TiO(x) phase [(7 x 7) R 21.8 degrees]. They show wagon-wheel-like structures and have slightly different lattice dimensions. Larger Ti deposits

XPS Study of Oxide/GaAs and SiO2/Si Interfaces

NASA Technical Reports Server (NTRS)

Grunthaner, F. J.; Grunthaner, P. J.; Vasquez, R. P.; Lewis, B. F.; Maserjian, J.; Madhukar, A.

1982-01-01

Concepts developed in study of SiO2/Si interface applied to analysis of native oxide/GaAs interface. High-resolution X-ray photoelectron spectroscopy (XPS) has been combined with precise chemical-profiling technique and resolution-enhancement methods to study stoichiometry of transitional layer. Results are presented in report now available.

XPS analysis of activated carbon supported ionic liquids: Enhanced purity and reduced charging

NASA Astrophysics Data System (ADS)

Foelske-Schmitz, A.; Weingarth, D.; Kötz, R.

2011-12-01

Herein we report on XPS measurements on five different [EMIM] based ionic liquids (IL) prepared on activated carbon and aluminium supports. The anions were [TFSI], [BF4], [FAP], [B(CN)4] and [EtOSO3]. The results show that impurities such as O, Si or hydrocarbons were significantly reduced or no longer detected when preparation was performed on the high surface area carbon support. All core level spectra were fitted and for [EMIM][FAP], [EMIM][B(CN)4] and [EMIM][EtOSO3] de-convolution procedures of the C 1s lines are suggested. Comparison of the determined binding energies with published data strongly suggests that sample charging is irrelevant when preparation is performed on the activated carbon support. This observation is supposed to refer to the high capacitance of the high surface area carbon.

Confirmation of Incorporation of Cu and Se Ions in Applied p- and n-Type-Doped Sb2S3 by Photoemission Spectroscopy

NASA Astrophysics Data System (ADS)

Validžić, Ivana Lj; Popović, Maja; Lojpur, Vesna; Bundaleski, Nenad; Rakočević, Zlatko

2018-04-01

The effect of incorporating copper (Cu) and selenium (Se) ions into stibnite (Sb2S3) lattice was investigated using x-ray photoelectron spectroscopy (XPS). The incorporation of Cu and Se ions was verified by comparing the XPS spectra of the undoped (amorphous Sb2S3), doped ( p and n-doped) and pure Se and Cu-acetate powders. The main photoelectron Cu 2p1/2 (951.8 eV) and Cu 2p3/2 (932.1 eV) lines derived from the Cu-doped and Cu-acetate powder samples were clearly observed, whereas in the undoped sample, none of the characteristic lines of Cu were detected. The Se Auger line (138.6 eV), the only line of Se which does not coincide with the lines of Sb and S, was successfully detected in an Se-doped XPS sample and the spectrum of pure Se, while Se in the undoped sample was not found. Further, the XPS measurements revealed the relative amounts of Cu and Se in antimony sulfide, as well as the oxidation state of copper incorporated into the matrix.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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,more » 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.« less

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

PubMed

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.

XPS and EELS characterization of Mn2SiO4, MnSiO3 and MnAl2O4

NASA Astrophysics Data System (ADS)

Grosvenor, A. P.; Bellhouse, E. M.; Korinek, A.; Bugnet, M.; McDermid, J. R.

2016-08-01

X-ray Photoelectron Spectroscopy (XPS) and Electron Energy Loss Spectroscopy (EELS) are strong candidate techniques for characterizing steel surfaces and substrate-coating interfaces when investigating the selective oxidation and reactive wetting of advanced high strength steels (AHSS) during the continuous galvanizing process. However, unambiguous identification of ternary oxides such as Mn2SiO4, MnSiO3, and MnAl2O4 by XPS or EELS, which can play a significant role in substrate reactive wetting, is difficult due to the lack of fully characterized standards in the literature. To resolve this issue, samples of Mn2SiO4, MnSiO3 and MnAl2O4 were synthesized and characterized by XPS and EELS. The unique features of the XPS and EELS spectra for the Mn2SiO4, MnSiO3 and MnAl2O4 standards were successfully derived, thereby allowing investigators to fully differentiate and identify these oxides at the surface and subsurface of Mn, Si and Al alloyed AHSS using these techniques.

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

NASA Astrophysics Data System (ADS)

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.

Effects of Mn Ion Implantation on XPS Spectroscopy of GaN Thin Films

NASA Astrophysics Data System (ADS)

Majid, Abdul; Ahmad, Naeem; Rizwan, Muhammad; Khan, Salah Ud-Din; Ali, Fekri Abdulraqeb Ahmed; Zhu, Jianjun

2018-02-01

Gallium nitride (GaN) thin film was deposited onto a sapphire substrate and then implanted with 250 keV Mn ions at two different doses of 2 × 1016 ions/cm2 and 5 × 1016 ions/cm2. The as-grown and post-implantation-thermally-annealed samples were studied in detail using x-ray photoelectron spectroscopy (XPS). The XPS peaks of Ga 3 d, Ga 2 p, N 1 s, Mn 2 p and C 1 s were recorded in addition to a full survey of the samples. The doublet peaks of Ga 2 p for pure GaN were observed blue-shifted when compared with elemental Ga, and appeared further shifted to higher energies for the implanted samples. These observations point to changes in the bonds and the chemical environment of the host as a result of ion implantation. The results revealed broadening of the N 1 s peak after implantation, which is interpreted in terms of the presence of N-Mn bonds in addition to N-Ga bonds. The XPS spectra of Mn 2 p recorded for ion-implanted samples indicated splitting of Mn 2 p 1/2 and Mn 2 p 3/2 peaks higher than that for metallic Mn, which helps rule out the possibility of clustering and points to substitutional doping of Mn. These observations provide a framework that sheds light on the local environment of the material for understanding the mechanism of magnetic exchange interactions in Mn:GaN based diluted magnetic semiconductors.

Surface composition XPS analysis of a plasma treated polystyrene: Evolution over long storage periods.

PubMed

Ba, Ousmane M; Marmey, Pascal; Anselme, Karine; Duncan, Anthony C; Ponche, Arnaud

2016-09-01

A polystyrene surface (PS) was initially treated by cold nitrogen and oxygen plasma in order to incorporate in particular amine and hydroxyl functions, respectively. The evolution of the chemical nature of the surface was further monitored over a long time period (580 days) by chemical assay, XPS and contact angle measurements. Surface density quantification of primary amine groups was performed using three chemical amine assays: 4-nitrobenzaldehyde (4-NBZ), Sulfo succinimidyl 6-[3'(2 pyridyldithio)-pionamido] hexanoate (Sulfo-LC-SPDP) and iminothiolane (ITL). The results showed amine densities were in the range of 2 per square nanometer (comparable to the results described in the literature) after 5min of nitrogen plasma treatment. Over the time period investigated, chemical assays, XPS and contact angles suggest a drastic significant evolution of the chemical nature of the surface within the first two weeks. Beyond that time period and up to almost two years, nitrogen plasma modified substrates exhibits a slow and continuous oxidation whereas oxygen plasma modifed polystyrene surface is chemically stable after two weeks of storage. The latter appeared to "ease of" showing relatively mild changes within the one year period. Our results suggest that it may be preferable to wait for a chemical "stabilization" period of two weeks before subsequent covalent immobilization of proteins onto the surface. The originality of this work resides in the study of the plasma treated surface chemistry evolution over long periods of storage time (580 days) considerably exceeding those described in the literature. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparative study of the native oxide on 316L stainless steel by XPS and ToF-SIMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tardio, Sabrina, E-mail: s.tardio@surrey.ac.uk; Abel, Marie-Laure; Castle, James E.

2015-09-15

The very thin native oxide film on stainless steel, of the order of 2 nm, is known to be readily modified by immersion in aqueous media. In this paper, X-ray photoelectron spectroscopy (XPS) and time of flight secondary ions mass spectrometry are employed to investigate the nature of the air-formed film and modification after water emersion. The film is described in terms of oxide, hydroxide, and water content. The preferential dissolution of iron is shown to occur on immersion. It is shown that a water absorbed layer and a hydroxide layer are present above the oxide-like passive film. The concentrations ofmore » water and hydroxide appear to be higher in the case of exposure to water. A secure method for the peak fitting of Fe2p and Cr2p XPS spectra of such films on their metallic substrates is described. The importance of XPS survey spectra is underlined and the feasibility of C{sub 60}{sup +} SIMS depth profiling of a thin oxide layer is shown.« less

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

NASA Astrophysics Data System (ADS)

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.

Evaluation Metrics for the Paragon XP/S-15

NASA Technical Reports Server (NTRS)

Traversat, Bernard; McNab, David; Nitzberg, Bill; Fineberg, Sam; Blaylock, Bruce T. (Technical Monitor)

1993-01-01

On February 17th 1993, the Numerical Aerodynamic Simulation (NAS) facility located at the NASA Ames Research Center installed a 224 node Intel Paragon XP/S-15 system. After its installation, the Paragon was found to be in a very immature state and was unable to support a NAS users' workload, composed of a wide range of development and production activities. As a first step towards addressing this problem, we implemented a set of metrics to objectively monitor the system as operating system and hardware upgrades were installed. The metrics were designed to measure four aspects of the system that we consider essential to support our workload: availability, utilization, functionality, and performance. This report presents the metrics collected from February 1993 to August 1993. Since its installation, the Paragon availability has improved from a low of 15% uptime to a high of 80%, while its utilization has remained low. Functionality and performance have improved from merely running one of the NAS Parallel Benchmarks to running all of them faster (between 1 and 2 times) than on the iPSC/860. In spite of the progress accomplished, fundamental limitations of the Paragon operating system are restricting the Paragon from supporting the NAS workload. The maximum operating system message passing (NORMA IPC) bandwidth was measured at 11 Mbytes/s, well below the peak hardware bandwidth (175 Mbytes/s), limiting overall virtual memory and Unix services (i.e. Disk and HiPPI I/O) performance. The high NX application message passing latency (184 microns), three times than on the iPSC/860, was found to significantly degrade performance of applications relying on small message sizes. The amount of memory available for an application was found to be approximately 10 Mbytes per node, indicating that the OS is taking more space than anticipated (6 Mbytes per node).

Morphological, chemical and structural characterisation of deciduous enamel: SEM, EDS, XRD, FTIR and XPS analysis.

PubMed

Zamudio-Ortega, C M; Contreras-Bulnes, R; Scougall-Vilchis, R J; Morales-Luckie, R A; Olea-Mejía, O F; Rodríguez-Vilchis, L E

2014-09-01

The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.

XPS studies of MgO based magnetic tunnel junction structures

NASA Astrophysics Data System (ADS)

Read, John; Mather, Phil; Tan, Eileen; Buhrman, Robert

2006-03-01

The very high tunneling magnetoresistance (TMR) obtained in MgO magnetic tunnel junctions (MTJ)^(1,2) motivates the investigation of the electronic properties of the MgO barrier layer and the study of the ferromagnetic metal - MgO interface chemistry. Such large TMR values are predicted by theory due to the high degree of order apparent in the barrier and electrode materials. However, as grown ultra-thin MgO films generally contain defects that can influence electron transport properties through the creation of low energy states within the bulk MgO band-gap. We will report the results of x-ray photoelectron spectroscopy (XPS) studies of (001) textured ultra-thin MgO layers that are prepared by RF magnetron sputtering and electron beam evaporation on ordered ferromagnetic electrodes and in ordered MTJ structures with and without post growth vacuum annealing. XPS spectra for both MgO deposition techniques clearly indicate a surface oxygen species that is likely bound by defects in the oxide^(3) in half-formed junctions and improvements in MgO quality after counter electrode deposition. We will discuss our results regarding the chemical properties of the oxide and its interfaces directed towards possibly providing guidance to engineer improved MgO MTJ devices. [1] S.S.P. Parkin et. al., Nature Materials, 3, 862 (2004). [2] S. Yuasa et. al., Nature Materials, 3, 868 (2004). [3] E. Tan et. al. , Phys. Rev. B. , 71, 161401 (2005).

Composite targets in HiPIMS plasmas: Correlation of in-vacuum XPS characterization and optical plasma diagnostics

NASA Astrophysics Data System (ADS)

Layes, Vincent; Monje, Sascha; Corbella, Carles; Schulz-von der Gathen, Volker; von Keudell, Achim; de los Arcos, Teresa

2017-05-01

In-vacuum characterization of magnetron targets after High Power Impulse Magnetron Sputtering (HiPIMS) has been performed by X-ray photoelectron spectroscopy (XPS). Al-Cr composite targets (circular, 50 mm diameter) mounted in two different geometries were investigated: an Al target with a small Cr disk embedded at the racetrack position and a Cr target with a small Al disk embedded at the racetrack position. The HiPIMS discharge and the target surface composition were characterized in parallel for low, intermediate, and high power conditions, thus covering both the Ar-dominated and the metal-dominated HiPIMS regimes. The HiPIMS plasma was investigated using optical emission spectroscopy and fast imaging using a CCD camera; the spatially resolved XPS surface characterization was performed after in-vacuum transfer of the magnetron target to the XPS chamber. This parallel evaluation showed that (i) target redeposition of sputtered species was markedly more effective for Cr atoms than for Al atoms; (ii) oxidation at the target racetrack was observed even though the discharge ran in pure Ar gas without O2 admixture, the oxidation depended on the discharge power and target composition; and (iii) a bright emission spot fixed on top of the inserted Cr disk appeared for high power conditions.

The Gaussian-Lorentzian Sum, Product, and Convolution (Voigt) functions in the context of peak fitting X-ray photoelectron spectroscopy (XPS) narrow scans

NASA Astrophysics Data System (ADS)

Jain, Varun; Biesinger, Mark C.; Linford, Matthew R.

2018-07-01

X-ray photoelectron spectroscopy (XPS) is arguably the most important vacuum technique for surface chemical analysis, and peak fitting is an indispensable part of XPS data analysis. Functions that have been widely explored and used in XPS peak fitting include the Gaussian, Lorentzian, Gaussian-Lorentzian sum (GLS), Gaussian-Lorentzian product (GLP), and Voigt functions, where the Voigt function is a convolution of a Gaussian and a Lorentzian function. In this article we discuss these functions from a graphical perspective. Arguments based on convolution and the Central Limit Theorem are made to justify the use of functions that are intermediate between pure Gaussians and pure Lorentzians in XPS peak fitting. Mathematical forms for the GLS and GLP functions are presented with a mixing parameter m. Plots are shown for GLS and GLP functions with mixing parameters ranging from 0 to 1. There are fundamental differences between the GLS and GLP functions. The GLS function better follows the 'wings' of the Lorentzian, while these 'wings' are suppressed in the GLP. That is, these two functions are not interchangeable. The GLS and GLP functions are compared to the Voigt function, where the GLS is shown to be a decent approximation of it. Practically, both the GLS and the GLP functions can be useful for XPS peak fitting. Examples of the uses of these functions are provided herein.

Multicenter study on costs associated with two surgical procedures: GreenLight XPS 180 W versus the gold standard transurethral resection of the prostate.

PubMed

Benejam-Gual, J M; Sanz-Granda, A; Budía, A; Extramiana, J; Capitán, C

2014-01-01

To analyze the costs associated with two surgical procedures for lower urinary tract symptoms secondary to benign prostatic hyperplasia: GreenLight XPS 180¦W versus the gold standard transurethral resection of the prostate. A multicenter, retrospective cost study was carried out from the National Health Service perspective, over a 3-month time period. Costs were broken down into pre-surgical, surgical and post-surgical phases. Data were extracted from records of patients operated sequentially, with IPSS=15, Qmax=15 mL/seg and a prostate volume of 40-80mL, adding only direct healthcare costs (€, 2013) associated with the procedure and management of complications. A total of 79 patients sequentially underwent GL XPS (n: 39) or TURP (n: 40) between July and October, 2013. Clinical outcomes were similar (94.9% and 92.5%, GL XPS and TURP, respectively) without significant differences (P=.67). The average direct cost per patient was reduced by €114 in GL XPS versus TURP patients; the cost was higher in the surgical phase with GL XPS (difference: €1,209; P<.001) but was lower in the post-surgical phase (difference: €-1,351; P<.001). The GreenLight XPS 180-W laser system is associated with a reduction in costs with respect to transurethral resection of prostate in the surgical treatment of LUTS secondary to PBH. This reduction is due to a shorter inpatient length of stay that offsets the cost of the new technology. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

Quantitative analysis of Ni2+/Ni3+ in Li[NixMnyCoz]O2 cathode materials: Non-linear least-squares fitting of XPS spectra

NASA Astrophysics Data System (ADS)

Fu, Zewei; Hu, Juntao; Hu, Wenlong; Yang, Shiyu; Luo, Yunfeng

2018-05-01

Quantitative analysis of Ni2+/Ni3+ using X-ray photoelectron spectroscopy (XPS) is important for evaluating the crystal structure and electrochemical performance of Lithium-nickel-cobalt-manganese oxide (Li[NixMnyCoz]O2, NMC). However, quantitative analysis based on Gaussian/Lorentzian (G/L) peak fitting suffers from the challenges of reproducibility and effectiveness. In this study, the Ni2+ and Ni3+ standard samples and a series of NMC samples with different Ni doping levels were synthesized. The Ni2+/Ni3+ ratios in NMC were quantitatively analyzed by non-linear least-squares fitting (NLLSF). Two Ni 2p overall spectra of synthesized Li [Ni0.33Mn0.33Co0.33]O2(NMC111) and bulk LiNiO2 were used as the Ni2+ and Ni3+ reference standards. Compared to G/L peak fitting, the fitting parameters required no adjustment, meaning that the spectral fitting process was free from operator dependence and the reproducibility was improved. Comparison of residual standard deviation (STD) showed that the fitting quality of NLLSF was superior to that of G/L peaks fitting. Overall, these findings confirmed the reproducibility and effectiveness of the NLLSF method in XPS quantitative analysis of Ni2+/Ni3+ ratio in Li[NixMnyCoz]O2 cathode materials.

XPS and 31P NMR inquiry of Eu3+-induced structural modification in SnO-containing phosphate glass

NASA Astrophysics Data System (ADS)

Jiménez, José A.; Fachini, Esteban Rosim; Zhao, Chunqing

2018-07-01

The influence of Eu3+ doping on the structural properties of SnO-containing phosphate glass has been investigated by X-ray photoelectron spectroscopy (XPS) and 31P nuclear magnetic resonance (NMR) spectroscopy. Oxygen 1s XPS data indicates that the Eu3+ doping results in a higher concentration of non-bridging oxygens in the glass matrix, whereas 31P NMR shows an increase in the terminal phosphate chain tetrahedral units, i.e. the amount of Q1 sites with only one bridging oxygen. Accordingly, both techniques agree with a depolymerization effect induced by the Eu3+ ions. Further, XPS reveals that together with the Eu3+ doping, the presence of Sn4+ is supported while the presence of Eu2+ is also indicated. The structural changes are then indicated to be a consequence of redox chemistry between Sn2+ and Eu3+ promoting a transition of tin from Sn2+ with a role as network former to Sn4+ acting as network modifier in the glass system.

XPS investigation of depth profiling induced chemistry

NASA Astrophysics Data System (ADS)

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.

Intensity analysis of XPS spectra to determine oxide uniformity - Application to SiO2/Si interfaces

NASA Technical Reports Server (NTRS)

Vasquez, R. P.; Grunthaner, F. J.

1980-01-01

A simple method of determining oxide uniformity is derived which requires no knowlege of film thickness, escape depth, or film composition. The method involves only the measurement of oxide and substrate intensities and is illustrated by analysis of XPS spectral data for thin SiO2 films grown both thermally and by low-temperature chemical vapor deposition on monocrystalline Si. A region 20-30 A thick is found near the SiO2/Si interface on thermally oxidized samples which has an inelastic mean free path 35% less than that found in the bulk oxide. This is interpreted as being due to lattice mismatch resulting in a strained region which is structurally, but not stoichiometrically, distinct from the bulk oxide.

Quantitative depth profiling of Ce(3+) in Pt/CeO2 by in situ high-energy XPS in a hydrogen atmosphere.

PubMed

Kato, Shunsuke; Ammann, Markus; Huthwelker, Thomas; Paun, Cristina; Lampimäki, Markus; Lee, Ming-Tao; Rothensteiner, Matthäus; van Bokhoven, Jeroen A

2015-02-21

The redox property of ceria is a key factor in the catalytic activity of ceria-based catalysts. The oxidation state of well-defined ceria nanocubes in gas environments was analysed in situ by a novel combination of near-ambient pressure X-ray Photoelectron Spectroscopy (XPS) and high-energy XPS at a synchrotron X-ray source. In situ high-energy XPS is a promising new tool to determine the electronic structure of matter under defined conditions. The aim was to quantitatively determine the degree of cerium reduction in a nano-structured ceria-supported platinum catalyst as a function of the gas environment. To obtain a non-destructive depth profile at near-ambient pressure, in situ high-energy XPS analysis was performed by varying the kinetic energy of photoelectrons from 1 to 5 keV, and, thus, the probing depth. In ceria nanocubes doped with platinum, oxygen vacancies formed only in the uppermost layers of ceria in an atmosphere of 1 mbar hydrogen and 403 K. For pristine ceria nanocubes, no change in the cerium oxidation state in various hydrogen or oxygen atmospheres was observed as a function of probing depth. In the absence of platinum, hydrogen does not dissociate and, thus, does not lead to reduction of ceria.

XPS and Raman studies of Pt catalysts supported on activated carbon

NASA Astrophysics Data System (ADS)

Tyagi, Deepak; Varma, Salil; Bharadwaj, S. R.

2018-04-01

Activated carbon is a widely used support for dispersing noble metals in addition to its many applications. We have prepared platinum catalyst supported on activated carbon for HI decomposition reaction of I-S thermochemical process of hydrogen generation. These catalysts were characterized by XPS and Raman before and after using for the reaction. It was observed that platinum is present in zero oxidation state, while carbon is present is both sp2 and sp3 hybridized forms along with some amount of it bonded to oxygen.

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

NASA Astrophysics Data System (ADS)

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.

Theoretical value of Newtonian constant G confirmed by the International Bureau of Weights & Measures in Paris, France

NASA Astrophysics Data System (ADS)

Omerbashich, Mensur

2015-01-01

World oldest authority for scientific constants and the keeper of the original metre standard, the International Bureau of Weights and Measures (BIPM) in Paris, France has accomplished a historic confirmation of the Omerbashich's (first-ever) scientific prediction of value of the Newtonian gravitational constant G.

Structural model of homogeneous As–S glasses derived from Raman spectroscopy and high-resolution XPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golovchak, R.; Shpotyuk, O.; Mccloy, J. S.

2010-11-28

The structure of homogeneous bulk As x S 100- x (25 ≤ x ≤ 42) glasses, prepared by the conventional rocking–melting–quenching method, was investigated using high-resolution X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. It is shown that the main building blocks of their glass networks are regular AsS 3/2 pyramids and sulfur chains. In the S-rich domain, the existence of quasi-tetrahedral (QT) S = As(S 1/2) 3 units is deduced from XPS data, but with a concentration not exceeding ~3–5% of total atomic sites. Therefore, QT units do not appear as primary building blocks of the glass backbone in thesemore » materials, and an optimally-constrained network may not be an appropriate description for glasses when x < 40. Finally, it is shown that, in contrast to Se-based glasses, the ‘chain-crossing’ model is only partially applicable to sulfide glasses.« less

Dissolution of uranophane: An AFM, XPS, SEM and ICP study

NASA Astrophysics Data System (ADS)

Schindler, Michael; Freund, Michael; Hawthorne, Frank C.; Burns, Peter C.; Maurice, Patricia A.

2009-05-01

Dissolution experiments on single crystals of uranophane and uranophane-β, Ca(H 2O) 5[(UO 2)(SiO 3(OH)] 2, from the Shinkolobwe mine of the Democratic Republic of Congo, were done in an aqueous HCl solution of pH 3.5 for 3 h, in HCl solutions of pH 2 for 5, 10 and 30 min, and in Pb 2+-, Ba-, Sr-, Ca- and Mg-HCl solutions of pH 2 for 30 min. The basal surfaces of the treated uranophane crystals were examined using atomic-force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Solutions after dissolution experiments on single crystals and synthetic powders were analysed with inductively coupled plasma-optical emission spectroscopy (ICP-OES) and mass spectroscopy (ICP-MS). The morphology of the observed etch pits (measured by AFM) were compared to the morphology, predicted on the basis of the bond-valence deficiency of polyhedron chains along the edges of the basal surface. Etch pits form in HCl solutions of pH 2. Their decrease in depth with the duration of the dissolution experiment is explained with the stepwave dissolution model, which describes the lowering of the surrounding area of an etch pit with continuous waves of steps emanated from the etch pit into the rest of the crystal surface. Hillocks form in an HCl solution of pH 3.5, and the chemical composition of the surface (as indicated by XPS) shows that these hillocks are the result of the precipitation of a uranyl-hydroxy-hydrate phase. Well-orientated hillocks form on the surface of uranophane in a SrCl 2-HCl solution of pH 2. They are part of an aged silica coating of composition Si 2O 2(OH) 4(H 2O) n. An amorphous layer forms on the surface of uranophane in a MgCl 2-HCl solution of pH 2, which has a composition and structure similar to silicic acid. Small crystallites of uranyl-hydroxy-hydrate phases form on the surface of uranophane after treatment in Pb(NO 3) 2-HCl and BaCl 2-HCl solutions of pH 2. Dissolution experiments on synthetic uranophane powders

A Chemical View on X-ray Photoelectron Spectroscopy: the ESCA Molecule and Surface-to-Bulk XPS Shifts.

PubMed

Delesma, Francisco A; Van den Bossche, Maxime; Grönbeck, Henrik; Calaminici, Patrizia; Köster, Andreas M; Pettersson, Lars G M

2018-01-19

In this paper we remind the reader of a simple, intuitive picture of chemical shifts in X-ray photoelectron spectroscopy (XPS) as the difference in chemical bonding between the probed atom and its neighbor to the right in the periodic table, the so called Z+1 approximation. We use the classical ESCA molecule, ethyl trifluoroacetate, and 4d-transition metals to explicitly demonstrate agreement between core-level shifts computed as differences between final core-hole states and the approach where each core-ionized atom is replaced by a Z+1 atom. In this final state, or total energy picture, the XPS shift arises due to the more or less unfavorable chemical bonding of the effective nitrogen in the carbon geometry for the ESCA molecule. Surface core level shifts in metals are determined by whether the Z+1 atom as an alloy segregates to the surface or is more soluble in the bulk. As further illustration of this more chemical picture, we compare the geometry of C 1s and O 1s core-ionized CO with that of, respectively, NO + and CF + . The scope is not to propose a new method to compute XPS shifts but rather to stress the validity of this simple interpretation. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Proton transfer and hydrogen bonding in the organic solid state: a combined XRD/XPS/ssNMR study of 17 organic acid-base complexes.

PubMed

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.

Spectroellipsometric, AFM and XPS probing of stainless steel surfaces subjected to biological influences

NASA Astrophysics Data System (ADS)

Vinnichenko, M.; Chevolleau, Th; Pham, M. T.; Poperenko, L.; Maitz, M. F.

2002-11-01

Surface modification of austenitic stainless steel (SS) 316L after incubation in growing cell cultures and cell-free media as control has been studied. The following treatments were applied: mouse fibrosarcoma cells L929 for 3 and 7 days, polymorphonuclear neutrophils for 3 and 7 days and human osteosarcoma cells SAOS-2 for 7 and 14 days. Cells were enzymatically removed in all cases. The modified surfaces were probed in comparison with untreated ones by means of spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). XPS shows the appearance of the peak of bonded nitrogen at 400.5 eV characteristic for adsorbed proteins on the surface for each type of cells and for the cell-free medium. Migration of Ni in the adsorbed layer is observed in all cases for samples after the cell cultures. The protein layer thickness is ellipsometrically determined to be within 2.5-6.0 nm for all treated samples with parameterization of its optical constants in Cauchy approach. The study showed that for such biological treatments of the SS the protein layer adsorption is the dominating process in the first 2 weeks, which could play a role in the process of corrosion by complex forming properties with metal ions.

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

NASA Astrophysics Data System (ADS)

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.

Chemical Visualization of a GaN p-n junction by XPS

PubMed Central

Caliskan, Deniz; Sezen, Hikmet; Ozbay, Ekmel; Suzer, Sefik

2015-01-01

We report on an operando XPS investigation of a GaN diode, by recording the Ga2p3/2 peak position under both forward and reverse bias. Areal maps of the peak positions under reverse bias are completely decoupled with respect to doped regions and allow a novel chemical visualization of the p-n junction in a 2-D fashion. Other electrical properties of the device, such as leakage current, resistivity of the domains are also tapped via recording line-scan spectra. Application of a triangular voltage excitation enables probing photoresponse of the device. PMID:26359762

Quantifying the Impact of Nanoparticle Coatings and Non-uniformities on XPS Analysis: Gold/silver Core-shell Nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yung-Chen Andrew; Engelhard, Mark H.; Baer, Donald R.

2016-03-07

Abstract or short description: 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, non-circular, and contain off-centered Au-cores. Using the average NP dimensions determined from STEM analysis,more » SESSA spectral modeling indicated that washed Au/Ag-core shell NPs were stabilized with a 0.8 nm l« less

Student-to-Student Confirmation in the College Classroom: The Development and Validation of the Student-to-Student Confirmation Scale

ERIC Educational Resources Information Center

LaBelle, Sara; Johnson, Zac D.

2018-01-01

Three studies were conducted to generate a valid and reliable instrument to measure student-to-student confirmation. Study One (N = 396) sought to establish a factor structure based on previous research. Study Two (N = 396) sought to confirm this factor structure and assess criterion-related validity. Study Three (N = 283) sought to assess…

XPS study of ruthenium tris-bipyridine electrografted from diazonium salt derivative on microcrystalline boron doped diamond.

PubMed

Agnès, Charles; Arnault, Jean-Charles; Omnès, Franck; Jousselme, Bruno; Billon, Martial; Bidan, Gérard; Mailley, Pascal

2009-12-28

Boron doped diamond (BDD) functionalization has received an increasing interest during the last few years. Such an infatuation comes from the original properties of BDD, including chemical stability or an electrochemical window, that opens the way for the design of (bio)sensors or smart interfaces. In such a context, diazonium salts appear to be well suited for BDD functionalization as they enable covalent immobilization of functional entities such as enzymes or DNA. In this study we report microcrystalline BDD functionalization with a metallic complex, ruthenium tris(bipyridine), using the p-(tris(bipyridine)Ru(2+))phenyl diazonium salt. Electrografting using cyclic voltammetry (CV) allowed the formation of a ruthenium complex film that was finely characterized using electrochemistry and X-ray photoelectron spectroscopy (XPS). Moreover, we showed that chronopotentiometry (CP) is a convenient tool to monitor Ru complex film deposition through the control of the electrochemical pulse parameters (i.e. current density and pulse duration). Finally, such a control was demonstrated through the correlation between electrochemical and XPS characterizations.

Surface and electronic structure of Bi-Ca-Sr-Cu-O superconductors studied by LEED, UPS and XPS

NASA Astrophysics Data System (ADS)

Shen, Z.-X.; Lindberg, P. A. P.; Wells, B. O.; Lindau, I.; Spicer, W. E.; Mitzi, D. B.; Eom, C. B.; Kapitulnik, A.; Geballe, T. H.; Soukiassian, P.

1989-02-01

Single crystal and polycrystalline samples of Bi2CaSr2Cu2O8 have been studied by various surface sensitive techniques, including low energy electron diffraction (LEED), ultraviolet photoemission spectroscopy (UPS) and x-ray photoemission spectroscopy (XPS). The surface structure of the single crystals was characterized by LEED to be consistent with that of the bulk structure. Our data suggest that Bi2CaSr2Cu2O8 single crystals are very stable in the ultrahigh vacuu. No change of XPS spectra with temperature was observed. We have also studied the electronic structure of Bi2Sr2CuO6, which has a lower superconducting transition temperature Tc. Comparing the electronic structure of the two Bi-Ca-Sr-Cu-O superconductors, an important difference in the density of states near EF was observed which seems to be related to the difference in Tc.

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

PubMed

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.

Thumb rule of visual angle: a new confirmation.

PubMed

Groot, C; Ortega, F; Beltran, F S

1994-02-01

The classical thumb rule of visual angle was reexamined. Hence, the visual angle was measured as a function of a thumb's width and the distance between eye and thumb. The measurement of a thumb's width when held at arm's length was taken on 67 second-year students of psychology. The visual angle was about 2 degrees as R. P. O'Shea confirmed in 1991. Also, we confirmed a linear relationship between the size of a thumb's width at arm's length and the visual angle.

A XPS Study of the Passivity of Stainless Steels Influenced by Sulfate-Reducing Bacteria.

NASA Astrophysics Data System (ADS)

Chen, Guocun

The influence of sulfate-reducing bacteria (SRB) on the passivity of type 304 and 317L stainless steels (SS) was investigated by x-ray photoelectron spectroscopy (XPS), microbiological and electrochemical techniques. Samples were exposed to SRB, and then the resultant surfaces were analyzed by XPS, and the corrosion resistance by potentiodynamic polarization in deaerated 0.1 M HCl. To further understand their passivity, the SRB-exposed samples were analyzed by XPS after potentiostatic polarization at a passive potential in the hydrochloric solution. The characterization was performed under two surface conditions: unrinsed and rinsed by deaerated alcohol and deionized water. Comparisons were made with control samples immersed in uninoculated medium. SRB caused a severe loss of the passivity of 304 SS through sulfide formation and possible additional activation to form hexavalent chromium. The sulfides included FeS, FeS_2, Cr_2S _3, NiS and possibly Fe_ {rm 1-x}S. The interaction took place nonuniformly, resulting in undercutting of the passive film and preferential hydration of inner surface layers. The bacterial activation of the Cr^{6+ }^ecies was magnified by subsequent potentiostatic polarization. In contrast, 317L SS exhibited a limited passivity. The sulfides were formed mainly in the outer layers. Although Cr^{6+}^ecies were observed after the exposure, they were dissolved upon polarization. Since 317L SS has a higher Mo content, its higher passivity was ascribed to Mo existing as molybdate on the surface and Mo^{5+} species in the biofilm. Consequently, the interaction of SRB with Mo was studied. It was observed that molybdate could be retained on the surfaces of Mo coupons by corrosion products. In the presence of SRB, however, a considerable portion of the molybdate interacted with intermediate sulfur -containing proteins, forming Mo(V)-S complexes and reducing bacterial growth and sulfate reduction. The limited insolubility of the Mo(V)-S complexes in 0

A Multicenter Randomized Noninferiority Trial Comparing GreenLight-XPS Laser Vaporization of the Prostate and Transurethral Resection of the Prostate for the Treatment of Benign Prostatic Obstruction: Two-yr Outcomes of the GOLIATH Study.

PubMed

Thomas, James A; Tubaro, Andrea; Barber, Neil; d'Ancona, Frank; Muir, Gordon; Witzsch, Ulrich; Grimm, Marc-Oliver; Benejam, Joan; Stolzenburg, Jens-Uwe; Riddick, Antony; Pahernik, Sascha; Roelink, Herman; Ameye, Filip; Saussine, Christian; Bruyère, Franck; Loidl, Wolfgang; Larner, Tim; Gogoi, Nirjan-Kumar; Hindley, Richard; Muschter, Rolf; Thorpe, Andrew; Shrotri, Nitin; Graham, Stuart; Hamann, Moritz; Miller, Kurt; Schostak, Martin; Capitán, Carlos; Knispel, Helmut; Bachmann, Alexander

2016-01-01

The GOLIATH study is a 2-yr trial comparing transurethral resection of prostate (TURP) to photoselective vaporization with the GreenLight XPS Laser System (GL-XPS) for the treatment of benign prostatic obstruction (BPO). Noninferiority of GL-XPS to TURP was demonstrated based on a 6-mo follow-up from the study. To determine whether treatment effects observed at 6 mo between GL-XPS and TURP was maintained at the 2-yr follow-up. Prospective randomized controlled trial at 29 centers in nine European countries involving 281 patients with BPO. Photoselective vaporization using the 180-W GreenLight GL-XPS or conventional (monopolar or bipolar) TURP. The primary outcome was the International Prostate Symptom Score for which a margin of three was used to evaluate the noninferiority of GL-XPS. Secondary outcomes included Qmax, prostate volume, prostate specific antigen, Overactive Bladder Questionnaire Short Form, International Consultation on Incontinence Questionnaire Short Form, occurrence of surgical retreatment, and freedom from complications. One hundred and thirty-six patients were treated using GL-XPS and 133 using TURP. Noninferiority of GL-XPS on International Prostate Symptom Score, Qmax, and freedom from complications was demonstrated at 6-mo and was sustained at 2-yr. The proportion of patients complication-free through 24-mo was 83.6% GL-XPS versus 78.9% TURP. Reductions in prostate volume and prostate specific antigen were similar in both arms and sustained over the course of the trial. Compared with the 1(st) yr of the study, very few adverse events or retreatments were reported in either arm. Treatment differences in the Overactive Bladder Questionnaire Short Form observed at 12-mo were not statistically significant at 24-mo. A limitation was that patients and treating physicians were not blinded to the therapy. Twenty-four-mo follow-up data demonstrated that GL-XPS provides a durable surgical option for the treatment of BPO that exhibits efficacy and

XPS Investigation on Changes in UO 2 Speciation following Exposure to Humidity

DOE PAGES

Donald, Scott B.; Davisson, M. Lee; Nelson, Art J.

2016-04-27

High purity UO 2powder samples were subjected to accelerated aging under controlled conditions with relative humidity ranging from 34% to 98%. Characterization of the chemical speciation of the products was accomplished using X-ray photoelectron spectroscopy (XPS). A shift to higher uranium oxidation states was found to be directly correlated to increased relative humidity exposure. In addition, the relative abundance of O 2-, OH -, and H 2O was found to vary with exposure time. Therefore, it is expected that uranium oxide materials exposed to high relative humidity conditions during processing and storage would display a similar increase in average uraniummore » valence.« less

Using Atmospheric (137)Cs Measurements and Hysplit to Confirm Chernobyl as a Source of (137)Cs in Europe

DTIC Science & Technology

2001-10-01

USING ATMOSPHERIC 137CS MEASUREMENTS AND HYSPLIT TO CONFIRM CHERNOBYL AS A SOURCE OF 137CS IN EUROPE Erik L. Swanberg1 and Steven G. Hoffert2...Veridian Systems1, Autometric2 Sponsored by Defense Threat Reduction Agency Contract No. DTRA01-99-C-0031 ABSTRACT The Chernobyl ...this 137Cs is the ground contaminated by the Chernobyl accident. The PIDC routinely uses HYSPLIT (HYbrid Single-Particle Lagrangian Integrated

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

NASA Astrophysics Data System (ADS)

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

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

PubMed

Zhu, Xiangdong; Yang, Shijun; Wang, Liang; Liu, Yuchen; Qian, Feng; Yao, Wenqing; Zhang, Shicheng; Chen, Jianmin

2016-04-01

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 NH3 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 NH3 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Colloidal diatomite, radionickel, and humic substance interaction: a combined batch, XPS, and EXAFS investigation.

PubMed

Sheng, Guodong; Shen, Runpu; Dong, Huaping; Li, Yimin

2013-06-01

This work determined the influence of humic acid (HA) and fulvic acid (FA) on the interaction mechanism and microstructure of Ni(II) onto diatomite by using batch experiments, X-ray photoelectron spectroscopy (XPS), and extended X-ray absorption fine structure (EXAFS) methods. Macroscopic and spectroscopic experiments have been combined to see the evolution of the interaction mechanism and microstructure of Ni(II) in the presence of HA/FA as compared with that in the absence of HA/FA. The results indicated that the interaction of Ni(II) with diatomite presents the expected solution pH edge at 7.0, which is modified by addition of HA/FA. In the presence of HA/FA, the interaction of Ni(II) with diatomite increased below solution pH 7.0, while Ni(II) interaction decreased above solution pH 7.0. XPS analysis suggested that the enrichment of Ni(II) onto diatomite may be due to the formation of (≡SO)2Ni. EXAFS results showed that binary surface complexes and ternary surface complexes of Ni(II) can be simultaneously formed in the presence of HA/FA, whereas only binary surface complexes of Ni(II) are formed in the absence of HA/FA, which contribute to the enhanced Ni(II) uptake at low pH values. The results observed in this work are important for the evaluation of Ni(II) and related radionuclide physicochemical behavior in the natural soil and water environment.

Surface Propensity of Atmospherically Relevant Amino Acids Studied by XPS.

PubMed

Mocellin, Alexandra; Gomes, Anderson Herbert de Abreu; Araújo, Oscar Cardoso; de Brito, Arnaldo Naves; Björneholm, Olle

2017-04-27

Amino acids constitute an important fraction of the water-soluble organic nitrogen (WSON) compounds in aerosols and are involved in many processes in the atmosphere. In this work, we applied X-ray photoelectron spectroscopy (XPS) to study aqueous solutions of four amino acids, glycine, alanine, valine, and methionine, in their zwitterionic forms. We found that amino acids with hydrophilic side chains and smaller size, GLY and ALA, tend to stay in the bulk of the liquid, while the hydrophobic and bigger amino acids, VAL and MET, are found to concentrate more on the surface. We found experimental evidence that the amino acids have preferential orientation relative to the surface, with the hydrophobic side chain being closer to the surface than the hydrophilic carboxylate group. The observed amino acid surface propensity has implications in atmospheric science as the surface interactions play a central role in cloud droplet formation, and they should be considered in climate models.

Space Time Theories Confirmed

NASA Image and Video Library

2011-05-04

Rex Geveden, President of Teledyne Brown Engineering, makes a point during a press conference, Wednesday, May 4, 2011, to discuss NASA's Gravity Probe B (GP-B) mission which has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test at NASA Headquarters in Washington. The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates. Photo Credit: (NASA/Paul E. Alers)

Observation of GaSe-SnO2 Heterostructure by XPS and AES

NASA Astrophysics Data System (ADS)

Tatsuyama, Chiei; Ichimura, Shoji; Iwakuro, Hiroaki

1982-01-01

The depth profile of the elemental composition of the GaSe-SnO2 heterostructure has been studied by XPS and AES. The SnO2 layer was prepared by spraying a solution of SnCl4 and SbCl3 in ethyl alcohol on to the the cleaved surface of GaSe heated to ˜400°C in air. After the solution had been sprayed on for about 5 secs., an SnO2 layer of thickness ˜460 Å formed, and a Ga2O3 layer of thickness ˜120 Å formed under the SnO2 layer. The Ga2O3 layer is a likely origin of the high-resistivity layer observed in the GaSe-SnO2 heterostructure.

In vivo characterization of magnesium alloy biodegradation using electrochemical H2 monitoring, ICP-MS, and XPS.

PubMed

Zhao, Daoli; Wang, Tingting; Nahan, Keaton; Guo, Xuefei; Zhang, Zhanping; Dong, Zhongyun; Chen, Shuna; Chou, Da-Tren; Hong, Daeho; Kumta, Prashant N; Heineman, William R

2017-03-01

The effect of widely different corrosion rates of Mg alloys on four parameters of interest for in vivo characterization was evaluated: (1) the effectiveness of transdermal H 2 measurements with an electrochemical sensor for noninvasively monitoring biodegradation compared to the standard techniques of in vivo X-ray imaging and weight loss measurement of explanted samples, (2) the chemical compositions of the corrosion layers of the explanted samples by XPS, (3) the effect on animal organs by histology, and (4) the accumulation of corrosion by-products in multiple organs by ICP-MS. The in vivo biodegradation of three magnesium alloys chosen for their widely varying corrosion rates - ZJ41 (fast), WKX41 (intermediate) and AZ31 (slow) - were evaluated in a subcutaneous implant mouse model. Measuring H 2 with an electrochemical H 2 sensor is a simple and effective method to monitor the biodegradation process in vivo by sensing H 2 transdermally above magnesium alloys implanted subcutaneously in mice. The correlation of H 2 levels and biodegradation rate measured by weight loss shows that this non-invasive method is fast, reliable and accurate. Analysis of the insoluble biodegradation products on the explanted alloys by XPS showed all of them to consist primarily of Mg(OH) 2 , MgO, MgCO 3 and Mg 3 (PO 4 ) 2 with ZJ41 also having ZnO. The accumulation of magnesium and zinc were measured in 9 different organs by ICP-MS. Histological and ICP-MS studies reveal that there is no significant accumulation of magnesium in these organs for all three alloys; however, zinc accumulation in intestine, kidney and lung for the faster biodegrading alloy ZJ41 was observed. Although zinc accumulates in these three organs, no toxicity response was observed in the histological study. ICP-MS also shows higher levels of magnesium and zinc in the skull than in the other organs. Biodegradable devices based on magnesium and its alloys are promising because they gradually dissolve and thereby

Characterization of pulsed laser deposition grown V2O3 converted VO2

NASA Astrophysics Data System (ADS)

Majid, Suhail; Shukla, D. K.; Rahman, F.; Gautam, Kamini; Sathe, V. G.; Choudhary, R. J.; Phase, D. M.

2016-10-01

Controllable tuning of Metal-insulator transition in VxOy thin film has been a field of extensive research. However controlled synthesis of desired Vanadium oxide phase is a challenging task. We have successfully achieved VO2 phase on Silicon substrate after post deposition annealing treatment to the PLD grown as deposited V2O3 thin films. The annealed thin film was characterized by x-ray diffraction (XRD), resistivity, Raman spectroscopy, X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) measurements. XRD confirms the crystalline nature and growth of VO2 phase in thin film. The characteristic MIT was observed from resistivity measurements and transition temperature appeared at lower value around 336 K, compared to bulk VO2. The structural transition accompanied with MIT from lower temperature monoclinic phase to higher temperature Rutile phase became evident from temperature dependent Raman measurements. Chemical state of vanadium was examined using XAS and XPS measurements which confirm the presence of +4 oxidation state of vanadium in thin film.

Composition measurement of epitaxial Sc x Ga1-x N films

NASA Astrophysics Data System (ADS)

Tsui, H. C. L.; Goff, L. E.; Barradas, N. P.; Alves, E.; Pereira, S.; Palgrave, R. G.; Davies, R. J.; Beere, H. E.; Farrer, I.; Ritchie, D. A.; Moram, M. A.

2016-06-01

Four different methods for measuring the compositions of epitaxial Sc x Ga1-x N films were assessed and compared to determine which was the most reliable and accurate. The compositions of epitaxial Sc x Ga1-x N films with 0 ≤ x ≤ 0.26 were measured directly using Rutherford backscattering (RBS) and x-ray photoelectron spectroscopy (XPS), and indirectly using c lattice parameter measurements from x-ray diffraction and c/a ratio measurements from electron diffraction patterns. RBS measurements were taken as a standard reference. XPS was found to underestimate the Sc content, whereas c lattice parameter and c/a ratio were not reliable for composition determination due to the unknown degree of strain relaxation in the film. However, the Sc flux used during growth was found to relate linearly with x and could be used to estimate the Sc content.

Space Time Theories Confirmed

NASA Image and Video Library

2011-05-04

Clifford Will, Professor of Physics at Washington University in St. Louis, makes a point during a press conference, Wednesday, May 4, 2011, to discuss NASA's Gravity Probe B (GP-B) mission which has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test at NASA Headquarters in Washington. The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates. Photo Credit: (NASA/Paul E. Alers)

Space Time Theories Confirmed

NASA Image and Video Library

2011-05-04

Clifford Will, Professor of Physics at Washington University in St. Louis, foreground, answers questions during a press conference, Wednesday, May 4, 2011, to discuss NASA's Gravity Probe B (GP-B) mission which has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test at NASA Headquarters in Washington. The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates. Photo Credit: (NASA/Paul E. Alers)

Space Time Theories Confirmed

NASA Image and Video Library

2011-05-04

Francis Everitt, Principal Investigator for the Gravity Probe B Mission at Stanford University, second from left, makes a point during a press conference, Wednesday, May 4, 2011, to discuss NASA's Gravity Probe B (GP-B) mission which has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test at NASA Headquarters in Washington. The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates. Photo Credit: (NASA/Paul E. Alers)

Space Time Theories Confirmed

NASA Image and Video Library

2011-05-04

Francis Everitt, Principal Investigator for the Gravity Probe B Mission at Stanford University, makes a point during a press conference, Wednesday, May 4, 2011, to discuss NASA's Gravity Probe B (GP-B) mission which has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test at NASA Headquarters in Washington. The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates. Photo Credit: (NASA/Paul E. Alers)

Space Time Theories Confirmed

NASA Image and Video Library

2011-05-04

Colleen Hartman, Senior Advisor at NASA Headquarters and Research Professor at George Washington University, makes a point during a press conference, Wednesday, May 4, 2011, to discuss NASA's Gravity Probe B (GP-B) mission which has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test at NASA Headquarters in Washington. The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates. Photo Credit: (NASA/Paul E. Alers)

Initial stages of oxide formation on the Zr surface at low oxygen pressure: An in situ FIM and XPS study

PubMed Central

Bespalov, I.; Datler, M.; Buhr, S.; Drachsel, W.; Rupprechter, G.; Suchorski, Y.

2015-01-01

An improved methodology of the Zr specimen preparation was developed which allows fabrication of stable Zr nanotips suitable for FIM and AP applications. Initial oxidation of the Zr surface was studied on a Zr nanotip by FIM and on a polycrystalline Zr foil by XPS, both at low oxygen pressure (10−8–10−7 mbar). The XPS data reveal that in a first, fast stage of oxidation, a Zr suboxide interlayer is formed which contains three suboxide components (Zr+1, Zr+2 and Zr+3) and is located between the Zr surface and a stoichiometric ZrO2 overlayer that grows in a second, slow oxidation stage. The sole suboxide layer has been observed for the first time at very early states of the oxidation (oxygen exposure ≤4 L). The Ne+ FIM observations are in accord with a two stage process of Zr oxide formation. PMID:25766998

Reorientation-effect measurement of the first 2+ state in 12C: Confirmation of oblate deformation

NASA Astrophysics Data System (ADS)

Kumar Raju, M.; Orce, J. N.; Navrátil, P.; Ball, G. C.; Drake, T. E.; Triambak, S.; Hackman, G.; Pearson, C. J.; Abrahams, K. J.; Akakpo, E. H.; Al Falou, H.; Churchman, R.; Cross, D. S.; Djongolov, M. K.; Erasmus, N.; Finlay, P.; Garnsworthy, A. B.; Garrett, P. E.; Jenkins, D. G.; Kshetri, R.; Leach, K. G.; Masango, S.; Mavela, D. L.; Mehl, C. V.; Mokgolobotho, M. J.; Ngwetsheni, C.; O'Neill, G. G.; Rand, E. T.; Sjue, S. K. L.; Sumithrarachchi, C. S.; Svensson, C. E.; Tardiff, E. R.; Williams, S. J.; Wong, J.

2018-02-01

A Coulomb-excitation reorientation-effect measurement using the TIGRESS γ-ray spectrometer at the TRIUMF/ISAC II facility has permitted the determination of the 〈 21+ ‖ E 2 ˆ ‖21+ 〉 diagonal matrix element in 12C from particle-γ coincidence data and state-of-the-art no-core shell model calculations of the nuclear polarizability. The nuclear polarizability for the ground and first-excited (21+) states in 12C have been calculated using chiral NN N4LO500 and NN+3NF350 interactions, which show convergence and agreement with photo-absorption cross-section data. Predictions show a change in the nuclear polarizability with a substantial increase between the ground state and first excited 21+ state at 4.439 MeV. The polarizability of the 21+ state is introduced into the current and previous Coulomb-excitation reorientation-effect analyses of 12C. Spectroscopic quadrupole moments of QS (21+) = + 0.053 (44) eb and QS (21+) = + 0.08 (3) eb are determined, respectively, yielding a weighted average of QS (21+) = + 0.071 (25) eb, in agreement with recent ab initio calculations. The present measurement confirms that the 21+ state of 12C is oblate and emphasizes the important role played by the nuclear polarizability in Coulomb-excitation studies of light nuclei.

TWO STARS TWO WAYS: CONFIRMING A MICROLENSING BINARY LENS SOLUTION WITH A SPECTROSCOPIC MEASUREMENT OF THE ORBIT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yee, Jennifer C.; Johnson, John Asher; Eastman, Jason

Light curves of microlensing events involving stellar binaries and planetary systems can provide information about the orbital elements of the system due to orbital modulations of the caustic structure. Accurately measuring the orbit in either the stellar or planetary case requires detailed modeling of subtle deviations in the light curve. At the same time, the natural, Cartesian parameterization of a microlensing binary is partially degenerate with the microlens parallax. Hence, it is desirable to perform independent tests of the predictions of microlens orbit models using radial velocity (RV) time series of the lens binary system. To this end, we presentmore » 3.5 years of RV monitoring of the binary lens system OGLE-2009-BLG-020 L, for which Skowron et al. constrained all internal parameters of the 200–700 day orbit. Our RV measurements reveal an orbit that is consistent with the predictions of the microlens light curve analysis, thereby providing the first confirmation of orbital elements inferred from microlensing events.« less

Compositional and surface characterization of HULIS by UV-Vis, FTIR, NMR and XPS: Wintertime study in Northern India

NASA Astrophysics Data System (ADS)

Kumar, Varun; Goel, Anubha; Rajput, Prashant

2017-09-01

This study (first attempt) characterizes HULIS (Humic Like Substances) in wintertime aerosols (n = 12 during day and nighttime each) from Indo-Gangetic Plain (IGP, at Kanpur) by using various state-of-the art techniques such as UV-VIS, FTIR, 1H NMR and XPS. Based on UV-Vis analysis the absorption coefficient at 365 nm (babs-365) of HULIS was found to average at 13.6 and 28.8 Mm-1 during day and nighttime, respectively. Relatively high babs-365 of HULIS during the nighttime is attributed to influence of fog-processing. However, the power fit of UV-Vis spectrum provided near similar AAE (absorption Angstrom exponent) value of HULIS centering at 4.9 ± 1.4 and 5.1 ± 1.3 during daytime and nighttime, respectively. FTIR spectra and its double derivative revealed the presence of various functional groups viz. alcohols, ketones aldehydes, carboxylic acids as well as unsaturated and saturated carbon bonds. 1H NMR spectroscopy was applied to quantify relative percentage of various types of hydrogen atoms contained in HULIS, whereas XPS technique provided information on surface composition and oxidation states of various elements present. A significantly high abundance of H‒C‒O group has been observed in HULIS (based on 1H NMR); 41.4± 2.7% and 30.9± 2.4% in day and nighttime, respectively. However, aromatic protons (Ar-H) were higher in nighttime samples (19.3± 1.8%) as compared to that in daytime samples (7.5 ± 1.9). XPS studies revealed presence of various species on the surface of HULIS samples. Carbon existed in 7 different chemical states while total nitrogen and sulfur exhibited 3 and 2 different oxidation states (respectively) on the surface of HULIS. This study reports structural information and absorption properties of HULIS which has implications to their role as cloud condensation nuclei and atmospheric direct radiative forcing.

Effects of delayed-release dimethyl fumarate on MRI measures in the phase 3 CONFIRM study.

PubMed

Miller, David H; Fox, Robert J; Phillips, J Theodore; Hutchinson, Michael; Havrdova, Eva; Kita, Mariko; Wheeler-Kingshott, Claudia A M; Tozer, Daniel J; MacManus, David G; Yousry, Tarek A; Goodsell, Mary; Yang, Minhua; Zhang, Ray; Viglietta, Vissia; Dawson, Katherine T

2015-03-17

To evaluate the effects of oral delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) on MRI lesion activity and load, atrophy, and magnetization transfer ratio (MTR) measures from the Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis (CONFIRM) study. CONFIRM was a 2-year, placebo-controlled study of the efficacy and safety of DMF 240 mg twice (BID) or 3 times daily (TID) in 1,417 patients with relapsing-remitting multiple sclerosis (RRMS); subcutaneous glatiramer acetate 20 mg once daily was included as an active reference comparator. The number and volume of T2-hyperintense, T1-hypointense, and gadolinium-enhancing (Gd+) lesions, as well as whole brain volume and MTR, were assessed in 681 patients (MRI cohort). DMF BID and TID produced significant and consistent reductions vs placebo in the number of new or enlarging T2-hyperintense lesions and new nonenhancing T1-hypointense lesions after 1 and 2 years of treatment and in the number of Gd+ lesions at week 24, year 1, and year 2. Lesion volumes were also significantly reduced. Reductions in brain atrophy and MTR changes with DMF relative to placebo did not reach statistical significance. The robust effects on MRI active lesion counts and total lesion volume in patients with RRMS demonstrate the ability of DMF to exert beneficial effects on inflammatory lesion activity in multiple sclerosis, and support DMF therapy as a valuable new treatment option in RRMS. This study provides Class I evidence of reduction in brain lesion number and volume, as assessed by MRI, over 2 years of delayed-release DMF treatment. © 2015 American Academy of Neurology.

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

NASA Astrophysics Data System (ADS)

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.

Effects of M=Si, Ga and Al for Co substitution on the electronic properties of RCo4M as probed by XPS

NASA Astrophysics Data System (ADS)

Laslo, A.; Dudric, R.; Neumann, M.; Isnard, O.; Coldea, M.; Pop, V.

2014-12-01

The electronic properties of RCo5-xMx (R=Er, Sm, Tm; M=Si, Ga, Al; x=0 and 1) compounds were investigated by X-ray photoelectron spectroscopy (XPS). The study was focused on the Co 3s exchange splitting, the valence bands and chemical shifts of the elements from the analyzed compounds. The Co 2p3/2 core-level chemical shifts were described by means of the Auger parameters and Wagner plot. The hybridization between the R 5d6s and M 3sp and 4sp states and Co 3d states leads to a partial filling of the Co 3d band and to a decrease of the Co magnetic moments in comparison with the value in pure Co metal, in good agreement with the magnetic measurements.

Precision Measurement of The Most Distant Spectroscopically Confirmed

Science.gov Websites

Supernova SAO/NASA ADS Astronomy Abstract Service Title: Precision Measurement of The Most Space Astronomy, 389 UCB, University of Colorado, Boulder, CO 80309, USA), AI(Hamilton College Astronomy, Vanderbilt University, Nashville, TN 37240, USA), AO(E. O. Lawrence Berkeley National Lab, 1

Towards nanometric resolution in multilayer depth profiling: a comparative study of RBS, SIMS, XPS and GDOES.

PubMed

Escobar Galindo, Ramón; Gago, Raul; Duday, David; Palacio, Carlos

2010-04-01

An increasing amount of effort is currently being directed towards the development of new functionalized nanostructured materials (i.e., multilayers and nanocomposites). Using an appropriate combination of composition and microstructure, it is possible to optimize and tailor the final properties of the material to its final application. The analytical characterization of these new complex nanostructures requires high-resolution analytical techniques that are able to provide information about surface and depth composition at the nanometric level. In this work, we comparatively review the state of the art in four different depth-profiling characterization techniques: Rutherford backscattering spectroscopy (RBS), secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and glow discharge optical emission spectroscopy (GDOES). In addition, we predict future trends in these techniques regarding improvements in their depth resolutions. Subnanometric resolution can now be achieved in RBS using magnetic spectrometry systems. In SIMS, the use of rotating sample holders and oxygen flooding during analysis as well as the optimization of floating low-energy ion guns to lower the impact energy of the primary ions improves the depth resolution of the technique. Angle-resolved XPS provides a very powerful and nondestructive technique for obtaining depth profiling and chemical information within the range of a few monolayers. Finally, the application of mathematical tools (deconvolution algorithms and a depth-profiling model), pulsed sources and surface plasma cleaning procedures is expected to greatly improve GDOES depth resolution.

Applications of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) to study interactions of genetically engineered proteins with noble metal films

NASA Astrophysics Data System (ADS)

Suzuki, Noriaki

Genetically engineered proteins for inorganics (GEPIs) belong to a new class of polypeptides that are designed to have specific affinities to inorganic materials. A "gold binding protein (GBP)" was chosen as a model protein for GEPIs to study the molecular origins of binding specificity to gold using Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS). TOF-SIMS, a surface-sensitive analytical instrument with extremely high mass resolutions, provides information on specific amino acid-surface interactions. We used "principal component analysis (PCA)" to analyze the data. We also introduced a new multivariate technique, "hierarchical cluster analysis (HCA)" to organize the data into meaningful structures by measuring a degree of "similarity" and "dissimilarity" of the data. This report discusses a combined use of PCA and HCA to elucidate the binding specificity of GBP to Au. Based on the knowledge gained from TOF-SIMS measurements, we further investigated the nature of the interaction between selected amino acids and noble metal surfaces by using X-ray photoelectron spectroscopy (XPS). We developed a unique capability to introduce water vapor during the adsorption of a single amino acid and applied this method to study the intrinsic nature of sidechain/Au interactions. To further apply this unique research protocol, we characterized another type of GEPI, "quartz binding protein (QBP)," to identify the possible binding sites. This thesis research aims to provide experimental protocols for analyzing short peptide-substrate interface from complex spectroscopic data by using multivariate analysis techniques.

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

PubMed Central

Martinez, Daniel Roberto; Ercole, Cesar E; Lopez, Juan Gabriel; Parker, Justin; Hall, Mary K

2015-01-01

ABSTRACT Introduction: 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. PMID:26200555

XPS and biocompatibility studies of titania film on anodized NiTi shape memory alloy.

PubMed

Chu, C L; Wang, R M; Hu, T; Yin, L H; Pu, Y P; Lin, P H; Dong, Y S; Guo, C; Chung, C Y; Yeung, K W K; Chu, Paul K

2009-01-01

A dense titania film is fabricated in situ on NiTi shape memory alloy (SMA) by anodic oxidation in a Na(2)SO(4) electrolyte. The microstructure of the titania film and its influence on the biocompatibility of NiTi SMA are investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICPMS), hemolysis analysis, and platelet adhesion test. The results indicate that the titania film has a Ni-free zone near the surface and can effectively block the release of harmful Ni ions from the NiTi substrate in simulated body fluids. Moreover, the wettability, hemolysis resistance, and thromboresistance of the NiTi sample are improved by this anodic oxidation method.

Depth profile composition studies of thin film CdS:Cu2S solar cells using XPS and AES

NASA Astrophysics Data System (ADS)

Bhide, V. G.; Salkalachen, S.; Rastogi, A. C.; Rao, C. N. R.; Hegde, M. S.

1981-09-01

Studies of the surface composition and depth profiles of thin film CdS:Cu2S solar cells based on the techniques of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) are reported. Specimens were fabricated by the thermal deposition of polycrystalline CdS films onto silver-backed electrodes predeposited on window glass substrates, followed by texturization in hot HCl and chemical plating in a hot CuCl(I) bath for a few seconds to achieve the topotaxial growth of CuS films. The XPS and AES studies indicate the junction to be fairly diffused in the as-prepared cell, with heat treatment in air at 210 C sharpening the junction, improving the stoichiometry of the Cu2S layer and thus improving cell performance. The top copper sulfide layer is found to contain impurities such as Cd, Cl, O and C, which may be removed by mild Ar(+) ion beam etching. The presence of copper deep in the junction is invariably detected, apparently in the grain boundary region in the form of CuS or Cu(2+) trapped in the lattice. It is also noted that the nominal valence state of copper changes abruptly from Cu(+) to Cu(2+) across the junction.

Interactions of gaseous molecules with X-ray photons and photoelectrons in AP-XPS study of solid surface in gas phase.

PubMed

Tao, Franklin Feng; Nguyen, Luan

2018-04-18

Studies of the surface of a catalyst in the gas phase via photoelectron spectroscopy is an important approach to establish a correlation between the surface of a catalyst under reaction conditions or during catalysis and its corresponding catalytic performance. Unlike the well understood interactions between photoelectrons and the atomic layers of a surface in ultrahigh vacuum (UHV) and the well-developed method of quantitative analysis of a solid surface in UHV, a fundamental understanding of the interactions between X-ray photons and gaseous molecules and between photoelectrons and molecules of the gas phase in ambient pressure X-ray photoelectron spectroscopy (AP-XPS) is lacking. Through well designed experiments, here the impact of the interactions between photoelectrons and gaseous molecules and interactions between X-ray photons and gaseous molecules on the intensity of the collected photoelectrons have been explored. How the changes in photoelectron intensity resulting from these interactions influence measurement of the authentic atomic ratio of element M to A of a solid surface has been discussed herein, and methods to correct the measured nominal atomic ratio of two elements of a solid surface upon travelling through a gas phase to its authentic atomic ratio have been developed.

Layer uniformity in glucose oxidase immobilization on SiO 2 surfaces

NASA Astrophysics Data System (ADS)

Libertino, Sebania; Scandurra, Antonino; Aiello, Venera; Giannazzo, Filippo; Sinatra, Fulvia; Renis, Marcella; Fichera, Manuela

2007-09-01

The goal of this work was the characterization, step by step, of the enzyme glucose oxidase (GOx) immobilization on silicon oxide surfaces, mainly by means of X-Ray photoelectron spectroscopy (XPS). The immobilization protocol consists of four steps: oxide activation, silanization, linker molecule deposition and GOx immobilization. The linker molecule, glutaraldehyde (GA) in this study, must be able to form a uniform layer on the sample surface in order to maximize the sites available for enzyme bonding and achieve the best enzyme deposition. Using a thin SiO 2 layer grown on Si wafers and following the XPS Si2p signal of the Si substrate during the immobilization steps, we demonstrated both the glutaraldehyde layer uniformity and the possibility to use XPS to monitor thin layer uniformity. In fact, the XPS substrate signal, not shielded by the oxide, is suppressed only when a uniform layer is deposited. The enzyme correct immobilization was monitored using the XPS C1s and N1s signals. Atomic force microscopy (AFM) measurements carried out on the same samples confirmed the results.

[XPS analysis of beads formed by fuse breaking of electric copper wire].

PubMed

Wu, Ying; Meng, Qing-Shan; Wang, Xin-Ming; Gao, Wei; Di, Man

2010-05-01

The in-depth composition of beads formed by fuse breaking of the electric copper wire in different circumstances was studied by XPS with Ar+ ion sputtering. In addition, the measured Auger spectra and the calculated Auger parameters were compared for differentiation of the substances of Cu and Cu2O. Corresponding to the sputtering depth, the molten product on a bead induced directly by fuse breaking of the copper wire without cover may be distinguished as three portions: surface layer with a drastic decrease in carbon content; intermediate layer with a gentle change in oxygen content and gradually diminished carbon peak, and consisting of Cu2O; transition layer without Cu2O and with a rapid decrease in oxygen content. While the molten product on a bead formed by fuse breaking of the copper wire after its insulating cover had been burned out may be distinguished as two portions: surface layer with carbon content decreasing quickly; subsurface layer without Cu2O and with carbon and oxygen content decreasing gradually. Thus, it can be seen that there was an obvious interface between the layered surface product and the substrate for the first type of bead, while as to the second type of bead there was no interface. As a result, the presence of Cu2O and the quantitative results can be used to identify the molten product on a bead induced directly by fuse breaking of the copper wire without cover and the molten product on a bead formed by fuse breaking of the cupper wire after its insulating cover had been burned out, as a complementary technique for the judgments of fire cause.

Surface analysis of glass fibres using XPS and AFM: case study of glass fibres recovered from the glass fibre reinforced polymer using chemical recycling

NASA Astrophysics Data System (ADS)

Nzioka, A. M.; Kim, Y. J.

2018-01-01

In this study, we present the results of an experimental study of the use of the X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) to characterise the coatings of the recovered E - glass fibres. The recovered E - glass fibres were obtained using chemical recycling process coupled with ultrasound cavitation. The objective of this study was to analyse the impact of chemical recycling and the ultrasound cavitation process on the sizing properties of the recovered fibres. We obtained the recovered fibres and sized using 1 wt% 3 - aminopropyltriethoxysilane (APS). Part of the sized fibres was washed with acetone and analysed all the sample fibres using AFM and XPS. Results showed the different composition of sizing after extraction using acetone. We compared the results of this study with that of virgin clean glass fibres.

In-situ XPS analysis of oxidized and reduced plasma deposited ruthenium-based thin catalytic films

NASA Astrophysics Data System (ADS)

Balcerzak, Jacek; Redzynia, Wiktor; Tyczkowski, Jacek

2017-12-01

A novel in-situ study of the surface molecular structure of catalytically active ruthenium-based films subjected to the oxidation (in oxygen) and reduction (in hydrogen) was performed in a Cat-Cell reactor combined with a XPS spectrometer. The films were produced by the plasma deposition method (PEMOCVD). It was found that the films contained ruthenium at different oxidation states: metallic (Ru0), RuO2 (Ru+4), and other RuOx (Ru+x), of which content could be changed by the oxidation or reduction, depending on the process temperature. These results allow to predict the behavior of the Ru-based catalysts in different redox environments.

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

NASA Astrophysics Data System (ADS)

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.

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

DOE PAGES

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

2016-12-31

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 Å 2 and 11.6×11.6 Å 2, 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 ofmore » 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. In conclusion, 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).« less

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

NASA Astrophysics Data System (ADS)

Greunz, Theresia; Duchaczek, Hubert; Sagl, Raffaela; Duchoslav, Jiri; Steinberger, Roland; Strauß, Bernhard; Stifter, David

2017-02-01

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.

XPS Spectra Analysis of Ti2+, Ti3+ Ions and Dye Photodegradation Evaluation of Titania-Silica Mixed Oxide Nanoparticles

NASA Astrophysics Data System (ADS)

Chinh, Vu Duc; Broggi, Alessandra; Di Palma, Luca; Scarsella, Marco; Speranza, Giorgio; Vilardi, Giorgio; Thang, Pham Nam

2018-04-01

TiO2-SiO2 mixed oxides have been prepared by the sol-gel technique from tetrabutyl orthotitanate and tetraethyl orthosilicate. The prepared materials were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, nitrogen physisorption, Fourier-transform infrared spectroscopy (FT-IR) and x-ray photoelectron spectroscopy (XPS). The results indicate that the TiO2-SiO2 mixed oxides have a large surface area and a nanoscale size. FT-IR spectra show that Ti atoms are bonded to silica by oxygen bridging atoms in Ti-O-Si bonds. The titanium valence states in TiO2-SiO2 mixed oxides were investigated by XPS, and their spectra report the presence of Ti2+ and Ti3+ cations for high silica concentration, suggesting the formation of oxygen vacancies. The photocatalytic activity of the prepared materials has been evaluated for the photodegradation of methylene blue (MB). The mixed oxides were activated by means of a UV light source, and the concentration of MB was monitored by UV-Vis spectroscopy. The synthesized TiO2-SiO2 shows significantly higher MB removal efficiency in comparison with that of the commercial TiO2 Degussa, P25.

New insights into micro/nanoscale combined probes (nanoAuger, μXPS) to characterize Ag/Au@SiO2 core-shell assemblies

NASA Astrophysics Data System (ADS)

Ledeuil, J. B.; Uhart, A.; Soulé, S.; Allouche, J.; Dupin, J. C.; Martinez, H.

2014-09-01

This work has examined the elemental distribution and local morphology at the nanoscale of core@shell Ag/Au@SiO2 particles. The characterization of such complex metal/insulator materials becomes more efficient when using an initial cross-section method of preparation of the core@shell nanoparticles (ion milling cross polisher). The originality of this route of preparation allows one to obtain undamaged, well-defined and planar layers of cross-cut nano-objects. Once combined with high-resolution techniques of characterization (XPS, Auger and SEM), the process appears as a powerful way to minimize charging effects and enhance the outcoming electron signal (potentially affected by the topography of the material) during analysis. SEM experiments have unambiguously revealed the hollow-morphology of the metal core, while Auger spectroscopy observations showed chemical heterogeneity within the particles (as silver and gold are randomly found in the core ring). To our knowledge, this is the first time that Auger nano probe spectroscopy has been used and successfully optimized for the study of some complex metal/inorganic interfaces at such a high degree of resolution (~12 nm). Complementarily, XPS Au 4f and Ag 3d peaks were finally detected attesting the possibility of access to the whole chemistry of such nanostructured assemblies.This work has examined the elemental distribution and local morphology at the nanoscale of core@shell Ag/Au@SiO2 particles. The characterization of such complex metal/insulator materials becomes more efficient when using an initial cross-section method of preparation of the core@shell nanoparticles (ion milling cross polisher). The originality of this route of preparation allows one to obtain undamaged, well-defined and planar layers of cross-cut nano-objects. Once combined with high-resolution techniques of characterization (XPS, Auger and SEM), the process appears as a powerful way to minimize charging effects and enhance the outcoming

Facile Synthesis and Characterization of ZrO₂ Nanoparticles via Modified Co-Precipitation Method.

PubMed

Ramachandran, M; Subadevi, R; Liu, Wei-Ren; Sivakumar, M

2018-01-01

The crystalline Zirconium oxide (ZrO2) nano particles were synthesized using optimized content of Zirconium nitrate (Zr(NO3)2·3H2O) with varying KOH concentration (0.5, 1 and 1.5 M) by co-precipitation method. The thermal history of the precursor was carefully analyzed through Thermogravimetric (TG/DTA) measurement. The as prepared samples were characterized to ensure structural, functional, morphological, compositional, chemical composition and band gap by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Laser Raman, scanning electron microscopy (SEM), High resolution Transverse Electron Microscopy (HR-TEM), X-ray photo electron spectroscopy (XPS), EDX, Photo luminescence spectroscopy (PL). The monoclinic structure with space group P21/c has been confirmed from XRD (JCPDS 89-9066). The Zr-O stretching vibration and Zr-O2-Zr bending vibrations were confirmed through FTIR analysis. The well dispersed particles with spherical morphology were confirmed through SEM and TEM analysis. The oxidation states of Zr, O and C were confirmed through XPS analysis. The oxygen vacancies and band gap of the particles were investigated through PL analysis.

In situ formation of the active sites in Pd-Au bimetallic nanocatalysts for CO oxidation: NAP (near ambient pressure) XPS and MS study.

PubMed

Bukhtiyarov, A V; Prosvirin, I P; Saraev, A A; Klyushin, A Yu; Knop-Gericke, A; Bukhtiyarov, V I

2018-06-07

Model bimetallic Pd-Au/HOPG catalysts have been investigated in the CO oxidation reaction using a combination of NAP XPS and MS techniques. The samples have shown catalytic activity at temperatures above 150 °C. The redistribution of Au and Pd on the surface depending on the reaction conditions has been demonstrated using NAP XPS. The Pd enrichment of the bimetallic particles' surface under reaction gas mixture has been shown. Apparently, CO adsorption induces Pd segregation on the surface. Heating the sample under reaction conditions above 150 °C decomposes the Pd-CO state due to CO desorption and reaction and simultaneous Pd-Au alloy formation on the surface takes place. Cooling back down to RT results in reversible Pd segregation due to Pd-CO formation and the sample becomes inactive. It has been shown that in situ studies are necessary for investigation of the active sites in Pd-Au bimetallic systems.

Surface Functionalization of Diamond Films by Photoreaction of Elemental Sulfur and Their Surface Properties

NASA Astrophysics Data System (ADS)

Nakamura, Takako; Ohana, Tsuguyori

2012-08-01

A useful method for direct sulfurization of diamond film surfaces by photoreaction of elemental sulfur was developed. The introduction of thiol groups onto the diamond films was confirmed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and scanning electron microscopy (SEM) analyses. The sulfur-modified diamond films attached to gold nanoparticles by self-assembly. The degrees of thiol group introduction and gold attachment were found to depend on photoirradiation time by monitoring by XPS. The gold-modified diamond film was observed to act as a surface-enhanced Raman scattering substrate for measurement of picric acid.

A New Way to Confirm Planet Candidates

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-05-01

What was the big deal behind the Kepler news conference yesterday? Its not just that the number of confirmed planets found by Kepler has more than doubled (though thats certainly exciting news!). Whats especially interesting is the way in which these new planets were confirmed.Number of planet discoveries by year since 1995, including previous non-Kepler discoveries (blue), previous Kepler discoveries (light blue) and the newly validated Kepler planets (orange). [NASA Ames/W. Stenzel; Princeton University/T. Morton]No Need for Follow-UpBefore Kepler, the way we confirmed planet candidates was with follow-up observations. The candidate could be validated either by directly imaging (which is rare) or obtaining a large number radial-velocity measurements of the wobble of the planets host star due to the planets orbit. But once Kepler started producing planet candidates, these approaches to validation became less feasible. A lot of Kepler candidates are small and orbit faint stars, making follow-up observations difficult or impossible.This problem is what inspired the development of whats known as probabilistic validation, an analysis technique that involves assessing the likelihood that the candidates signal is caused by various false-positive scenarios. Using this technique allows astronomers to estimate the likelihood of a candidate signal being a true planet detection; if that likelihood is high enough, the planet candidate can be confirmed without the need for follow-up observations.A breakdown of the catalog of Kepler Objects of Interest. Just over half had previously been identified as false positives or confirmed as candidates. 1284 are newly validated, and another 455 have FPP of1090%. [Morton et al. 2016]Probabilistic validation has been used in the past to confirm individual planet candidates in Kepler data, but now Timothy Morton (Princeton University) and collaborators have taken this to a new level: they developed the first code thats designed to do fully

In situ NAP-XPS spectroscopy during methane dry reforming on ZrO2/Pt(1 1 1) inverse model catalyst

NASA Astrophysics Data System (ADS)

Rameshan, C.; Li, H.; Anic, K.; Roiaz, M.; Pramhaas, V.; Rameshan, R.; Blume, R.; Hävecker, M.; Knudsen, J.; Knop-Gericke, A.; Rupprechter, G.

2018-07-01

Due to the need of sustainable energy sources, methane dry reforming is a useful reaction for conversion of the greenhouse gases CH4 and CO2 to synthesis gas (CO  +  H2). Syngas is the basis for a wide range of commodity chemicals and can be utilized for fuel production via Fischer–Tropsch synthesis. The current study focuses on spectroscopic investigations of the surface and reaction properties of a ZrO2/Pt inverse model catalyst, i.e. ZrO2 particles (islands) grown on a Pt(1 1 1) single crystal, with emphasis on in situ near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) during MDR reaction. In comparison to technological systems, model catalysts facilitate characterization of the surface (oxidation) state, surface adsorbates, and the role of the metal-support interface. Using XPS and infrared reflection absorption spectroscopy we demonstrated that under reducing conditions (UHV or CH4) the ZrO2 particles transformed to an ultrathin ZrO2 film that started to cover (wet) the Pt surface in an SMSI-like fashion, paralleled by a decrease in surface/interface oxygen. In contrast, (more oxidizing) dry reforming conditions with a 1:1 ratio of CH4 and CO2 were stabilizing the ZrO2 particles on the model catalyst surface (or were even reversing the strong metal support interaction (SMSI) effect), as revealed by in situ XPS. Carbon deposits resulting from CH4 dissociation were easily removed by CO2 or by switching to dry reforming conditions (673–873 K). Thus, at these temperatures the active Pt surface remained free of carbon deposits, also preserving the ZrO2/Pt interface.

Ageing of plasma-mediated coatings with embedded silver nanoparticles on stainless steel: An XPS and ToF-SIMS investigation

NASA Astrophysics Data System (ADS)

Zanna, S.; Saulou, C.; Mercier-Bonin, M.; Despax, B.; Raynaud, P.; Seyeux, A.; Marcus, P.

2010-09-01

Nanocomposite thin films (˜170 nm), composed of silver nanoparticles enclosed in an organosilicon matrix, were deposited onto stainless steel, with the aim of preventing biofilm formation. The film deposition was carried out under cold plasma conditions, combining radiofrequency (RF) glow discharge fed with argon and hexamethyldisiloxane and simultaneous silver sputtering. XPS and ToF-SIMS were used to characterize Ag-organosilicon films in native form and after ageing in saline solution (NaCl 0.15 M), in order to further correlate their lifetime with their anti-fouling properties. Two coatings with significantly different silver contents (7.5% and 20.3%) were tested. Surface analysis confirmed the presence of metallic silver in the pristine coating and revealed significant modifications after immersion in the saline solution. Two different ageing mechanisms were observed, depending on the initial silver concentration in the film. For the sample exhibiting the low silver content (7.5%), the metal amount decreased at the surface in contact with the solution, due to the release of silver from the coating. As a result, after a 2-day exposure, silver nanoparticles located at the extreme surface were entirely released, whereas silver is still present in the inner part of the film. The coating thickness was not modified during ageing. In contrast, for the high silver content film (20.3%), the thickness decreased with immersion time, due to significant silver release and matrix erosion, assigned to a percolation-like effect. However, after 18 days of immersion, the delamination process stopped and a thin strongly bounded layer remained on the stainless steel surface.

Atomistic characterisation of Li+ mobility and conductivity in Li(7-x)PS(6-x)Ix argyrodites from molecular dynamics simulations, solid-state NMR, and impedance spectroscopy.

PubMed

Pecher, Oliver; Kong, Shiao-Tong; Goebel, Thorsten; Nickel, Vera; Weichert, Katja; Reiner, Christof; Deiseroth, Hans-Jörg; Maier, Joachim; Haarmann, Frank; Zahn, Dirk

2010-07-26

The atomistic mechanisms of Li(+) ion mobility/conductivity in Li(7-x)PS(6-x)I(x) argyrodites are explored from both experimental and theoretical viewpoints. Ionic conductivity in the title compound is associated with a solid-solid phase transition, which was characterised by low-temperature differential scanning calorimetry, (7)Li and (127)I NMR investigations, impedance measurements and molecular dynamics simulations. The NMR signals of both isotopes are dominated by anisotropic interactions at low temperatures. A significant narrowing of the NMR signal indicates a motional averaging of the anisotropic interactions above 177+/-2 K. The activation energy to ionic conductivity was assessed from both impedance spectroscopy and molecular dynamics simulations. The latter revealed that a series of interstitial sites become accessible to the Li(+) ions, whilst the remaining ions stay at their respective sites in the argyrodite lattice. The interstitial positions each correspond to the centres of tetrahedra of S/I atoms, and differ only in terms of their common corners, edges, or faces with adjacent PS(4) tetrahedra. From connectivity analyses and free-energy rankings, a specific tetrahedron is identified as the key restriction to ionic conductivity, and is clearly differentiated from local mobility, which follows a different mechanism with much lower activation energy. Interpolation of the lattice parameters as derived from X-ray diffraction experiments indicates a homogeneity range for Li(7-x)PS(6-x)I(x) with 0.97 < or = x < or = 1.00. Within this range, molecular dynamics simulations predict Li(+) conductivity at ambient conditions to vary considerably.

Potassium-doped n-type bilayer graphene

NASA Astrophysics Data System (ADS)

Yamada, Takatoshi; Okigawa, Yuki; Hasegawa, Masataka

2018-01-01

Potassium-doped n-type bilayer graphene was obtained. Chemical vapor deposited bilayer and single layer graphene on copper (Cu) foils were used. After etching of Cu foils, graphene was dipped in potassium hydroxide aqueous solutions to dope potassium. Graphene on silicon oxide was characterized by X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), and Raman spectroscopy. Both XPS and EDX spectra indicated potassium incorporation into the bilayer graphene via intercalation between the graphene sheets. The downward shift of the 2D peak position of bilayer graphene after the potassium hydroxide (KOH) treatment was confirmed in Raman spectra, indicating that the KOH-treated bilayer graphene was doped with electrons. Electrical properties were measured using Hall bar structures. The Dirac points of bilayer graphene were shifted from positive to negative by the KOH treatment, indicating that the KOH-treated bilayer graphene was n-type conduction. For single layer graphene after the KOH treatment, although electron doping was confirmed from Raman spectra, the peak of potassium in the X-ray photoelectron spectroscopy (XPS) spectrum was not detected. The Dirac points of single layer graphene with and without the KOH treatment showed positive.

CONFIRMATION OF HOT JUPITER KEPLER-41b VIA PHASE CURVE ANALYSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quintana, Elisa V.; Rowe, Jason F.; Caldwell, Douglas A.

We present high precision photometry of Kepler-41, a giant planet in a 1.86 day orbit around a G6V star that was recently confirmed through radial velocity measurements. We have developed a new method to confirm giant planets solely from the photometric light curve, and we apply this method herein to Kepler-41 to establish the validity of this technique. We generate a full phase photometric model by including the primary and secondary transits, ellipsoidal variations, Doppler beaming, and reflected/emitted light from the planet. Third light contamination scenarios that can mimic a planetary transit signal are simulated by injecting a full rangemore » of dilution values into the model, and we re-fit each diluted light curve model to the light curve. The resulting constraints on the maximum occultation depth and stellar density combined with stellar evolution models rules out stellar blends and provides a measurement of the planet's mass, size, and temperature. We expect about two dozen Kepler giant planets can be confirmed via this method.« less

Identification of the silver state in the framework of Ag-containing zeolite by XRD, FTIR, photoluminescence, 109Ag NMR, EPR, DR UV-vis, TEM and XPS investigations.

PubMed

Popovych, Nataliia; Kyriienko, Pavlo; Soloviev, Sergiy; Baran, Rafal; Millot, Yannick; Dzwigaj, Stanislaw

2016-10-26

Silver has been identified in the framework of Ag x SiBEA zeolites (where x = 3-6 Ag wt%) by the combined use of XRD, 109 Ag MAS NMR, FTIR, diffuse reflectance UV-visible, EPR and XPS spectroscopy. The incorporation of Ag ions into the framework of SiBEA zeolite has been evidenced by XRD. The consumption of OH groups as a result of their reaction with the silver precursor has been monitored by FTIR and photoluminescence spectroscopy. The changes in the silver state as a function of Ag content and thermal and hydrogen treatment at 573 K have been identified by 109 Ag MAS NMR, EPR, DR UV-visible, TEM and XPS investigations. The acidity of AgSiBEA has been investigated by FTIR spectroscopy of adsorbed CO and pyridine used as probe molecules.

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

NASA Astrophysics Data System (ADS)

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.

Interfacial chemistry of a perfluoropolyether lubricant studied by XPS and TDS

NASA Technical Reports Server (NTRS)

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-).

Surface chemical properties of eutectic and frozen NaCl solutions probed by XPS and NEXAFS.

PubMed

Křepelová, Adéla; Huthwelker, Thomas; Bluhm, Hendrik; Ammann, Markus

2010-12-17

We study the surface of sodium chloride-water mixtures above, at, and below the eutectic temperature using X-ray photoelectron spectroscopy (XPS) and electron-yield near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The NaCl frozen solutions are mimicking sea-salt deposits in ice or snow. Sea-salt particles emitted from the oceans are a major contributor to the global aerosol burden and can act as a catalyst for heterogeneous chemistry or as cloud condensation nuclei. The nature of halogen ions at ice surfaces and their influence on surface melting of ice are of significant current interest. We found that the surface of the frozen solution, depending on the temperature, consists of ice and different NaCl phases, that is, NaCl, NaCl·2H(2)O, and surface-adsorbed water.

First planet confirmation with the exoplanet tracker

NASA Astrophysics Data System (ADS)

van Eyken, Julian C.; Ge, Jian C.; Mahadevan, Suvrath; DeWitt, Curtis; Ren, Deqing

2003-11-01

The Exoplanet Tracker (ET) is a new concept of instrument for measuring stellar radial velocity variations. ET is based on a dispersed fixed-delay interferometer, a combination of Michelson interferometer and medium resolution (R~6700) spectrograph which overlays interferometer fringes on a long-slit stellar spectrum. By measuring shifts in the fringes rather than the Doppler shifts in the absorption lines themselves, we are able to make accurate stellar radial velocity measurements with a high throughput and low cost instrument. The single-order operation of the instrument can also in principle allow multi-object observations. We plan eventually to conduct deep large scale surveys for extra-solar planets using this technique. We present confirmation of the planetary companion to 51Peg from our first stellar observations at the Kitt Peak 2.1m telescope, showing results consistent with previous observations. We outline the fundamentals of the instrument, and summarize our current progress in terms of accuracy and throughput.

Plutonian Moon confirmed

NASA Astrophysics Data System (ADS)

In late February, two separate observations confirmed the 1978 discovery by U.S. Naval Observatory scientist James W. Christy of a moon orbiting the planet Pluto. According to the U.S. Naval Observatory, these two observations were needed before the International Astronomical Society (IAS) would officially recognize the discovery.Two types of observations of the moon, which was named Charon after the ferryman in Greek mythology who carried the dead to Pluto's realm, were needed for confirmation: a transit, in which the moon passes in front of Pluto, and an occultation, in which the moon passes behind the planet. These two phenomena occur only during an 8-year period every 124 years that had been calculated to take place during 1984-1985. Both events were observed in late February.

A new endstation at the Swiss Light Source for ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy measurements of liquid solutions.

PubMed

Brown, Matthew A; Redondo, Amaia Beloqui; Jordan, Inga; Duyckaerts, Nicolas; Lee, Ming-Tao; Ammann, Markus; Nolting, Frithjof; Kleibert, Armin; Huthwelker, Thomas; Müächler, Jean-Pierre; Birrer, Mario; Honegger, Juri; Wetter, Reto; Wörner, Hans Jakob; van Bokhoven, Jeroen A

2013-07-01

A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutions and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II α lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented.

Retinal nerve fibre thickness measured with optical coherence tomography accurately detects confirmed glaucomatous damage.

PubMed

Hood, D C; Harizman, N; Kanadani, F N; Grippo, T M; Baharestani, S; Greenstein, V C; Liebmann, J M; Ritch, R

2007-07-01

To assess the accuracy of optical coherence tomography (OCT) in detecting damage to a hemifield, patients with hemifield defects confirmed on both static automated perimetry (SAP) and multifocal visual evoked potentials (mfVEP) were studied. Eyes of 40 patients with concomitant SAP and mfVEP glaucomatous loss and 25 controls underwent OCT retinal nerve fibre layer (RNFL), mfVEP and 24-2 SAP tests. For the mfVEP and 24-2 SAP, a hemifield was defined as abnormal based upon cluster criteria. On OCT, a hemifield was considered abnormal if one of the five clock hour sectors (3 and 9 o'clock excluded) was at <1% (red) or two were at <5% (yellow). Seventy seven (43%) of the hemifields were abnormal on both mfVEP and SAP tests. The OCT was abnormal for 73 (95%) of these. Only 1 (1%) of the 100 hemifields of the controls was abnormal on OCT. Sensitivity/specificity (one eye per person) was 95/98%. The OCT RNFL test accurately detects abnormal hemifields confirmed on both subjective and objective functional tests. Identifying abnormal hemifields with a criterion of 1 red (1%) or 2 yellow (5%) clock hours may prove useful in clinical practice.

New insights into micro/nanoscale combined probes (nanoAuger, μXPS) to characterize Ag/Au@SiO2 core-shell assemblies.

PubMed

Ledeuil, J B; Uhart, A; Soulé, S; Allouche, J; Dupin, J C; Martinez, H

2014-10-07

This work has examined the elemental distribution and local morphology at the nanoscale of core@shell Ag/Au@SiO2 particles. The characterization of such complex metal/insulator materials becomes more efficient when using an initial cross-section method of preparation of the core@shell nanoparticles (ion milling cross polisher). The originality of this route of preparation allows one to obtain undamaged, well-defined and planar layers of cross-cut nano-objects. Once combined with high-resolution techniques of characterization (XPS, Auger and SEM), the process appears as a powerful way to minimize charging effects and enhance the outcoming electron signal (potentially affected by the topography of the material) during analysis. SEM experiments have unambiguously revealed the hollow-morphology of the metal core, while Auger spectroscopy observations showed chemical heterogeneity within the particles (as silver and gold are randomly found in the core ring). To our knowledge, this is the first time that Auger nano probe spectroscopy has been used and successfully optimized for the study of some complex metal/inorganic interfaces at such a high degree of resolution (≈12 nm). Complementarily, XPS Au 4f and Ag 3d peaks were finally detected attesting the possibility of access to the whole chemistry of such nanostructured assemblies.

Reduced graphene oxide growth on 316L stainless steel for medical applications

NASA Astrophysics Data System (ADS)

Cardenas, L.; MacLeod, J.; Lipton-Duffin, J.; Seifu, D. G.; Popescu, F.; Siaj, M.; Mantovani, D.; Rosei, F.

2014-07-01

We report a new method for the growth of reduced graphene oxide (rGO) on the 316L alloy of stainless steel (SS) and its relevance for biomedical applications. We demonstrate that electrochemical etching increases the concentration of metallic species on the surface and enables the growth of rGO. This result is supported through a combination of Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), density functional theory (DFT) calculations and static water contact angle measurements. Raman spectroscopy identifies the G and D bands for oxidized species of graphene at 1595 cm-1 and 1350 cm-1, respectively, and gives an ID/IG ratio of 1.2, indicating a moderate degree of oxidation. XPS shows -OH and -COOH groups in the rGO stoichiometry and static contact angle measurements confirm the wettability of rGO. SEM and AFM measurements were performed on different substrates before and after coronene treatment to confirm rGO growth. Cell viability studies reveal that these rGO coatings do not have toxic effects on mammalian cells, making this material suitable for biomedical and biotechnological applications.

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

NASA Astrophysics Data System (ADS)

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.

X ray photoelectron spectroscopy (XPS) analysis of Photosensitive ZrO2 array

NASA Astrophysics Data System (ADS)

Li, Y.; Zhao, G.; Zhu, R.; Kou, Z.

2018-03-01

Based on organic zirconium source as the starting material, by adding chemical modifiers which are made up with photosensitive ZrO2 sol. A uniformed ZrO2 array dot was fabricated with a mean diameter of around 800 nm. By using UV-vis spectra and X-ray photoelectron spectroscopy analysis method, studies the photosensitive ZrO2 gel film of photochemical reaction process and the photosensitive mechanism, to determine the zirconium atom centered chelate structure, reaction formed by metal chelate Zr atom for the center, and to establish the molecular model of the chelate. And studied the ultraviolet light in the process of the variation of the XPS spectra, Zr3d5/2 to 184.9 eV corresponding to the binding energy of the as the combination of state peak gradually reduce; By combining with the status of Zr-O peak gradually increase; The strength of the peak is gradually decline. This suggests that in the process of ultraviolet light photo chemical reaction happened. This study is of great significance to the micro fabrication of ZrO2 array not only to the memory devices but also to the optical devices.

Struggling for confirmation--patients' experiences of dissatisfaction with hospital care.

PubMed

Eriksson, Ulrika; Svedlund, Marianne

2007-03-01

The aim of the study was to illuminate patients' experiences of dissatisfaction with hospital care. During the last decade, interest in measuring patient satisfaction has become an important indicator of the quality of care. Researchers have, however, criticized the concept theoretically and methodologically. Subsequently, researchers have increasingly argued that the focus of attention should shift to explore patient dissatisfaction. A qualitative approach. Narrative interviews were conducted with six people who had experienced dissatisfaction during a hospital care episode. The interview text was analysed using qualitative content analysis. The results show the patients' struggle for confirmation, the feeling of distrust in health care and what they have been forced to sacrifice because of lack of treatment. A feeling of being a troublesome patient is also apparent. At the same time a positive encounter is described, as well as situations of confirmation from caregivers. The results also show hope and a will to get on with life. Dissatisfaction relating to aspects of encounter is a common problem in health care and conceivable causes and possible solutions are discussed from different perspectives. RELEVANCE TO CLINICAL: Caregivers as well as patients are in need of confirmation. If management were to take notice of and confirm caregivers this could consequently help them to gain the strength and energy necessary to provide care permeated with confirmation. A veritable, trustworthy care can be established through personal presence. To take notice of, confirm and listen to patients, creates opportunities for providing them with a positive experience of human encounter, which in the long run is rewarding from all perspectives.

Retinal nerve fibre thickness measured with optical coherence tomography accurately detects confirmed glaucomatous damage

PubMed Central

Hood, D C; Harizman, N; Kanadani, F N; Grippo, T M; Baharestani, S; Greenstein, V C; Liebmann, J M; Ritch, R

2007-01-01

Aim To assess the accuracy of optical coherence tomography (OCT) in detecting damage to a hemifield, patients with hemifield defects confirmed on both static automated perimetry (SAP) and multifocal visual evoked potentials (mfVEP) were studied. Methods Eyes of 40 patients with concomitant SAP and mfVEP glaucomatous loss and 25 controls underwent OCT retinal nerve fibre layer (RNFL), mfVEP and 24‐2 SAP tests. For the mfVEP and 24‐2 SAP, a hemifield was defined as abnormal based upon cluster criteria. On OCT, a hemifield was considered abnormal if one of the five clock hour sectors (3 and 9 o'clock excluded) was at <1% (red) or two were at <5% (yellow). Results Seventy seven (43%) of the hemifields were abnormal on both mfVEP and SAP tests. The OCT was abnormal for 73 (95%) of these. Only 1 (1%) of the 100 hemifields of the controls was abnormal on OCT. Sensitivity/specificity (one eye per person) was 95/98%. Conclusions The OCT RNFL test accurately detects abnormal hemifields confirmed on both subjective and objective functional tests. Identifying abnormal hemifields with a criterion of 1 red (1%) or 2 yellow (5%) clock hours may prove useful in clinical practice. PMID:17301118

XPS and XANES studies of biomimetic composites based on B-type nano-hydroxyapatite

NASA Astrophysics Data System (ADS)

Goloshchapov, D. L.; Gushchin, M. S.; Kashkarov, V. M.; Seredin, P. V.; Ippolitov, Y. A.; Khmelevsky, N. O.; Aksenenko, A. Yu.

2018-06-01

The paper presents an investigation of the local atomic structure of nanocrystalline carbonate-substituted hydroxyapatite (CHAP) contained in biomimetic composites - analogues of intact human tooth tissues. Using the XPS technique, the presence of impurity Mg and F atoms and structurally bound carbon in CHAP, at the concentrations typical of apatite enamel and dentine was determined. The XANES method was used to study the changes occurring in P L2,3 spectra of biocomposites with CHAP, depending on the percentage of the amino acid matrix. The appearance of maxima in the spectra of XANES P L2,3 near 135.7 eV for the samples with the composition of amino acid complex/hydroxyapatite - 5/95, 25/75 and the splitting of a broad peak of 146.9 eV in the spectrum of a biocomposite with a composition of 40/60 indicates at the interaction of molecular complex of amino acids with atomic environment of phosphorus. This fact can be used in the fundamental medicine for synthesizing of new biomaterials in dentistry.

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

NASA Astrophysics Data System (ADS)

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.

A comprehensive study of catalytic, morphological and electronic properties of ligand-protected gold nanoclusters using XPS, STM, XAFS, and TPD techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Qiyuan; Cen, Jiajie; Zhao, Yue

Ultra-small gold nanoclusters were synthesized via a ligand exchange method and deposited onto different TiO2 supports to study their properties. STM imaging revealed that the as-synthesized gold nanoclusters had 2-D morphology consisting of monolayers of gold atoms. In conclusion, subsequent XPS, XAFS, and CO oxidation TPD results indicated that heat treatments of gold clusters at different temperatures significantly altered their electronic and catalytic properties due to ligand deprotection and cluster agglomeration.

A comprehensive study of catalytic, morphological and electronic properties of ligand-protected gold nanoclusters using XPS, STM, XAFS, and TPD techniques

DOE PAGES

Wu, Qiyuan; Cen, Jiajie; Zhao, Yue; ...

2017-12-08

Ultra-small gold nanoclusters were synthesized via a ligand exchange method and deposited onto different TiO2 supports to study their properties. STM imaging revealed that the as-synthesized gold nanoclusters had 2-D morphology consisting of monolayers of gold atoms. In conclusion, subsequent XPS, XAFS, and CO oxidation TPD results indicated that heat treatments of gold clusters at different temperatures significantly altered their electronic and catalytic properties due to ligand deprotection and cluster agglomeration.

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-12

Dr. Michael Griffin testifies, Tuesday, April 12, 2005, during his confirmation hearing before the U.S. Senate Commerce Committee at the Russell Senate Office Building in Washington. If confirmed, Griffin, who currently heads the space department at the Johns Hopkins University Applied Physics Laboratory will become NASA's 11th administrator. Photo Credit (NASA/Renee Bouchard)

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-11

Dr. Michael Griffin testifies, Tuesday, April 12, 2005, during his confirmation hearing before the U.S. Senate Commerce Committee at the Russell Senate Office Building in Washington. If confirmed, Griffin, who currently heads the space department at the Johns Hopkins University Applied Physics Laboratory will become NASA's 11th administrator. Photo Credit (NASA/Renee Bouchard)

Incorporation of low energy activated nitrogen onto HOPG surface: Chemical states and thermal stability studies by in-situ XPS and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Chandran, Maneesh; Shasha, Michal; Michaelson, Shaul; Hoffman, Alon

2016-09-01

In this paper we report the chemical states analysis of activated nitrogen incorporated highly oriented pyrolytic graphite (HOPG) surface under well-controlled conditions. Nitrogen incorporation is carried out by two different processes: an indirect RF nitrogen plasma and low energy (1 keV) N2+ implantation. Bonding configuration, concentration and thermal stability of the incorporated nitrogen species by aforesaid processes are systematically compared by in-situ X-ray photoelectron spectroscopy (XPS). Relatively large concentration of nitrogen is incorporated onto RF nitride HOPG surface (16.2 at.%), compared to N2+ implanted HOPG surface (7.7 at.%). The evolution of N 1s components (N1, N2, N3) with annealing temperature is comprehensively discussed, which indicates that the formation and reorganization of local chemical bonding states are determined by the process of nitridation and not by the prior chemical conditioning (i.e., amorphization or hydrogenation) of the HOPG surface. A combined XPS and Raman spectroscopy studies revealed that N2+ implantation process resulted in a high level of defects to the HOPG surface, which cannot be annealed-out by heat treatment up to 1000 °C. On the other hand, the RF nitrogen plasma process did not produce a high level of surface defects, while incorporating nearly the same amount of stable nitrogen species.

Americium(III) capture using phosphonic acid-functionalized silicas with different mesoporous morphologies: adsorption behavior study and mechanism investigation by EXAFS/XPS.

PubMed

Zhang, Wen; He, Xihong; Ye, Gang; Yi, Rong; Chen, Jing

2014-06-17

Efficient capture of highly toxic radionuclides with long half-lives such as Americium-241 is crucial to prevent radionuclides from diffusing into the biosphere. To reach this purpose, three different types of mesoporous silicas functionalized with phosphonic acid ligands (SBA-POH, MCM-POH, and BPMO-POH) were synthesized via a facile procedure. The structure, surface chemistry, and micromorphology of the materials were fully characterized by (31)P/(13)C/(29)Si MAS NMR, XPS, and XRD analysis. Efficient adsorption of Am(III) was realized with a fast rate to reach equilibrium (within 10 min). Influences including structural parameters and functionalization degree on the adsorption behavior were investigated. Slope analysis of the equilibrium data suggested that the coordination with Am(III) involved the exchange of three protons. Moreover, extended X-ray absorption fine structure (EXAFS) analysis, in combination with XPS survey, was employed for an in-depth probe into the binding mechanism by using Eu(III) as a simulant due to its similar coordination behavior and benign property. The results showed three phosphonic acid ligands were coordinated to Eu(III) in bidentate fashion, and Eu(P(O)O)3(H2O) species were formed with the Eu-O coordination number of 7. These phosphonic acid-functionalized mesoporous silicas should be promising for the treatment of Am-containing radioactive liquid waste.

An XPS study on the impact of relative humidity on the aging of UO 2 powders

DOE PAGES

Donald, Scott B.; Dai, Zurong R.; Davisson, M. Lee; ...

2017-02-10

High resolution x-ray photoemission spectroscopy (XPS) was used to characterize the chemical speciation of high purity uranium dioxide (UO 2) powder samples following aging for periods of up to one year under controlled conditions with relative humidity ranging from 34% to 98%. A systematic shift to higher uranium oxidation states, and thus an increase in the mean uranium valence, was found to directly correlate with the dose of water received (i.e. the product of exposure time and relative humidity). Exposure duration was found to have a greater impact on sample aging than relative humidity. Lastly, the sample aged at 98%more » relative humidity was found to have unique structural differences for exposure time beyond 180 days when observed by scanning electron microscopy (SEM).« less

An XPS study on the impact of relative humidity on the aging of UO 2 powders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donald, Scott B.; Dai, Zurong R.; Davisson, M. Lee

High resolution x-ray photoemission spectroscopy (XPS) was used to characterize the chemical speciation of high purity uranium dioxide (UO 2) powder samples following aging for periods of up to one year under controlled conditions with relative humidity ranging from 34% to 98%. A systematic shift to higher uranium oxidation states, and thus an increase in the mean uranium valence, was found to directly correlate with the dose of water received (i.e. the product of exposure time and relative humidity). Exposure duration was found to have a greater impact on sample aging than relative humidity. Lastly, the sample aged at 98%more » relative humidity was found to have unique structural differences for exposure time beyond 180 days when observed by scanning electron microscopy (SEM).« less

Intrinsic ferromagnetism in nanocrystalline Mn-doped ZnO depending on Mn concentration.

PubMed

Subramanian, Munisamy; Tanemura, Masaki; Hihara, Takehiko; Soga, Tetsuo; Jimbo, Takashi

2011-04-01

The physical properties of Zn(1-x)Mn(x)O nanoparticles synthesized by thermal decomposition are extensively investigated by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman light scattering and Hysteresis measurements. XRD and XPS spectra reveal the absence of secondary phase in nanocrystalline ZnO doped with 5% or less Mn; and, later confirms that the valance state of Mn to be 2+ for all the samples. Raman spectra exhibit a peak at 660 cm(-1) which we attribute to the intrinsic lattice defects of ZnO with increasing Mn concentration. Overall, our results demonstrate that ferromagnetic properties can be realized while Mn-doped ZnO obtained in the nanocrystalline form.

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-12

Dr. Michael Griffin, right, talks with his wife Rebecca Griffin prior to testifying at his confirmation hearing before the U.S. Senate Commerce Committee, Tuesday, April 12, 2005, at the Russell Senate Office Building in Washington. If confirmed, Griffin, who currently heads the space department at the Johns Hopkins University Applied Physics Laboratory will become NASA's 11th administrator. Photo Credit (NASA/Renee Bouchard)

InP/ZnS nanocrystals: coupling NMR and XPS for fine surface and interface description.

PubMed

Virieux, Héloïse; Le Troedec, Marianne; Cros-Gagneux, Arnaud; Ojo, Wilfried-Solo; Delpech, Fabien; Nayral, Céline; Martinez, Hervé; Chaudret, Bruno

2012-12-05

Advanced (1)H, (13)C, and (31)P solution- and solid-state NMR studies combined with XPS were used to probe, at the molecular scale, the composition (of the core, the shell, and the interface) and the surface chemistry of InP/ZnS core/shell quantum dots prepared via a non-coordinating solvent strategy. The interface between the mismatched InP and ZnS phases is composed of an amorphous mixed oxide phase incorporating InPO(x) (with x = 3 and predominantly 4), In(2)O(3), and InO(y)(OH)(3-2y) (y = 0, 1). Thanks to the analysis of the underlying reaction mechanisms, we demonstrate that the oxidation of the upper part of the InP core is the consequence of oxidative conditions brought by decarboxylative coupling reactions (ketonization). These reactions occur during both the core preparation and the coating process, but according to different mechanisms.

Electron-beam-induced post-grafting polymerization of acrylic acid onto the surface of Kevlar fibers

NASA Astrophysics Data System (ADS)

Xu, Lu; Hu, Jiangtao; Ma, Hongjuan; Wu, Guozhong

2018-04-01

The surface of Kevlar fibers was successfully modified by electron beam (EB)-induced post-grafting of acrylic acid (AA). The generation of radicals in the fibers was confirmed by electron spin resonance (ESR) measurements, and the concentration of radicals was shown to increase as the absorbed dose increased, but decrease with increasing temperature. The influence of the synthesis conditions on the degree of grafting was also investigated. The surface microstructure and chemical composition of the modified Kevlar fibers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed that the surface of the grafted fibers was rougher than those of the pristine and irradiated fibers. XPS analysis confirmed an increase in C(O)OH groups on the surface of the Kevlar fibers, suggesting successful grafting of AA. These results indicate that EB-induced post-grafting polymerization is effective for modifying the surface properties of Kevlar fibers.

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-12

U.S. Senator Daniel K. Inouye, D-Hawaii, left, speaks as U.S. Senator Ted Stevens, R-Alaska, looks on during the confirmation hearing for Dr. Michael Griffin, in front of the U.S. Senate Commerce Committee, Tuesday, April 12, 2005, in Washington. If confirmed, Griffin, who currently heads the space department at the Johns Hopkins University Applied Physics Laboratory will become NASA's 11th administrator. Photo Credit (NASA/Renee Bouchard)

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-12

U.S. Senator Barbara Mikulski, D-Md., testifies before the U.S. Senate Commerce Committee during the confirmation hearing of Dr. Michael Griffin, rear center, Tuesday, April 12, 2005, at the Russell Senate Office Building in Washington. Griffin currently heads the space department at Johns Hopkins University's Applied Physics Laboratory. If confirmed by the full U.S. Senate, Dr. Griffin would be NASA's 11th administrator. Photo Credit: (NASA/Renee Bouchard)

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-11

U.S. Senator Barbara Mikulski, D-Md., testifies before the U.S. Senate Commerce Committee during the confirmation hearing of Dr. Michael Griffin, rear center, Tuesday, April 12, 2005, at the Russell Senate Office Building in Washington. Griffin currently heads the space department at Johns Hopkins University's Applied Physics Laboratory. If confirmed by the full U.S. Senate, Dr. Griffin would be NASA's 11th administrator. Photo Credit: (NASA/Renee Bouchard)

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-12

U.S. Senator Barbara Mikulski, D-Md., testifies before the U.S. Senate Commerce Committee during the confirmation hearing of Dr. Michael Griffin, right background, Tuesday, April 12, 2005, at the Russell Senate Office Building in Washington. Griffin currently heads the space department at Johns Hopkins University's Applied Physics Laboratory. If confirmed by the full U.S. Senate, Dr. Griffin would be NASA's 11th administrator. Photo Credit: (NASA/Renee Bouchard)

Oxidation of MnO(100) and NaMnO2 formation: Characterization of Mn2+ and Mn3+ surfaces via XPS and water TPD

NASA Astrophysics Data System (ADS)

Feng, Xu; Cox, David F.

2018-09-01

The oxidation of clean and Na precovered MnO(100) has been investigated by X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and temperature programmed desorption (TPD) of adsorbed water. XPS results indicate that Mn3O4-like and Mn2O3-like surfaces can be formed by various oxidation treatments of clean and nearly-stoichiometric MnO(100), while a NaMnO2-like surface can be produced by the oxidation of MnO(100) pre-covered with multilayers of metallic Na. Water TPD results indicate that water adsorption/desorption is sensitive to the available oxidation states of surface Mn cations, and can be used to distinguish between surfaces exposing Mn2+and Mn3+ cations, or a combination of these oxidation states. Carbon dioxide and water TPD results from the NaMnO2-like surface indicate that pre-adsorbed water blocks the uptake of CO2, while water displaces pre-adsorbed CO2. No indication of a strong reactive interaction is observed between CO2, water and the NaMnO2-like surface under the conditions of our study.

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

NASA Astrophysics Data System (ADS)

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.

Confirmed glyburide poisoning from ingestion of "street Valium".

PubMed

Lung, Derrick D; Gerona, Roy R; Wu, Alan H B; Smollin, Craig G

2012-08-01

Pharmaceuticals with little to no abuse potential are often sold surreptitiously as drugs of abuse on the street. Anecdotally, sulfonylureas are suspected to be commonly sold as "street Valium." Two patients presented with altered mental status and persistent hypoglycemia requiring continuous intravenous dextrose, in the context of suspected attempted benzodiazepine abuse. Supratherapeutic glyburide levels of 1198 and 647 ng/mL were measured in these patients. These are two cases of glyburide poisonings from ingestion of "street Valium" that have been confirmed by laboratory testing. Copyright © 2012. Published by Elsevier Inc.

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Technical Reports Server (NTRS)

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.

Surface chemical composition of human maxillary first premolar as assessed by X-ray photoelectron spectroscopy (XPS)

NASA Astrophysics Data System (ADS)

Lou, Leo; Nelson, Alan E.; Heo, Giseon; Major, Paul W.

2008-08-01

The surface chemical composition of dental enamel has been postulated as a contributing factor in the variation of bond strength of brackets bonded to teeth, and hence, the probability of bracket failure during orthodontic treatment. This study systematically investigated the chemical composition of 98 bonding surfaces of human maxillary premolars using X-ray photoelectron spectroscopy (XPS) to ascertain compositional differences between right and left first premolars. The major elements detected in all samples were calcium, phosphorus, oxygen, nitrogen and carbon. Surface compositions were highly variable between samples and several elements were found to be highly correlated. No statistical significant difference in the chemical composition of the maxillary right and left first premolars was found ( p > 0.05). Knowledge of the chemical composition of enamel surfaces will facilitate future studies that relate this information to the variations in dental enamel bond strength.

Assessment of clinical symptoms in household contacts of confirmed pertussis cases.

PubMed

Domínguez, Angela; Soldevila, Núria; Caylà, Joan A; García-Cenoz, Manuel; Ferrús, Glòria; Sala-Farré, Maria Rosa; Álvarez, Josep; Carol, Mònica; Barrabeig, Irene; Camps, Neus; Coronas, Lorena; Muñoz-Almagro, Carmen; Godoy, Pere

2017-11-01

We assessed the value of the clinical symptoms included in the case definition of pertussis in household contacts of laboratory-confirmed cases. A prospective epidemiological study was made in two Spanish regions. Household contacts were identified for each confirmed case reported during 2012 and 2013. Two clinical samples were taken to determine the presence or absence of Bordetella pertussis by culture or real-time PCR. Clinical variables, age and vaccination status were recorded. Positive and negative likelihood ratios (PLR, NLR) were estimated for each symptom. 2852 household contacts of 688 confirmed cases were reported. 178 household contacts with clinical symptoms were analyzed: 150 were laboratory confirmed and 28 were not. The clinical symptom with the highest PLR in comparison with the NLR was paroxysmal cough(PLR 4.76; 95% CI 1.91-11.87 and NLR 0.37; 95% CI 0.28-0.49). The contrast between the PLR and NLR was especially important for persons aged <18 years (PLR 7.08; 95% CI 1.10-45.74 and NLR 0.32; 95% CI 0.21-0.49). The clinical symptoms of pertussis are poor predictors of pertussis disease, independently of the vaccination status. Differences were observed between persons aged <18 years and adults. To adopt the appropriate treatment and control measures, rapid laboratory confirmation by PCR of all household contacts of confirmed cases who present any clinical symptoms compatible with pertussis should be recommended. Copyright © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshimoto, Shinya, E-mail: yosshi@issp.u-tokyo.ac.jp; Shiozawa, Yuichiro; Koitaya, Takanori

Electronic states and electrical conductivity of the native oxide Si(111) surface adsorbed with an electron donor tetrakis(dimethylamino)ethylene (TDAE) were investigated using ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy (XPS), and independently driven four-probe conductivity measurements. The formation of positively charged TDAE species is confirmed by the downward shift of the vacuum level by 1.45 eV, the absence of HOMO level in the valence band, and observation of the positively charged state in the N 1s XPS spectra. Si 2p XPS spectra and four-probe conductivity measurements revealed that TDAE adsorption induces an increase in downward band bending and a reduction in electrical resistancemore » of the surface, respectively. The sheet conductivity and the electron density of the surface are 1.1 μS/◻ and 4.6 × 10{sup 9} cm{sup −2}, respectively, after TDAE adsorption, and they are as high as 350% of the original surface. These results demonstrate that the electron density of the semiconductor surface is successfully controlled by the electron donor molecule TDAE.« less

As-Received, Ozone Cleaned and Ar+ Sputtered Surfaces of Hafnium Oxide Grown by Atomic Layer Deposition and Studied by XPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelhard, Mark H.; Herman, Jacob A.; Wallace, Robert

2012-06-27

In this study, X-ray photoelectron spectroscopy (XPS) characterization was performed on 47 nm thick hafnium oxide (HfO{sub 2}) films grown by atomic layer deposition using TEMA-Hf/H{sub 2}O at 250 C substrate temperature. HfO{sub 2} is currently being studied as a possible replacement for Silicon Oxide (SiO{sub 2}) as a gate dielectric in electronics transistors. XPS spectra were collected on a Physical Electronics Quantum 2000 Scanning ESCA Microprobe using a monochromatic Al K{sub a} X-ray (1486.7 eV) excitation source. The sample was analyzed under the following conditions: as received, after UV irradiation for five minutes, and after sputter cleaning with 2more » kV Ar{sup +} ions for 180 seconds. Survey scans showed carbon, oxygen, and hafnium as the major species in the film, while the only minor species of argon and carbide was detected after sputtering. Adventitious carbon initially composed approximately 18.6 AT% of the surface, but after UV cleaning it was reduced to 2.4 AT%. This demonstrated that that the majority of carbon was due to adventitious carbon. However, after 2 kV Ar{sup +} sputtering there was still only trace amounts of carbon at {approx}1 AT%, Some of this trace carbon is now in the form of a carbide due to the interaction with Ar{sup +} used for sputter cleaning. Furthermore, the stoiciometric ratio of oxygen and hafnium is consistent with a high quality HfO{sub 2} film.« less

Time-dependent investigation of sub-monolayers of Ni on Pd using Positron-annihilation induced Auger Electron Spectroscopy and XPS

NASA Astrophysics Data System (ADS)

Zimnik, Samantha; Piochacz, Christian; Vohburger, Sebastian; Hugenschmidt, Christoph

2016-01-01

The surface of a polycrystalline Pd-substrate covered with (sub-) monolayers of Ni was investigated with Positron-annihilation induced Auger Electron Spectroscopy (PAES). Comparative studies using conventional AES induced by electrons and X-rays showed the outstanding surface sensitivity of PAES. Time-dependent PAES was performed on a 0.5 ML Ni cover layer on Pd and compared with conventional X-ray induced Photoelectron Spectroscopy (XPS) in order to observe changes in the elemental composition of the surface. The PAES results appear to show a migration of Ni atoms into the Pd substrate, whereas the Ni signal shows a decrease of 12% within 13 h with respect to the initial value.

Study of sintering behavior of vapor forms of 1-octanethiol coated copper nanoparticles for application to ink-jet printing technology.

PubMed

Kwon, Jinhyeong; Park, Shinyoung; Haque, Md Mominul; Kim, Young-Seok; Lee, Caroline Sunyong

2012-04-01

Sub-50 nm copper nanoparticles coated with sub-5 nm 1-octanethiol layer for oxidation inhibition were examined to confirm the 1-octanethiol removal temperature as the sub-50 nm copper nanoparticles are sintered. As a result, 1-octanethiol Self-Assembled Multi-layers (SAMs) on sub-50 nm copper nanoparticles were successfully removed before sintering of copper nanoparticles so that a high density of copper line could be obtained. Finally, the line resistivity was measured and compared to verify the effect of sintering in different atmospheres. As a result, electrical resistivity of the copper pattern sintered in hydrogen atmosphere was measured at 6.96 x 10(-6) ohm-cm whereas that of the copper pattern sintered in mixed gas atmosphere was measured at 2.62 x 10(-5) ohm-cm. Thus, sintering of copper patterns was successfully done to show low electrical resistivity values. Moreover, removal of 1-octanethiol coating after sintering process was confirmed using X-ray photoelectron spectroscopy (XPS) analysis. By showing no sulfur content, XPS results indicate that 1-octanethiol is completely removed. Therefore, the vapor form of 1-octanethiol coating layers can be safely used as an oxidation inhibition layer for low temperature sintering processes and ink-jet applications.

Solution chemistry of carbonate minerals and its effects on the flotation of hematite with sodium oleate

NASA Astrophysics Data System (ADS)

Li, Dong; Yin, Wan-zhong; Xue, Ji-wei; Yao, Jin; Fu, Ya-feng; Liu, Qi

2017-07-01

The effects of carbonate minerals (dolomite and siderite) on the flotation of hematite using sodium oleate as a collector were investigated through flotation tests, supplemented by dissolution measurements, solution chemistry calculations, zeta-potential measurements, Fourier transform infrared (FTIR) spectroscopic studies, and X-ray photoelectron spectroscopy (XPS) analyses. The results of flotation tests show that the presence of siderite or dolomite reduced the recovery of hematite and that the inhibiting effects of dolomite were stronger. Dissolution measurements, solution chemistry calculations, and flotation tests confirmed that both the cations (Ca2+ and Mg2+) and CO3 2- ions dissolved from dolomite depressed hematite flotation, whereas only the CO3 2- ions dissolved from siderite were responsible for hematite depression. The zeta-potential, FTIR spectroscopic, and XPS analyses indicated that Ca2+, Mg2+, and CO3 2- (HCO3 -) could adsorb onto the hematite surface, thereby hindering the adsorption of sodium oleate, which was the main reason for the inhibiting effects of carbonate minerals on hematite flotation.

Structural and magnetic characterization of copper sulfonated phthalocyanine grafted onto treated polyethylene

NASA Astrophysics Data System (ADS)

Reznickova, A.; Kolska, Z.; Orendac, M.; Cizmar, E.; Sajdl, P.; Svorcik, V.

2016-08-01

This study focuses on high density polyethylene (HDPE) activated by Ar plasma treatment, subsequently grafted with copper sulfonated phthalocyanine (CuPc) especially pointing out to the surface and magnetic properties of those composites. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, zeta potential and by electron spin resonance (ESR). XPS analysis confirmed the successful grafting of phthalocyanine. The highest absorption was found for the sample grafted with bCuPc for 1 h. Electrokinetic analysis also confirmed the plasma treatment and also subsequent CuPc grafting influence significantly the surface chemistry and charge. These results correspond well with XPS determination. ESR studies confirmed the presence of CuPc grafted on HDPE. It was found, that grafting is mediated by magnetically inactive functional groups, rather than radicals. Magnetic properties of CuPc do not seem to change significantly after grafting CuPc on polyethylene surface.

A Multi-technique Characterization of Adsorbed Protein Films: Orientation and Structure by ToF-SIMS, NEXAFS, SFG, and XPS

NASA Astrophysics Data System (ADS)

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

Senate Confirmation Hearing IG

NASA Image and Video Library

2009-10-14

Paul K. Martin, nominee for Inspector General for NASA, answers questions during his confirmation hearing in front of the Senate Committee on Commerce, Science and Transportation, Thursday, Oct. 15, 2009, on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

Lori Garver Confirmation Hearing

NASA Image and Video Library

2009-07-07

Lori Garver, nominee for Deputy Administrator of NASA, testifies at her confirmation hearing before the Senate Commerce, Science and Transportation Committee in the Russell Senate Office Building on Capitol Hill in Washington, Wednesday, July 8, 2009. Photo Credit: (NASA/Bill Ingalls)

Charles Bolden Confirmation Hearing

NASA Image and Video Library

2009-07-07

Charles Bolden, nominee for Administrator of NASA, testifies at his confirmation hearing before the Senate Commerce, Science and Transportation Committee in the Russell Senate Office Building on Capitol Hill in Washington, Wednesday, July 8, 2009. Photo Credit: (NASA/Bill Ingalls)

Installation Restoration Program. Phase II: Stage 1 Problem Confirmation Study, Duluth International Airport, Duluth, Minnesota.

DTIC Science & Technology

1984-10-01

8 iii "i t-. Table of Contents (cont.) Section Title Page -APPENDIX A Acronyms, Definitions, Nomenclature and Units of Measure B Scope of Work, Task...Identification/Records Search Phase II - Problem Confirmation and Quantification Phase III - Technology Base Development Phase IV - Corrective Action Only...Problem Identification/Records Search Phase II - Problem Confirmation and Quantification Phase III - Technology Base Development Phase IV - Corrective

XPS and NRA investigations during the fabrication of gold nanostructured functionalized screen-printed sensors for the detection of metallic pollutants

NASA Astrophysics Data System (ADS)

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.

Senate Confirmation Hearing CFO

NASA Image and Video Library

2009-10-14

Dr. Elizabeth M. Robinson, nominee for Chief Financial Officer for NASA, answers questions during her confirmation hearing in front of the Senate Committee on Commerce, Science and Transportation, Thursday, Oct. 15, 2009, on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

Charles Bolden Confirmation Hearing

NASA Image and Video Library

2009-07-07

Charles Bolden, nominee for Administrator of NASA, waits for his turn to testify at his confirmation hearing before the Senate Commerce, Science and Transportation Committee in the Russell Senate Office Building on Capitol Hill in Washington, Wednesday, July 8, 2009. Photo Credit: (NASA/Bill Ingalls)

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

NASA Technical Reports Server (NTRS)

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.

Student-to-Student Confirmation in the College Classroom: An Initial Investigation of the Dimensions and Outcomes of Students' Confirming Messages

ERIC Educational Resources Information Center

Johnson, Zac D.; LaBelle, Sara

2016-01-01

The current study sought to determine dimensions of student-to-student confirmation. Results of open-ended surveys revealed that students confirm one another in unique ways based on the setting of their relationship (the classroom). Findings revealed three dimensions of student-to-student confirmation (acknowledgment, assistance, and individual…

Pharmaceutical identifier confirmation via DART-TOF.

PubMed

Easter, Jacob L; Steiner, Robert R

2014-07-01

Pharmaceutical analysis comprises a large amount of the casework in forensic controlled substances laboratories. In order to reduce the time of analysis for pharmaceuticals, a Direct Analysis in Real Time ion source coupled with an accurate mass time-of-flight (DART-TOF) mass spectrometer was used to confirm identity. DART-TOF spectral data for pharmaceutical samples were analyzed and evaluated by comparison to standard spectra. Identical mass pharmaceuticals were differentiated using collision induced dissociation fragmentation, present/absent ions, and abundance comparison box plots; principal component analysis (PCA) and linear discriminant analysis (LDA) were used for differentiation of identical mass mixed drug spectra. Mass assignment reproducibility and robustness tests were performed on the DART-TOF spectra. Impacts on the forensic science community include a decrease in analysis time over the traditional gas chromatograph/mass spectrometry (GC/MS) confirmations, better laboratory efficiency, and simpler sample preparation. Using physical identifiers and the DART-TOF to confirm pharmaceutical identity will eliminate the use of GC/MS and effectively reduce analysis time while still complying with accepted analysis protocols. This will prove helpful in laboratories with large backlogs and will simplify the confirmation process. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

First Planet Confirmation with a Dispersed Fixed-Delay Interferometer

NASA Astrophysics Data System (ADS)

van Eyken, J. C.; Ge, J.; Mahadevan, S.; DeWitt, C.

2004-01-01

The Exoplanet Tracker is a prototype of a new type of fiber-fed instrument for performing high-precision relative Doppler measurements to detect extrasolar planets. A combination of Michelson interferometer and medium-resolution spectrograph, this low-cost instrument facilitates radial velocity measurements with high throughput over a small bandwidth (~300 Å) and has the potential to be designed for multiobject operation with moderate bandwidths (~1000 Å). We present the first planet detection with this new type of instrument, a successful confirmation of the well-established planetary companion to 51 Peg, showing an rms precision of 11.5 m s-1 over 5 days. We also show comparison measurements of the radial velocity stable star, η Cas, showing an rms precision of 7.9 m s-1 over 7 days. These new results are starting to approach the precision levels obtained with traditional radial velocity techniques based on cross-dispersed echelles. We anticipate that this new technique could have an important impact in the search for extrasolar planets.

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

NASA Astrophysics Data System (ADS)

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.

Knapp confirmed as NSF Director

NASA Astrophysics Data System (ADS)

Edward A. Knapp was confirmed by the Senate in a voice vote on April 15 as the director of the National Science Foundation (NSF). The Senate vote followed a confirmation hearing by the Senate Labor and Human Resources Committee. Knapp, who was nominated by President Reagan to head the foundation in November, had been assistant director for NSF's mathematical and physical sciences (MPS) directorate since July 1982.Allegations that he has been politicizing NSF have beleaguered Knapp since he asked for resignations or firm commitments to leave from three NSF top administrators in December (two of these administrators had been planning to leave, though no resignation dates had been set). Knapp assured the Senate committee during the April 13 confirmation hearings that he made the decision to ask for the resignations and that, although he had discussed his plan with Office of Science and Technology Policy officials, they did not request that certain people be removed in exchange for particular increases in the NSF budget. Knapp consistently has defended himself against the allegations by saying that he wants his own team at the agency.

Surface analysis characterisation of gum binders used in modern watercolour paints

NASA Astrophysics Data System (ADS)

Sano, Naoko; Cumpson, Peter J.

2016-02-01

Conducting this study has demonstrated that not only SEM-EDX but also XPS can be an efficient tool for characterising watercolour paint surfaces. We find that surface effects are mediated by water. Once the powdered components in the watercolour come into contact with water they dramatically transform their chemical structures at the surface and show the presence of pigment components with a random dispersion within the gum layer. Hence the topmost surface of the paint is confirmed as being composed of the gum binder components. This result is difficult to confirm using just one analytical technique (either XPS or SEM-EDX). In addition, peak fitting of C1s XPS spectra suggests that the gum binder in the commercial watercolour paints is probably gum arabic (by comparison with the reference materials). This identification is not conclusive, but the combination techniques of XPS and SEM shows the surface structure with material distribution of the gum binder and the other ingredients of the watercolour paints. Therefore as a unique technique, XPS combined with SEM-EDX may prove a useful method in the study of surface structure for not only watercolour objects but also other art objects; which may in future help in the conservation for art.

XPS analysis of Al/EPDM bondlines from IUS SRM-1 polar bosses

NASA Astrophysics Data System (ADS)

Hemminger, Carol S.; Marquez, Nicholas

1993-03-01

A temperature-stress rupture method using partial immersion in liquid nitrogen was developed for the aluminum/EPDM rubber insulation bondline of the IUS SRM-1 polar bosses in order to investigate a corrosion problem. Subsequent XPS analysis of the ruptured bondline followed changes in the locus of failure as corrosion progressed. Samples from the forward polar bosses had a predominantly noncorroded appearance on the ruptured surfaces. The locus of failure was predominantly through the primer layer, which is distinguished by a high concentration of chlorinated hydrocarbon. The aft polar boss segments analyzed were characterized by the presence of corrosion over the entire mid-section of the ruptured aluminum to insulation bondline. The predominant corrosion product detected was aluminum oxide/hydroxide. The corroded bondline sections had significantly higher concentrations of aluminum oxide/hydroxide than the noncorroded areas, and lower concentrations of primer material. The temperature-stress rupture appeared to progress most readily through areas of thickened aluminum oxide/hydroxide infiltrated into the primer layer. In general there was a very good correlation between the calculated Cl:Al atomic % ratio, and the visual characterization of the extent of corrosion. The Cl:Al ratio, which represents the primer to corrosion product ratio at the locus of failure, varied from 0.4 to 47. With only a few exceptions, surfaces with a predominantly noncorroded appearance had Cl:Al ratios greater than 2, and surfaces with a heavily corroded appearance had Cl:Al ratios less than 1.

Measure Guideline: Installing Rigid Foam Insulation on the Interior of Existing Brick Walls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Natarajan, H.; Klocke, S.; Puttagunta, S.

2012-06-01

This measure guideline provides information on an effective method to insulate the interior of existing brick masonry walls with extruded polystyrene (XPS) insulation board. The guide outlines step-by-step design and installation procedures while explaining the benefits and tradeoffs where applicable. The authors intend that this document be useful to a varied audience that includes builders, remodelers, contractors and homeowners.

Measure Guideline. Installing Rigid Foam Insulation on the Interior of Existing Brick Walls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Natarajan, Hariharan; Klocke, Steve; Puttagunta, Srikanth

2012-06-01

This measure guideline provides information on an effective method to insulate the interior of existing brick masonry walls with extruded polystyrene (XPS) insulation board. The guide outlines step-by-step design and installation procedures while explaining the benefits and tradeoffs where applicable. The authors intend that this document be useful to a varied audience that includes builders,remodelers, contractors and homeowners.

Lori Garver Confirmation Hearing

NASA Image and Video Library

2009-07-07

Charles Bolden, nominee for Administrator of NASA, left, and Lori Garver, Nominee for Deputy Administrator of NASA, testify at their confirmation hearing before the Senate Commerce, Science and Transportation Committee in the Russell Senate Office Building on Capitol Hill in Washington, Wednesday, July 8, 2009. Photo Credit: (NASA/Bill Ingalls)

Senate Confirmation Hearing CFO

NASA Image and Video Library

2009-10-14

U.S. Sen. Maria Cantwell, D-Wash., left, talks about Dr. Elizabeth M. Robinson, nominee for Chief Financial Officer for NASA, right, prior to her confirmation hearing in front of the Senate Committee on Commerce, Science and Transportation, Thursday, Oct. 15, 2009, on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

Charles Bolden Confirmation Hearing

NASA Image and Video Library

2009-07-07

Charles Bolden, nominee for Administrator of NASA, left, and Lori Garver, nominee for Deputy Administrator of NASA, listen to Senators questions at their confirmation hearing before the Senate Commerce, Science and Transportation Committee in the Russell Senate Office Building on Capitol Hill in Washington, Wednesday, July 8, 2009. Photo Credit: (NASA/Bill Ingalls)

Culture confirmation of tuberculosis cases in Birmingham, UK.

PubMed

Hayer, Kalbir S; Sitch, Alice J; Dedicoat, Martin; Wood, Annette L

2013-10-01

The proportion of culture-confirmed tuberculosis (TB) cases in Birmingham had gradually decreased to less than 65% in 2008. Reasons for this were unclear, therefore this study assessed diagnostic methods used for confirming TB and reviewed factors involved in positive culture. A cross-sectional study was carried out. A list of notified TB cases for Birmingham in those aged 16 y and over in 2009 was collated. Where no positive culture was recorded, further data were collected from hospital databases and case notes. Of 449 TB cases, 419 (93%) had samples taken for culture testing. Of all cases, 309 (69%) were confirmed by culture testing; of those receiving culture testing, 73% were confirmed. Pulmonary TB was identified as a predictor of positive culture in both the unadjusted and adjusted analyses: odds ratio (OR) 2.05, 95% confidence interval (CI) 1.32-3.19, and OR 2.32, 95% CI 1.29-4.17, respectively. Gender, age, ethnicity, UK born, and treatment delay were not significantly associated with positive culture. Of 140 cases not confirmed by culture, 129 (92%) had their diagnosis supported by at least one other test. The vast majority of TB cases had microbiological specimens taken to help confirm the disease. Furthermore, culture confirmation rates in Birmingham were meeting national targets in 2009. However culture confirmation rates were significantly lower in extrapulmonary TB, therefore further work is suggested in this group. The role of other investigations (e.g. interferon-gamma release assay (IGRA), Mantoux) is unclear. Further collaboration between clinicians, histopathologists, and microbiologists is advised to ensure samples are sent appropriately and culture confirmation is optimized.

Performance Confirmation Data Aquisition System

DOE Office of Scientific and Technical Information (OSTI.GOV)

D.W. Markman

2000-10-27

The purpose of this analysis is to identify and analyze concepts for the acquisition of data in support of the Performance Confirmation (PC) program at the potential subsurface nuclear waste repository at Yucca Mountain. The scope and primary objectives of this analysis are to: (1) Review the criteria for design as presented in the Performance Confirmation Data Acquisition/Monitoring System Description Document, by way of the Input Transmittal, Performance Confirmation Input Criteria (CRWMS M&O 1999c). (2) Identify and describe existing and potential new trends in data acquisition system software and hardware that would support the PC plan. The data acquisition softwaremore » and hardware will support the field instruments and equipment that will be installed for the observation and perimeter drift borehole monitoring, and in-situ monitoring within the emplacement drifts. The exhaust air monitoring requirements will be supported by a data communication network interface with the ventilation monitoring system database. (3) Identify the concepts and features that a data acquisition system should have in order to support the PC process and its activities. (4) Based on PC monitoring needs and available technologies, further develop concepts of a potential data acquisition system network in support of the PC program and the Site Recommendation and License Application.« less

Measuring Compositions in Organic Depth Profiling: Results from a VAMAS Interlaboratory Study.

PubMed

Shard, Alexander G; Havelund, Rasmus; Spencer, Steve J; Gilmore, Ian S; Alexander, Morgan R; Angerer, Tina B; Aoyagi, Satoka; Barnes, Jean-Paul; Benayad, Anass; Bernasik, Andrzej; Ceccone, Giacomo; Counsell, Jonathan D P; Deeks, Christopher; Fletcher, John S; Graham, Daniel J; Heuser, Christian; Lee, Tae Geol; Marie, Camille; Marzec, Mateusz M; Mishra, Gautam; Rading, Derk; Renault, Olivier; Scurr, David J; Shon, Hyun Kyong; Spampinato, Valentina; Tian, Hua; Wang, Fuyi; Winograd, Nicholas; Wu, Kui; Wucher, Andreas; Zhou, Yufan; Zhu, Zihua; Cristaudo, Vanina; Poleunis, Claude

2015-08-20

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the measurement of composition in organic depth profiling. Layered samples with known binary compositions of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro-l-phenylalanine in each layer were manufactured in a single batch and distributed to more than 20 participating laboratories. The samples were analyzed using argon cluster ion sputtering and either X-ray photoelectron spectroscopy (XPS) or time-of-flight secondary ion mass spectrometry (ToF-SIMS) to generate depth profiles. Participants were asked to estimate the volume fractions in two of the layers and were provided with the compositions of all other layers. Participants using XPS provided volume fractions within 0.03 of the nominal values. Participants using ToF-SIMS either made no attempt, or used various methods that gave results ranging in error from 0.02 to over 0.10 in volume fraction, the latter representing a 50% relative error for a nominal volume fraction of 0.2. Error was predominantly caused by inadequacy in the ability to compensate for primary ion intensity variations and the matrix effect in SIMS. Matrix effects in these materials appear to be more pronounced as the number of atoms in both the primary analytical ion and the secondary ion increase. Using the participants' data we show that organic SIMS matrix effects can be measured and are remarkably consistent between instruments. We provide recommendations for identifying and compensating for matrix effects. Finally, we demonstrate, using a simple normalization method, that virtually all ToF-SIMS participants could have obtained estimates of volume fraction that were at least as accurate and consistent as XPS.

Measuring Compositions in Organic Depth Profiling: Results from a VAMAS Interlaboratory Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shard, A. G.; Havelund, Rasmus; Spencer, Steve J.

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the measurement of composition in organic depth profiling. Layered samples with known binary compositions of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro-L-phenylalanine in each layer were manufactured in a single batch and distributed to more than 20 participating laboratories. The samples were analyzed using argon cluster ion sputtering and either X-ray Photoelectron Spectroscopy (XPS) or Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) to generate depth profiles. Participants were asked to estimate the volume fractions in two of the layers and were provided withmore » the compositions of all other layers. Participants using XPS provided volume fractions within 0.03 of the nominal values. Participants using ToF-SIMS either made no attempt, or used various methods that gave results ranging in error from 0.02 to over 0.10 in volume fraction, the latter representing a 50% relative error for a nominal volume fraction of 0.2. Error was predominantly caused by inadequacy in the ability to compensate for primary ion intensity variations and the matrix effect in SIMS. Matrix effects in these materials appear to be more pronounced as the number of atoms in both the primary analytical ion and the secondary ion increase. Using the participants’ data we show that organic SIMS matrix effects can be measured and are remarkably consistent between instruments. We provide recommendations for identifying and compensating for matrix effects. Finally we demonstrate, using a simple normalization method, that virtually all ToF-SIMS participants could have obtained estimates of volume fraction that were at least as accurate and consistent as XPS.« less

A ToF-SIMS and XPS study of protein adsorption and cell attachment across PEG-like plasma polymer films with lateral compositional gradients

NASA Astrophysics Data System (ADS)

Menzies, Donna J.; Jasieniak, Marek; Griesser, Hans J.; Forsythe, John S.; Johnson, Graham; McFarland, Gail A.; Muir, Benjamin W.

2012-12-01

In this work we report a detailed X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) study of poly(ethylene glycol) PEG-like chemical gradients deposited via plasma enhanced chemical vapour deposition (PECVD) at two different load powers using diethylene glycol dimethyl ether (DG) as a monomer. Principal component analysis (PCA) was applied to the ToF-SIMS data both before and after protein adsorption on the plasma polymer thin films. Results of the PCA loadings indicated a higher content of hydrocarbon fragments across the higher load power gradient, which adsorbed higher amounts of proteins. Gradients deposited at a lower load power retained a higher degree of monomer like functionality as did the central region directly underneath the knife edge electrode. Analysis of the adsorption of serum proteins (human serum albumin and fetal bovine serum) was monitored across the gradient films and increased with decreasing ether (PEG-like) film chemistries. The effect of protein incubation time on the levels adsorbed fetal bovine serum on the plasma polymer films was critical, with significantly more protein adsorbing after 24 hour incubation times on both gradient films. The attachment of HeLa cells on the gradients appeared to be dictated not only by the surface chemistry, but also by the adsorption of serum proteins. XPS analysis revealed that at surface ether concentrations of less than 70% in the gradient films, significant increases in protein and cell attachment were observed.

Nanostructured PdO Thin Film from Langmuir-Blodgett Precursor for Room-Temperature H2 Gas Sensing.

PubMed

Choudhury, Sipra; Betty, C A; Bhattacharyya, Kaustava; Saxena, Vibha; Bhattacharya, Debarati

2016-07-06

Nanoparticulate thin films of PdO were prepared using the Langmuir-Blodgett (LB) technique by thermal decomposition of a multilayer film of octadecylamine (ODA)-chloropalladate complex. The stable complex formation of ODA with chloropalladate ions (present in subphase) at the air-water interface was confirmed by the surface pressure-area isotherm and Brewster angle microscopy. The formation of nanocrystalline PdO thin film after thermal decomposition of as-deposited LB film was confirmed by X-ray diffraction and Raman spectroscopy. Nanocrystalline PdO thin films were further characterized by using UV-vis and X-ray photoelectron spectroscopic (XPS) measurements. The XPS study revealed the presence of prominent Pd(2+) with a small quantity (18%) of reduced PdO (Pd(0)) in nanocrystalline PdO thin film. From the absorption spectroscopic measurement, the band gap energy of PdO was estimated to be 2 eV, which was very close to that obtained from specular reflectance measurements. Surface morphology studies of these films using atomic force microscopy and field-emission scanning electron microscopy indicated formation of nanoparticles of size 20-30 nm. These PdO film when employed as a chemiresistive sensor showed H2 sensitivity in the range of 30-4000 ppm at room temperature. In addition, PdO films showed photosensitivity with increase in current upon shining of visible light.

Catalytic activity of Ru-Sn/Al2O3 in reduction reaction of pollutant 4-Nitrophenol

NASA Astrophysics Data System (ADS)

Rini, A. S.; Radiman, S.; Yarmo, M. A.

2018-03-01

Ru-Sn/Al2O3 bimetallic nanocatalysts have been synthesized by using conventional and microwave impregnation methods. Structure and morphology of the samples were characterized using XRD, XPS, and TEM. XRD and XPS measurement have confirmed the presence of Ru and Sn in the samples. According to TEM results, the morphology of the catalyst strongly depends on the preparation route and stabilizing agent (i.e. PVP). The sample with PVP (polyvinylpyrrolidone) has better nanoparticles distribution over the support. A sample prepared by conventional method has an agglomeration of nanoparticles on the support. Catalytic activities of both samples were examined in the reduction reaction of pollutant, i.e. 4-nitrophenol. Catalytic examination showed that reaction rate of 4-nitrophenol reduction by using microwave-assisted sample has improved 3.5 times faster than conventional impregnation sample.

Senate Confirmation Hearing IG

NASA Image and Video Library

2009-10-14

Paul K. Martin, nominee for Inspector General at NASA, right, answers questions during his confirmation hearing in front of the Senate Committee on Commerce, Science and Transportation, Thursday, Oct. 15, 2009, on Capitol Hill in Washington. At left is Dr. Elizabeth M. Robinson, nominee for Chief Financial Officer for NASA. Photo Credit: (NASA/Paul E. Alers)

Sorption of Eu(III) on attapulgite studied by batch, XPS, and EXAFS techniques.

PubMed

Fan, Q H; Tan, X L; Li, J X; Wang, X K; Wu, W S; Montavon, G

2009-08-01

The effects of pH, ionic strength, and temperature on sorption of Eu(III) on attapulgite were investigated in the presence and absence of fulvic acid (FA) and humic acid (HA). The results indicated that the sorption of Eu(III) on attapulgite was strongly dependent on pH and ionic strength, and independent of temperature. In the presence of FA/HA, Eu(III) sorption was enhanced at pH < 4, decreased at pH range of 4-6, and then increased again at pH > 7. The X-ray photoelectron spectroscopy (XPS) analysis suggested that the sorption of Eu(III) might be expressed as is identical to X3Eu0, is identical to S(w)OHEu3+, and is identical to SOEu-OOC-/HA in the ternary Eu/HN/attapulgite system. The extended X-ray absorption fine structure (EXAFS) analysis of Eu-HA complexes indicated that the distances of d(Eu-O) decreased from 2.415 to 2.360 angstroms with increasing pH from 1.76 to 9.50, whereas the coordination number (N) decreased from approximately 9.94 to approximately 8.56. Different complexation species were also found for the different addition sequences of HA and Eu(III) to attapulgite suspension. The results are important to understand the influence of humic substances on Eu(III) behavior in the natural environment.

Microwave-Accelerated Surface Modification of Plasmonic Gold Thin Films with Self-Assembled Monolayers of Alkanethiols

PubMed Central

Grell, Tsehai A.J.; Alabanza, Anginelle M.; Gaskell, Karen; Aslan, Kadir

2013-01-01

A rapid surface modification technique for the formation of self-assembled monolayers (SAMs) of alkanethiols on gold thin films using microwave heating in less than 10 min is reported. In this regard, SAMs of two model alkanethiols, 11-mercaptoundecanoic acid (11-MUDA, to generate a hydrophilic surface) and undecanethiol (UDET, a hydrophobic surface), were successfully formed on gold thin films using selective microwave heating in 1) a semi-continuous and 2) a continuous fashion and at room temperature (24 hours, control experiment, no microwave heating). The formation of SAMs of 11-MUDA and UDET were confirmed by contact angle measurements, Fourier–transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The contact angles for water on SAMs formed by the selective microwave heating and conventional room temperature incubation technique (24 hours) were measured to be similar for 11-MUDA and UDET. FT-IR spectroscopy results confirmed that the internal structure of SAMs prepared using both microwave heating and at room temperature were similar. XPS results revealed that the organic and sulfate contaminants found on bare gold thin films were replaced by SAMs after the surface modification process was carried out using both microwave heating and at room temperature. PMID:24083414

Warhead Confirmation: A Follow-on to New START

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacArthur, Duncan W.

This presentation's slides are comprised of the following: Warhead Confirmation: A Follow-on to New START; What May Change?; Generic Arms Reduction Treaty; Challenges; Dismantlement and Warhead Confirmation; Confirmation Approaches; Certification; Information Barriers (IBs); The Fissile Material Transparency Technology Demonstration (FMTTD); More Recent Implementations; The Monitor’s View; Authentication; Authentication Options; Authentication in Phases; and Future Treaties.

Theory-led confirmation bias and experimental persona

NASA Astrophysics Data System (ADS)

Allen, Michael

2011-04-01

Questionnaire and interview findings from a survey of three Year 8 (ages 12-13 years) science practical lessons (n = 52) demonstrate how pupils' data collection and inference making were sometimes biased by desires to confirm a personal theory. A variety of behaviours are described where learners knowingly rejected anomalies, manipulated apparatus, invented results or carried out other improper operations to either collect data which they believed were scientifically correct, or achieve social conformity. It is proposed that confirmation bias was a consequence of the degree to which individuals were laden by theory, and driven by this, experimenters assumed one of three different personas: becoming right answer confirmers; good scientists; or indifferent spectators. These personas have parallels with historical instances of scientific behaviour. Implications of a continued teacher-tolerance of pupil confirmation bias include the promotion of unscientific experimenting, and the persistence of unchallenged science misconceptions. Solutions are offered in the way of practical strategies that might reduce experimenters' theory-ladeness.

Confirmation of nasogastric tube position by pH testing.

PubMed

Taylor, S J; Clemente, R

2005-10-01

In 2004, the Medicines and Healthcare products Regulatory Agency (MHRA) advised that nasogastric (NG) tube position should be confirmed using pH strips or paper. However, gastric pH is raised by the use of H2-blockers and proton-pump inhibitors (PPIs) potentially producing false negative pH tests resulting in delayed feeding. In addition, colorimetric differentiation using pH strips may be more prone to bias and inaccuracy than direct pH measurements largely used to establish the threshold. To quantify this problem a 1 day survey of all the patients requiring NG and nasointestinal (NI) feeding was undertaken, to establish the numbers of patients receiving H2-Blockers or PPIs, with or without a safe swallow and the methods currently being used to confirm tube positioning. A second observational study was performed to establish the accuracy of six pH strips available to NHS trusts against four unlabelled pH solutions. Forty-two per cent of patients receiving NG feeding were on H2-blockers or PPIs, including 13% who had a safe swallow for acidic drinks that could be subsequently aspirated to confirm position. In the second study 'testers' correctly identified pH's 3, 4, 5 and 6 with Mackery-Nagel 0-6, BDH 0-6 and 0-14 strips but overestimated pH 4 as pH 5 with Johnson 0-11 paper, underestimated pH 6 as pH 5 with Pehanon 0-12 paper and with Litmus classified pH 3-5 as acid (all), but half also classified pH 6 as acid. Theoretically 29% of NG tube positions could not be confirmed by pH testing because of the usage of PPIs or H2-blockers and lack of swallow. Some pH strips are either inaccurate or their result misinterpreted by staff. Large surveys and trials of the actual efficacy and accuracy of pH testing are required.

Experimental confirmation of the atomic force microscope cantilever stiffness tilt correction

NASA Astrophysics Data System (ADS)

Gates, Richard S.

2017-12-01

The tilt angle (angle of repose) of an AFM cantilever relative to the surface it is interrogating affects the effective stiffness of the cantilever as it analyzes the surface. For typical AFMs and cantilevers that incline from 10° to 15° tilt, this is thought to be a 3%-7% stiffness increase correction. While the theoretical geometric analysis of this effect may have reached a consensus that it varies with cos-2 θ, there is very little experimental evidence to confirm this using AFM cantilevers. Recently, the laser Doppler vibrometry thermal calibration method utilized at NIST has demonstrated sufficient stiffness calibration accuracy, and precision to allow a definitive experimental confirmation of the particular trigonometric form of this tilt effect using a commercial microfabricated AFM cantilever specially modified to allow strongly tilted (up to 15°) effective cantilever stiffness measurements.

Scrapping of student bursaries confirmed.

PubMed

Longhurst, Chris

2016-07-27

Student bursaries for nurses will be scrapped from next year, the government has confirmed. Undergraduate nursing and midwifery students in England will now face tuition fees and student loans from August 2017.

Feminizing Genital Gender-Confirmation Surgery.

PubMed

Hadj-Moussa, Miriam; Ohl, Dana A; Kuzon, William M

2018-02-14

For many patients with gender dysphoria, gender-confirmation surgery (GCS) helps align their physical characteristics with their gender identity and is a fundamental element of comprehensive treatment. This article is the 2nd in a 3-part series about the treatment of gender dysphoria. Non-operative management was covered in part 1. This section begins broadly by reviewing surgical eligibility criteria, benefits of GCS, and factors associated with regret for transgender men and women. Then, the scope narrows to focus on aspects of feminizing genital GCS, including a discussion of vaginoplasty techniques, complications, and sexual function outcomes. Part 3 features operative considerations for masculinizing genital GCS. To summarize the World Professional Association for Transgender Health's (WPATH) surgical eligibility criteria and describe how patients with gender dysphoria benefit from GCS, provide an overview of genital and non-genital feminizing gender-confirmation procedures, and review vaginoplasty techniques, preoperative considerations, complications, and outcomes. A review of relevant literature through April 2017 was performed using PubMed. Review of literature related to surgical eligibility criteria for GCS, benefits of GCS, and surgical considerations for feminizing genitoplasty. Most transgender men and women who satisfy WPATH eligibility criteria experience improved quality of life, overall happiness, and sexual function after GCS; regret is rare. Penile inversion vaginoplasty is the preferred technique for feminizing genital GCS according to most surgeons, including the authors whose surgical technique is described. Intestinal vaginoplasty is reserved for certain scenarios. After vaginoplasty most patients report overall high satisfaction with their sexual function even when complications occur, because most are minor and easily treatable. GCS alleviates gender dysphoria for appropriately selected transgender men and women. Preoperative

Selective enrichment of volatiles confirmed

NASA Astrophysics Data System (ADS)

de Pater, Imke

2018-04-01

Hydrogen sulfide gas is detected above Uranus's main cloud deck, confirming the prevalence of H2S ice particles as the main cloud component and a strongly unbalanced nitrogen/sulfur ratio in the planet's deep atmosphere.

Selective enrichment of volatiles confirmed

NASA Astrophysics Data System (ADS)

de Pater, Imke

2018-05-01

Hydrogen sulfide gas is detected above Uranus's main cloud deck, confirming the prevalence of H2S ice particles as the main cloud component and a strongly unbalanced nitrogen/sulfur ratio in the planet's deep atmosphere.

XPS study of the effect of hydrocarbon contamination on polytetrafluoroethylene (teflon) exposed to atomic oxygen

NASA Technical Reports Server (NTRS)

Golub, Morton A.; Wydeven, Theodore; Cormia, Robert D.

1991-01-01

The presence of hydrocarbon contamination on the surface of polytetrafluoroethylene (PTFE) markedly affects the oxygen uptake, and hence the wettability, of this polymer when exposed to an oxygen plasma. As revealed by X-ray photoelectron spectroscopy (XPS) analysis, the oxygen-to-carbon ratio (O/C) for such a polymer can increase sharply, and correspondingly the fluorine-to-carbon ratio (F/C) can decrease sharply, at very short exposure times; at longer times, however, such changes in the O/C and F/C ratios reverse direction, and these ratios then assume values similar to those of the unexposed PTFE. The greater the extent of hydrocarbon contamination in the PTFE, the larger are the amplitudes of the 'spikes' in the O/C- and F/C-exposure time plots. In contrast, a pristine PTFE experiences a very small, monotonic increase of surface oxidation or O/C ratio with time of exposure to oxygen atoms, while the F/C ratio is virtually unchanged from that of the unexposed polymer (2.0). Unless the presence of adventitious hydrocarbon is taken into account, anomalous surface properties relating to polymer adhesion may be improperly ascribed to PTFE exposed to an oxygen plasma.

Novel applications of X-ray photoelectron spectroscopy on unsupported nanoparticles

NASA Astrophysics Data System (ADS)

Kostko, Oleg; Xu, Bo; Jacobs, Michael I.; Ahmed, Musahid

X-ray photoelectron spectroscopy (XPS) is a powerful technique for chemical analysis of surfaces. We will present novel results of XPS on unsupported, gas-phase nanoparticles using a velocity-map imaging (VMI) spectrometer. This technique allows for probes of both the surfaces of nanoparticles via XPS as well as their interiors via near edge X-ray absorption fine structure (NEXAFS) spectroscopy. A recent application of this technique has confirmed that arginine's guanidinium group exists in a protonated state even in strongly basic solution. Moreover, the core-level photoelectron spectroscopy can provide information on the effective attenuation length (EAL) of low kinetic energy electrons. This contradictory value is important for determining the probing depth of XPS and in photolithography. A new method for determining EALs will be presented.

Atomic force measurements of 16-mercaptohexadecanoic acid and its salt with CH 3, OH, and CONHCH 3 functionalized self-assembled monolayers

NASA Astrophysics Data System (ADS)

Morales-Cruz, Angel L.; Tremont, Rolando; Martínez, Ramón; Romañach, Rodolfo; Cabrera, Carlos R.

2005-03-01

Chemical and mechanical properties of different compounds can be elucidated by measuring fundamental forces such as adhesion, attraction and repulsion, between modified surfaces by means of atomic force microscopy (AFM) in force mode calibration. This work presents a combination of AFM, self-assembled monolayers (SAMs), and crystallization techniques to study the forces of interaction between excipients and active ingredients used in pharmaceutical formulations. SAMs of 16-mercaptohexadecanoate, which represent magnesium stereate, were used to modify the probe tip, whereas CH3-, OH- and CONHCH3-functional SAMs were formed on a gold-coated mica substrate, and used as examples of the surfaces of lactose and theophylline. The crystals of lactose and theophylline were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The modification of gold surfaces with 16-mercaptohexadecanoate, 10-mercapto-1-decanol (OH-functional SAM), 1-decanethiol (CH3-functional) and N-methyl-11-mercaptoundecanamide (CONHCH3-functional SAM) was studied by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and Fourier transform-infrared spectroscopy (FT-IR) in specular reflectance mode. XPS and AES results of the modified surfaces showed the presence of sulfur binding, and kinetic energies that correspond to the presence of 10-mercapto-1-decanol, 1-decanethiol, N-methyl-11-mercaptoundecanamide and the salt of 16-mercaptohexadecanoic acid. The absorption bands in the IR spectra further confirm the modification of the gold-coated substrates with these compounds. Force versus distance measurements were performed between the modified tip and the modified gold-coated mica substrates. The mean adhesion forces between the COO-Ca2+ functionalized tip and the CH3-, OH-, and CONHCH3-modified substrates were determined to be 4.5, 8.9 and 6.3 nN, respectively. The magnitude of the adhesion force (ion-dipole) interaction between the modified tip and

Ultrasound influence on the activation step before electroless coating.

PubMed

Touyeras, F; Hihn, J Y; Delalande, S; Viennet, R; Doche, M L

2003-10-01

This paper is devoted to the electroless plating of non-conductive substrates under ultrasound at 530 kHz. The ultrasonic irradiation is applied to the activation and to the plating steps. Effects are measured by following the final copper thickness obtained in 1 h of plating time, easily correlated to the average plating rate. It appears that ultrasound has a strong influence on the plating rates enhancement, and assumptions can be made that this increase could be linked to the catalyst cleaning. This is confirmed by XPS measurements.

Opinion Dynamics with Confirmation Bias

PubMed Central

Allahverdyan, Armen E.; Galstyan, Aram

2014-01-01

Background Confirmation bias is the tendency to acquire or evaluate new information in a way that is consistent with one's preexisting beliefs. It is omnipresent in psychology, economics, and even scientific practices. Prior theoretical research of this phenomenon has mainly focused on its economic implications possibly missing its potential connections with broader notions of cognitive science. Methodology/Principal Findings We formulate a (non-Bayesian) model for revising subjective probabilistic opinion of a confirmationally-biased agent in the light of a persuasive opinion. The revision rule ensures that the agent does not react to persuasion that is either far from his current opinion or coincides with it. We demonstrate that the model accounts for the basic phenomenology of the social judgment theory, and allows to study various phenomena such as cognitive dissonance and boomerang effect. The model also displays the order of presentation effect–when consecutively exposed to two opinions, the preference is given to the last opinion (recency) or the first opinion (primacy) –and relates recency to confirmation bias. Finally, we study the model in the case of repeated persuasion and analyze its convergence properties. Conclusions The standard Bayesian approach to probabilistic opinion revision is inadequate for describing the observed phenomenology of persuasion process. The simple non-Bayesian model proposed here does agree with this phenomenology and is capable of reproducing a spectrum of effects observed in psychology: primacy-recency phenomenon, boomerang effect and cognitive dissonance. We point out several limitations of the model that should motivate its future development. PMID:25007078

On rules of induction and the raven paradox in Bayesian confirmation theory

NASA Astrophysics Data System (ADS)

Afshar, H. M.; Sunehag, P.

2014-12-01

Confirmation theory is studying how one can confirm a universal statement like "All ravens are black". Early authors discussed how one's degree of belief in such a statement should change with new evidence and suggested various rules of induction. Nicod's Condition (NC) says that the claim that all F are G is supported by observing a previously unseen object that is both F and G. Hempel pointed out that NC implies the paradoxical conclusion that observing a white sock supports that all ravens are black. In our time, confirmation is studied by using subjective conditional probability as degrees of belief with Kolmogorov's axioms as the main rules of induction. The old rules and problems of induction are, however, still studied within the probabilistic framework. We consider a setting where the number of individuals having a particular property is given and find that NC can contradict a simpler principle, namely projectability (PJ) which says that if we observe an object with property ψ then other objects are also more likely to have property ψ. We find that intuition can side with either one depending on the situation. We suggest that a more appropriate formalization of the intuition behind NC is the weaker principle of reasoning by analogy (RA). RA says that if we see an object that is F and G and we know that another object is F, then it is more likely to also be G. Projectability might still be considered valid for relatively uninformed a priori beliefs. If one decides that a principle like projectability is valid for confirmation in an uninformed situation, it provides a test that an a priori distribution must satisfy. Hence, decreasing the arbitrariness of the choice of measure. Further, by considering background knowledge saying only how many ravens there are in the world we conclude that if someone accepts the projectability principle, an agent will not increment the belief that all ravens are black when having observed a white sock. Most Bayesian

Corrosion product layers on magnesium alloys AZ31 and AZ61: Surface chemistry and protective ability

NASA Astrophysics Data System (ADS)

Feliu, S.; Llorente, I.

2015-08-01

This paper studies the chemical composition of the corrosion product layers formed on magnesium alloys AZ31 and AZ61 following immersion in 0.6 M NaCl, with a view to better understanding their protective action. Relative differences in the chemical nature of the layers were quantified by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) and low-angle X-ray diffraction (XRD). Corrosion behavior was investigated by Electrochemical Impedance Spectroscopy (EIS) and hydrogen evolution measurement. An inhibitive effect from the corrosion product layers was observed from EIS, principally in the case of AZ31, as confirmed by hydrogen evolution tests. A link was found between carbonate enrichment observed by XPS in the surface of the corrosion product layer, concomitant with the increase in the protective properties observed by EIS.

Ferrocene-functionalized graphene electrode for biosensing applications.

PubMed

Rabti, Amal; Mayorga-Martinez, Carmen C; Baptista-Pires, Luis; Raouafi, Noureddine; Merkoçi, Arben

2016-07-05

A novel ferrocene-functionalized reduced graphene oxide (rGO)-based electrode is proposed. It was fabricated by the drop casting of ferrocene-functionalized graphene onto polyester substrate as the working electrode integrated within screen-printed reference and counter electrodes. The ferrocene-functionalized rGO has been fully characterized using FTIR, XPS, contact angle measurements, SEM and TEM microscopy, and cyclic voltammetry. The XPS and EDX analysis showed the presence of Fe element related to the introduced ferrocene groups, which is confirmed by a clear CV signal at ca. 0.25 V vs. Ag/AgCl (0.1 KCl). Mediated redox catalysis of H2O2 and bio-functionalization with glucose oxidase for glucose detection were achieved by the bioelectrode providing a proof for potential biosensing applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Atomic layer deposition of Cu( i ) oxide films using Cu( ii ) bis(dimethylamino-2-propoxide) and water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avila, J. R.; Peters, A. W.; Li, Zhanyong

2017-01-01

To grow fIlms of Cu2O, bis-(dimethylamino-2-propoxide)Cu(II), or Cu(dmap), is used as an atomic layer deposition precursor using only water vapor as a co-reactant. Between 110 and 175 °C, a growth rate of 0.12 ± 0.02 Å per cycle was measured using an in situ quartz crystal microbalance (QCM). X-ray photoelectron spectroscopy (XPS) confirms the growth of metal– oxide films featuring Cu(I).

Senate Confirmation Hearing IG

NASA Image and Video Library

2009-10-14

Paul K. Martin, nominee for Inspector General at NASA, far right, answers questions during his confirmation hearing in front of the Senate Committee on Commerce, Science and Transportation, Thursday, Oct. 15, 2009, on Capitol Hill in Washington. Looking on are Dr. Elizabeth M. Robinson, nominee for Chief Financial Officer for NASA, center, and Dr. Patrick Gallagher, nominee to be Assistant Secretary of the Transportation Security Administration at the U.S. Department of Commerce. Photo Credit: (NASA/Paul E. Alers)

Rhenium in seawater - Confirmation of generally conservative behavior

NASA Technical Reports Server (NTRS)

Anbar, A. D.; Creaser, R. A.; Papanastassiou, D. A.; Wasserburg, G. J.

1992-01-01

A depth profile of the concentration of Re was measured in the Pacific Ocean using a technique developed for the clean chemical separation and the precise measurement of Re by isotope dilution and negative thermal ionization mass spectrometry (ID-NTIMS). We obtain a narrow range for Re from 7.20 +/- 0.03 to 7.38 +/- 0.03 ng/kg for depths between 45 m and 4700 m. This demonstrates that Re is relatively well mixed throughout the water column and confirms the theoretical prediction that the behavior of Re in the oceans is conservative. When examined in detail, both salinity and the concentration of Re increase by approximately 1.5 percent between 400 and 4700 m, a correlation consistent with conservative behavior. However, Re appears to be depleted relative to salinity by 1.0-1.5 percent at 100 m, and enriched by approximately 4 percent at the surface. These observations suggest a minor level of Re scavenging in near surface waters, and an input of Re to the ocean surface. This work demonstrates the utility of geochemical investigations of certain trace elements not previously been amenable to detailed study.

Production of sp3 hybridization by swift heavy ion irradiation of HOPG

NASA Astrophysics Data System (ADS)

Zeng, J.; Zhai, P. F.; Liu, J.; Yao, H. J.; Duan, J. L.; Hou, M. D.; Sun, Y. M.; Li, G. P.

2013-07-01

Highly oriented pyrolytic graphite (HOPG) samples were irradiated by swift heavy ions (86Kr, 209Bi and 238U) with the fluence of 1011-1013 ions/cm2 at room temperature. The production of sp3 hybridization by the irradiation process has been confirmed directly by X-ray photoelectron spectroscopy (XPS). In this work, both irradiated and pristine HOPG samples were investigated by XPS and Raman spectroscopy. The existence of sp3 component is confirmed on the surface of the irradiated HOPG samples. XPS result shows that the acreage ratio Isp3/Isp2 increases with the ion fluence and saturates at a higher value of irradiation. It is found that the amount of hybridization (Isp3/Isp2) strongly depends on the electronic energy loss in the sample. Raman spectra of the irradiated samples show the increasing of acreage ratio ID/IG with the ion fluence, which indicates the change of the atomic structure and the phase transition from sp2 to sp3.

Shana Dale Senate Confirmation Hearing

NASA Image and Video Library

2005-11-01

Shana Dale testifies at her confirmation hearing before the Senate Committee on Commerce, Science, and Transportation, Nov. 1, 2005, on Capitol Hill in Washington. Dale was nominated by President Bush to be the deputy administrator of the National Aeronautics and Space Administration (NASA). Photo Credit: (NASA/Bill Ingalls)

Model confirmation in climate economics

PubMed Central

Millner, Antony; McDermott, Thomas K. J.

2016-01-01

Benefit–cost integrated assessment models (BC-IAMs) inform climate policy debates by quantifying the trade-offs between alternative greenhouse gas abatement options. They achieve this by coupling simplified models of the climate system to models of the global economy and the costs and benefits of climate policy. Although these models have provided valuable qualitative insights into the sensitivity of policy trade-offs to different ethical and empirical assumptions, they are increasingly being used to inform the selection of policies in the real world. To the extent that BC-IAMs are used as inputs to policy selection, our confidence in their quantitative outputs must depend on the empirical validity of their modeling assumptions. We have a degree of confidence in climate models both because they have been tested on historical data in hindcasting experiments and because the physical principles they are based on have been empirically confirmed in closely related applications. By contrast, the economic components of BC-IAMs often rely on untestable scenarios, or on structural models that are comparatively untested on relevant time scales. Where possible, an approach to model confirmation similar to that used in climate science could help to build confidence in the economic components of BC-IAMs, or focus attention on which components might need refinement for policy applications. We illustrate the potential benefits of model confirmation exercises by performing a long-run hindcasting experiment with one of the leading BC-IAMs. We show that its model of long-run economic growth—one of its most important economic components—had questionable predictive power over the 20th century. PMID:27432964

Chemical and morphological characterization of TSP and PM2.5 by SEM-EDS, XPS and XRD collected in the metropolitan area of Monterrey, Mexico

NASA Astrophysics Data System (ADS)

González, Lucy T.; Rodríguez, F. E. Longoria; Sánchez-Domínguez, M.; Leyva-Porras, C.; Silva-Vidaurri, L. G.; Acuna-Askar, Karim; Kharisov, B. I.; Villarreal Chiu, J. F.; Alfaro Barbosa, J. M.

2016-10-01

Total suspended particles (TSP) and particles smaller than 2.5 μm (PM2.5) were collected at four sites in the metropolitan area of Monterrey (MAM) in Mexico. The samples were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM). In order to determine the possible sources of emissions of atmospheric particulate matter, a principal component analysis (PCA) was performed. The XRD results showed that the major crystalline compounds found in the TPS were CaCO3 and SiO2; while in the PM2.5 CaSO4 was found. The XPS analysis showed that the main elements found on the surface of the particles were C, O, Si, Ca, S, and N. The deconvolution carried out on the high-resolution spectra for C1s, S2p and N1s, showed that the aromatics, sulfates and pyrrolic-amides were the main groups contributing to the signal of these elements, respectively. The C-rich particles presented a spherical morphology, while the Ca- and Si-based particles mostly showed a prismatic shape. The PCA analysis together with the results obtained from the characterization techniques, suggested that the main contributors to the CaCO3 particles collected in the PM were most probably produced and emitted into the atmosphere by local construction industries and exploitation of rich-deposits of calcite. Meanwhile, the SiO2 found in the MAM originated from the suspension of geological material abundant in the region, and the carbon particles were mainly produced by the combustion of fossil fuels.

Confirmation of the Factor Structure and Measurement Invariance of the Children's Scale of Hostility and Aggression: Reactive/Proactive in Clinic-Referred Children With and Without Autism Spectrum Disorder.

PubMed

Farmer, Cristan A; Kaat, Aaron J; Mazurek, Micah O; Lainhart, Janet E; DeWitt, Mary Beth; Cook, Edwin H; Butter, Eric M; Aman, Michael G

2016-02-01

The measurement of aggression in its different forms (e.g., physical and verbal) and functions (e.g., impulsive and instrumental) is given little attention in subjects with developmental disabilities (DD). In this study, we confirm the factor structure of the Children's Scale for Hostility and Aggression: Reactive/Proactive (C-SHARP) and demonstrate measurement invariance (consistent performance across clinical groups) between clinic-referred groups with and without autism spectrum disorder (ASD). We also provide evidence of the construct validity of the C-SHARP. Caregivers provided C-SHARP, Child Behavior Checklist (CBCL), and Proactive/Reactive Rating Scale (PRRS) ratings for 644 children, adolescents, and young adults 2-21 years of age. Five types of measurement invariance were evaluated within a confirmatory factor analytic framework. Associations among the C-SHARP, CBCL, and PRRS were explored. The factor structure of the C-SHARP had a good fit to the data from both groups, and strict measurement invariance between ASD and non-ASD groups was demonstrated (i.e., equivalent structure, factor loadings, item intercepts and residuals, and latent variance/covariance between groups). The C-SHARP Problem Scale was more strongly associated with CBCL Externalizing than with CBCL Internalizing, supporting its construct validity. Subjects classified with the PRRS as both Reactive and Proactive had significantly higher C-SHARP Proactive Scores than those classified as Reactive only, who were rated significantly higher than those classified by the PRRS as Neither Reactive nor Proactive. A similar pattern was observed for the C-SHARP Reactive Score. This study provided evidence of the validity of the C-SHARP through confirmation of its factor structure and its relationship with more established scales. The demonstration of measurement invariance demonstrates that differences in C-SHARP factor scores were the result of differences in the construct rather than to error or

The Quality and Effectiveness of Confirmation Classes in Finland

ERIC Educational Resources Information Center

Niemela, Kati

2006-01-01

Every year some 90% of 15-year-olds in Finland attend confirmation classes in the Evangelical Lutheran Church of Finland, which is greater than the percentage of that age group belonging to the Church. What is behind the popularity of Finnish confirmation classes? This article scrutinizes the quality and effectiveness of confirmation classes.…

Experimental confirmation of long-memory correlations in star-wander data.

PubMed

Zunino, Luciano; Gulich, Damián; Funes, Gustavo; Ziad, Aziz

2014-07-01

In this Letter we have analyzed the temporal correlations of the angle-of-arrival fluctuations of stellar images. Experimentally measured data were carefully examined by implementing multifractal detrended fluctuation analysis. This algorithm is able to discriminate the presence of fractal and multifractal structures in recorded time sequences. We have confirmed that turbulence-degraded stellar wavefronts are compatible with a long-memory correlated monofractal process. This experimental result is quite significant for the accurate comprehension and modeling of the atmospheric turbulence effects on the stellar images. It can also be of great utility within the adaptive optics field.

Surface and bulk crystallization of amorphous solid water films: Confirmation of “top-down” crystallization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Chunqing; Smith, R. Scott; Kay, Bruce D.

2016-01-11

Here, the crystallization kinetics of nanoscale amorphous solid water (ASW) films are investigated using temperature-programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS). TPD measurements are used to probe surface crystallization and RAIRS measurements are used to probe bulk crystallization. Isothermal TPD results show that surface crystallization is independent of the film thickness (from 100 to 1000 ML). Conversely, the RAIRS measurements show that the bulk crystallization time increases linearly with increasing film thickness. These results suggest that nucleation and crystallization begin at the ASW/vacuum interface and then the crystallization growth front propagates linearly into the bulk. This mechanism wasmore » confirmed by selective placement of an isotopic layer (5% D 2O in H 2O) at various positions in an ASW (H 2O) film. In this case, the closer the isotopic layer was to the vacuum interface, the earlier the isotopic layer crystallized. These experiments provide direct evidence to confirm that ASW crystallization in vacuum proceeds by a “top-down” crystallization mechanism.« less

Senate Confirmation Hearing CFO

NASA Image and Video Library

2009-10-14

Dr. Elizabeth M. Robinson, nominee for Chief Financial Officer for NASA, center, answers questions during her confirmation hearing in front of the Senate Committee on Commerce, Science and Transportation, Thursday, Oct. 15, 2009, on Capitol Hill in Washington. Robinson is flanked by Dr. Patrick Gallagher, nominee to be Assistant Secretary of the Transportation Security Administration at the U.S. Department of Commerce, far left, and Paul K. Martin, nominee to be Inspector General at NASA. Photo Credit: (NASA/Paul E. Alers)

Graham confirmed as OSTP Head

NASA Astrophysics Data System (ADS)

William R. Graham was confirmed by the Senate on October 1, 1986, as the science advisor to President Ronald Reagan and head of the Office of Science and Technology Policy (OSTP). Formerly the deputy administrator of the National Aeronautics and Space Administration (NASA), Graham started his new post on October 6.

Cardiac MRI-confirmed mesalamine-induced myocarditis

PubMed Central

Baker, William L; Saulsberry, Whitney J; Elliott, Kaitlyn; Parker, Matthew W

2015-01-01

A 38-year-old Caucasian man with a medical history significant for inflammatory bowel disease (IBD) and mesalamine use presented to the emergency department with stabbing, pleuritic, substernal chest pain over the previous 2 days. Findings of leucocytosis, elevated cardiac enzymes and inflammatory markers, T-wave or ST-segment abnormalities and left ventricular systolic dysfunction suggested mesalamine-induced myocarditis. However, a cardiac MRI confirmed the diagnosis. Signs and symptoms improved within days of withdrawal of mesalamine, and initiation of corticosteroids and follow-up studies within the next year were unremarkable. Importantly, the diagnosis of mesalamine-induced myocarditis confirmed via cardiac MRI is a step rarely performed in published cases. PMID:26341161

Cardiac MRI-confirmed mesalamine-induced myocarditis.

PubMed

Baker, William L; Saulsberry, Whitney J; Elliott, Kaitlyn; Parker, Matthew W

2015-09-04

A 38-year-old Caucasian man with a medical history significant for inflammatory bowel disease (IBD) and mesalamine use presented to the emergency department with stabbing, pleuritic, substernal chest pain over the previous 2 days. Findings of leucocytosis, elevated cardiac enzymes and inflammatory markers, T-wave or ST-segment abnormalities and left ventricular systolic dysfunction suggested mesalamine-induced myocarditis. However, a cardiac MRI confirmed the diagnosis. Signs and symptoms improved within days of withdrawal of mesalamine, and initiation of corticosteroids and follow-up studies within the next year were unremarkable. Importantly, the diagnosis of mesalamine-induced myocarditis confirmed via cardiac MRI is a step rarely performed in published cases. 2015 BMJ Publishing Group Ltd.

Electronic structure study of wide band gap magnetic semiconductor (La0.6Pr0.4)0.65Ca0.35MnO3 nanocrystals in paramagnetic and ferromagnetic phases

NASA Astrophysics Data System (ADS)

Dwivedi, G. D.; Joshi, Amish G.; Kumar, Shiv; Chou, H.; Yang, K. S.; Jhong, D. J.; Chan, W. L.; Ghosh, A. K.; Chatterjee, Sandip

2016-04-01

X-ray circular magnetic dichroism (XMCD), X-ray photoemission spectroscopy (XPS), and ultraviolet photoemission spectroscopy (UPS) techniques were used to study the electronic structure of nanocrystalline (La0.6Pr0.4)0.65Ca0.35MnO3 near Fermi-level. XMCD results indicate that Mn3+ and Mn4+ spins are aligned parallel to each other at 20 K. The low M-H hysteresis curve measured at 5 K confirms ferromagnetic ordering in the (La0.6Pr0.4)0.65Ca0.35MnO3 system. The low temperature valence band XPS indicates that coupling between Mn3d and O2p is enhanced and the electronic states near Fermi-level have been suppressed below TC. The valence band UPS also confirms the suppression of electronic states near Fermi-level below Curie temperature. UPS near Fermi-edge shows that the electronic states are almost absent below 0.5 eV (at 300 K) and 1 eV (at 115 K). This absence clearly demonstrates the existence of a wide band-gap in the system since, for hole-doped semiconductors, the Fermi-level resides just above the valence band maximum.

Synergistic effects of Mo and F doping on the quality factor of ZnO thin films prepared by a fully automated home-made nebulizer spray technique

NASA Astrophysics Data System (ADS)

Ravichandran, K.; Dineshbabu, N.; Arun, T.; Manivasaham, A.; Sindhuja, E.

2017-01-01

Transparent conducting oxide films of undoped, Mo doped, Mo + F co-doped ZnO were deposited using a facile homemade nebulizer spray pyrolysis technique. The effects of Mo and F doping on the structural, optical, electrical and surface morphological properties were investigated using XRD, UV-vis-NIR spectroscopy, I-V and Hall probe techniques, FESEM and AFM, and XPS, respectively. The XRD analysis confirms that all the films are well crystallized with hexagonal wurtzite structure. All the synthesized samples exhibit high transmittance (above 85%) in the visible region. The current-voltage (I-V) characteristics show the ohmic conduction nature of the films. The Hall probe measurements show that the synergistic effects of Mo and F doping cause desirable improvements in the quality factor of the ZnO films. A minimum resistivity of 5.12 × 10-3 Ω cm with remarkably higher values of mobility and carrier concentration is achieved for Mo (2 at.%) + F (15 at.%) co-doped ZnO films. A considerable variation in the intensity of deep level emission caused by Mo and F doping is observed in the photoluminescence (PL) studies. The presence of the constituent elements in the samples is confirmed by XPS analysis.

Confirming expectations in asymmetric and symmetric social hypothesis testing.

PubMed

Rusconi, Patrice; Sacchi, Simona; Toscano, Armando; Cherubini, Paolo

2012-01-01

This article examines individuals' expectations in a social hypothesis testing task. Participants selected questions from a list to investigate the presence of personality traits in a target individual. They also identified the responses that they expected to receive and the likelihood of the expected responses. The results of two studies indicated that when people asked questions inquiring about the hypothesized traits that did not entail strong a priori beliefs, they expected to find evidence confirming the hypothesis under investigation. These confirming expectations were more pronounced for symmetric questions, in which the diagnosticity and frequency of the expected evidence did not conflict. When the search for information was asymmetric, confirming expectations were diminished, likely as a consequence of either the rareness or low diagnosticity of the hypothesis-confirming outcome. We also discuss the implications of these findings for confirmation bias.

Conservation of artists' acrylic emulsion paints: XPS, NEXAFS and ATR-FTIR studies of wet cleaning methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willneff, E. A.; Ormsby, B. A.; Stevens, J. S.

Works of art prepared with acrylic emulsion paints became commercially available in the 1960s. It is increasingly necessary to undertake and optimise cleaning and preventative conservation treatments to ensure their longevity. Model artists' acrylic paint films covered with artificial soiling were thus prepared on a canvas support and exposed to a variety of wet cleaning treatments based on aqueous or hydrocarbon solvent systems. This included some with additives such as chelating agents and/or surfactants, and microemulsion systems made specifically for conservation practice. The impact of cleaning (soiling removal) on the paint film surface was examined visually and correlated with resultsmore » of attenuated total reflection Fourier transform infrared, XPS and near-edge X-ray absorption fine structure analyses – three spectroscopic techniques with increasing surface sensitivity ranging from approximately $-$ 1000, 10 and 5 nm, respectively. Visual analysis established the relative cleaning efficacy of the wet cleaning treatments in line with previous results. X-ray spectroscopy analysis provided significant additional findings, including evidence for (i) surfactant extraction following aqueous swabbing, (ii) modifications to pigment following cleaning and (iii) cleaning system residues.« less

Conservation of artists' acrylic emulsion paints: XPS, NEXAFS and ATR-FTIR studies of wet cleaning methods

DOE PAGES

Willneff, E. A.; Ormsby, B. A.; Stevens, J. S.; ...

2014-02-17

Works of art prepared with acrylic emulsion paints became commercially available in the 1960s. It is increasingly necessary to undertake and optimise cleaning and preventative conservation treatments to ensure their longevity. Model artists' acrylic paint films covered with artificial soiling were thus prepared on a canvas support and exposed to a variety of wet cleaning treatments based on aqueous or hydrocarbon solvent systems. This included some with additives such as chelating agents and/or surfactants, and microemulsion systems made specifically for conservation practice. The impact of cleaning (soiling removal) on the paint film surface was examined visually and correlated with resultsmore » of attenuated total reflection Fourier transform infrared, XPS and near-edge X-ray absorption fine structure analyses – three spectroscopic techniques with increasing surface sensitivity ranging from approximately $-$ 1000, 10 and 5 nm, respectively. Visual analysis established the relative cleaning efficacy of the wet cleaning treatments in line with previous results. X-ray spectroscopy analysis provided significant additional findings, including evidence for (i) surfactant extraction following aqueous swabbing, (ii) modifications to pigment following cleaning and (iii) cleaning system residues.« less

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

NASA Technical Reports Server (NTRS)

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.

Stereotype confirmation concerns predict dropout from cognitive behavioral therapy for social anxiety disorder.

PubMed

Johnson, Suzanne; Price, Matthew; Mehta, Natasha; Anderson, Page L

2014-08-19

There are high attrition rates observed in efficacy studies for social anxiety disorder, and research has not identified consistent nor theoretically meaningful predictors of dropout. Pre-treatment symptom severity and demographic factors, such as age and gender, are sometimes predictive of dropout. The current study examines a theoretically meaningful predictor of attrition based on experiences associated with social group membership rather than differences between social group categories--fear of confirming stereotypes. This is a secondary data analysis of a randomized controlled trial comparing two cognitive behavioral treatments for social anxiety disorder: virtual reality exposure therapy and exposure group therapy. Participants (N = 74) with a primary diagnosis of social anxiety disorder who were eligible to participate in the parent study and who self-identified as either "African American" (n = 31) or "Caucasian" (n = 43) completed standardized self-report measures of stereotype confirmation concerns (SCC) and social anxiety symptoms as part of a pre-treatment assessment battery. Hierarchical logistic regression showed that greater stereotype confirmation concerns were associated with higher dropout from therapy--race, age, gender, and pre-treatment symptom severity were not. Group treatment also was associated with higher dropout. These findings urge further research on theoretically meaningful predictors of attrition and highlight the importance of addressing cultural variables, such as the experience of stereotype confirmation concerns, during treatment of social anxiety to minimize dropout from therapy.

Evaluation of the oleophilicity of different alkoxysilane modified ceramic membranes through wetting dynamic measurements

NASA Astrophysics Data System (ADS)

Gao, Nengwen; Ke, Wei; Fan, Yiqun; Xu, Nanping

2013-10-01

Wettability has been recognized as one of the most important properties of porous materials for both fundamental and practical applications. In this study, the oleophilicity of Al2O3 membranes modified by four alkoxysilanes with different length of alkyl group was investigated through oil wetting dynamic test. Fourier transform infrared spectroscopy (FTIR), thermogravimertric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were measured to confirm that ceramic membrane surfaces have been grafted with alkoxysilanes without changing the membrane morphology. A high speed video camera was used to record the spreading and imbibition process of oil on the modified membrane surface. The value of oil contact angle and its change during the wetting process were used to characterize the membrane oleophilicity. Characterization results showed that the oleophilicity of the modified membranes increased along with the increasing of the silane alkyl group. The influence of oleophilicity on the filtration performance of water-in-oil (W/O) emulsions was experimentally studied. A higher oil flux was obtained for membranes grafted with a longer alkyl group, indicating that increase oleophilicity can increase the membrane antifouling property. This work presents a valuable route to the surface oleophilicity control and testing of ceramic membranes in the filtration of non-polar organic solvents.

XPS investigations of tribolayers formed on TiN and (Ti,Re)N coatings

NASA Astrophysics Data System (ADS)

Oktay, Serkan; Kahraman, Zafer; Urgen, Mustafa; Kazmanli, Kursat

2015-02-01

TiN and (Ti,Re)N coatings were deposited on high-speed-steel substrates by a hybrid coating system composed of cathodic arc PVD and magnetron sputtering techniques. In order to keep rhenium content low (8 ± 1.9 at.%) in the coating, magnetron sputtering technique was utilized to evaporate rhenium. The (Ti,Re)N coating consisted of TiN and ReNx (x > 1.33) phases. The hardness of TiN and (Ti,Re)N were 31 GPa and 29 GPa (± 2 GPa), respectively. Tribological behaviors of the samples were tested against Al2O3 balls at 21 °C (RT) and 150 °C (HT) by reciprocating wear technique. The tribolayers were analyzed by XPS technique. Friction coefficients of TiN were 0.56, 0.35 for 21 °C and 150 °C tests, respectively. Rhenium addition to TiN drastically dropped the friction coefficients to 0.22 and 0.17 for RT and HT samples. Rhenium addition also improved the wear resistance of the coating at both test temperatures. For TiN, main oxide component of the tribolayers was Ti2O3 for RT tests and TiO2 for HT tests. The oxide layer formed on (Ti,Re)N were the mixture of TiO2, Tisbnd Osbnd N, ReO2 and Re2O7 for both test temperatures. Re2O7 provided very low friction coefficient to (Ti,Re)N. The findings are consistent with the crystal chemistry approach.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Embong, Zaidi, E-mail: zaidi@uthm.edu.my; Research Centre for Soft Soils; Johar, Saffuwan

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-Jerangaumore » 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.« less

Ambient Pressure XPS Study of Mixed Conducting Perovskite-Type SOFC Cathode and Anode Materials under Well-Defined Electrochemical Polarization

PubMed Central

2015-01-01

The oxygen exchange activity of mixed conducting oxide surfaces has been widely investigated, but a detailed understanding of the corresponding reaction mechanisms and the rate-limiting steps is largely still missing. Combined in situ investigation of electrochemically polarized model electrode surfaces under realistic temperature and pressure conditions by near-ambient pressure (NAP) XPS and impedance spectroscopy enables very surface-sensitive chemical analysis and may detect species that are involved in the rate-limiting step. In the present study, acceptor-doped perovskite-type La0.6Sr0.4CoO3-δ (LSC), La0.6Sr0.4FeO3-δ (LSF), and SrTi0.7Fe0.3O3-δ (STF) thin film model electrodes were investigated under well-defined electrochemical polarization as cathodes in oxidizing (O2) and as anodes in reducing (H2/H2O) atmospheres. In oxidizing atmosphere all materials exhibit additional surface species of strontium and oxygen. The polaron-type electronic conduction mechanism of LSF and STF and the metal-like mechanism of LSC are reflected by distinct differences in the valence band spectra. Switching between oxidizing and reducing atmosphere as well as electrochemical polarization cause reversible shifts in the measured binding energy. This can be correlated to a Fermi level shift due to variations in the chemical potential of oxygen. Changes of oxidation states were detected on Fe, which appears as FeIII in oxidizing atmosphere and as mixed FeII/III in H2/H2O. Cathodic polarization in reducing atmosphere leads to the reversible formation of a catalytically active Fe0 phase. PMID:26877827

A confirmative clinimetric analysis of the 36-item Family Assessment Device.

PubMed

Timmerby, Nina; Cosci, Fiammetta; Watson, Maggie; Csillag, Claudio; Schmitt, Florence; Steck, Barbara; Bech, Per; Thastum, Mikael

2018-02-07

The Family Assessment Device (FAD) is a 60-item questionnaire widely used to evaluate self-reported family functioning. However, the factor structure as well as the number of items has been questioned. A shorter and more user-friendly version of the original FAD-scale, the 36-item FAD, has therefore previously been proposed, based on findings in a nonclinical population of adults. We aimed in this study to evaluate the brief 36-item version of the FAD in a clinical population. Data from a European multinational study, examining factors associated with levels of family functioning in adult cancer patients' families, were used. Both healthy and ill parents completed the 60-item version FAD. The psychometric analyses conducted were Principal Component Analysis and Mokken-analysis. A total of 564 participants were included. Based on the psychometric analysis we confirmed that the 36-item version of the FAD has robust psychometric properties and can be used in clinical populations. The present analysis confirmed that the 36-item version of the FAD (18 items assessing 'well-being' and 18 items assessing 'dysfunctional' family function) is a brief scale where the summed total score is a valid measure of the dimensions of family functioning. This shorter version of the FAD is, in accordance with the concept of 'measurement-based care', an easy to use scale that could be considered when the aim is to evaluate self-reported family functioning.

Ground-based Parallax Confirmed by Spitzer: Binary Microlensing Event MOA-2015-BLG-020

NASA Astrophysics Data System (ADS)

Wang, Tianshu; Zhu, Wei; Mao, Shude; Bond, I. A.; Gould, A.; Udalski, A.; Sumi, T.; Bozza, V.; Ranc, C.; Cassan, A.; Yee, J. C.; Han, C.; Abe, F.; Asakura, Y.; Barry, R.; Bennett, D. P.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Hirao, Y.; Itow, Y.; Kawasaki, K.; Koshimoto, N.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Miyazaki, S.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Rattenbury, N.; Saito, To.; Sharan, A.; Shibai, H.; Sullivan, D. J.; Suzuki, D.; Tristram, P. J.; Yamada, T.; Yonehara, A.; MOA Collaboration; KozŁowski, S.; Mróz, P.; Pawlak, M.; Pietrukowicz, P.; Poleski, R.; Skowron, J.; Soszyński, I.; Szymański, M. K.; Ulaczyk, K.; OGLE Collaboration; Beichman, C.; Bryden, G.; Calchi Novati, S.; Carey, S.; Fausnaugh, M.; Gaudi, B. S.; Henderson, C. B.; Shvartzvald, Y.; Wibking, B.; Spitzer Team; Albrow, M. D.; Chung, S.-J.; Hwang, K.-H.; Jung, Y. K.; Ryu, Y.-H.; Shin, I.-G.; Cha, S.-M.; Kim, D.-J.; Kim, H.-W.; Kim, S.-L.; Lee, C.-U.; Lee, Y.; Park, B.-G.; Pogge, R. W.; KMTNet Collaboration; Street, R. A.; Tsapras, Y.; Hundertmark, M.; Bachelet, E.; Dominik, M.; Horne, K.; Figuera Jaimes, R.; Wambsganss, J.; Bramich, D. M.; Schmidt, R.; Snodgrass, C.; Steele, I. A.; Menzies, J.; RoboNet Collaboration

2017-08-01

We present the analysis of the binary gravitational microlensing event MOA-2015-BLG-020. The event has a fairly long timescale (˜63 days) and thus the light curve deviates significantly from the lensing model that is based on the rectilinear lens-source relative motion. This enables us to measure the microlensing parallax through the annual parallax effect. The microlensing parallax parameters constrained by the ground-based data are confirmed by the Spitzer observations through the satellite parallax method. By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing, the physical parameters of the lens are determined. It is found that the binary lens is composed of two dwarf stars with masses {M}1=0.606+/- 0.028 {M}⊙ and {M}2=0.125 +/- 0.006 {M}⊙ in the Galactic disk. Assuming that the source star is at the same distance as the bulge red clump stars, we find the lens is at a distance {D}L=2.44+/- 0.10 {kpc}. We also provide a summary and short discussion of all of the published microlensing events in which the annual parallax effect is confirmed by other independent observations.

Low-temperature thermal reduction of graphene oxide: In situ correlative structural, thermal desorption, and electrical transport measurements

NASA Astrophysics Data System (ADS)

Lipatov, Alexey; Guinel, Maxime J.-F.; Muratov, Dmitry S.; Vanyushin, Vladislav O.; Wilson, Peter M.; Kolmakov, Andrei; Sinitskii, Alexander

2018-01-01

Elucidation of the structural transformations in graphene oxide (GO) upon reduction remains an active and important area of research. We report the results of in situ heating experiments, during which electrical, mass spectrometry, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM) measurements were carried out correlatively. The simultaneous electrical and temperature programmed desorption measurements allowed us to correlate the onset of the increase in the electrical conductivity of GO by five orders of magnitude at about 150 °C with the maxima of the rates of desorption of H2O, CO, and CO2. Interestingly, this large conductivity change happens at an intermediate level of the reduction of GO, which likely corresponds to the point when the graphitic domains become large enough to enable percolative electronic transport. We demonstrate that the gas desorption is intimately related to (i) the changes in the chemical structure of GO detected by XPS and Raman spectroscopy and (ii) the formation of nanoscopic holes in GO sheets revealed by TEM. These in situ observations provide a better understanding of the mechanism of the GO thermal reduction.

Development of the performance confirmation program at YUCCA mountain, nevada

USGS Publications Warehouse

LeCain, G.D.; Barr, D.; Weaver, D.; Snell, R.; Goodin, S.W.; Hansen, F.D.

2006-01-01

The Yucca Mountain Performance Confirmation program consists of tests, monitoring activities, experiments, and analyses to evaluate the adequacy of assumptions, data, and analyses that form the basis of the conceptual and numerical models of flow and transport associated with a proposed radioactive waste repository at Yucca Mountain, Nevada. The Performance Confirmation program uses an eight-stage risk-informed, performance-based approach. Selection of the Performance Confirmation activities for inclusion in the Performance Confirmation program was done using a risk-informed performance-based decision analysis. The result of this analysis was a Performance Confirmation base portfolio that consists of 20 activities. The 20 Performance Confirmation activities include geologic, hydrologie, and construction/engineering testing. Some of the activities began during site characterization, and others will begin during construction, or post emplacement, and continue until repository closure.

10 CFR 60.137 - General requirements for performance confirmation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... IN GEOLOGIC REPOSITORIES Technical Criteria Performance Confirmation Requirements § 60.137 General requirements for performance confirmation. The geologic repository operations area shall be designed so as to...

Measuring motivation for medical treatment: confirming the factor structure of the Achievement Motivation Index for Medical Treatment (AMI-MeT).

PubMed

Hatta, Taichi; Narita, Keiichi; Naria, Keiichi; Yanagihara, Kazuhiro; Ishiguro, Hiroshi; Murayama, Toshinori; Yokode, Masayuki

2016-02-19

Developments in chemotherapy have led to changes in cancer care in Japan, with the government promoting a transition to outpatient chemotherapy. This requires patients and their families to participate more actively in treatment than in the past. However, it remains unclear how patients' motivation for medical treatment affects clinical consultations with their physicians. To investigate this, we developed a psychological index called the Achievement Motive Index for Medical Treatment (AMI-MeT), which comprises self-derived achievement motivation (AMS) and achievement motivation derived from others (AMO). However, its factor structure has not yet been confirmed in populations other than healthy university students. Thus, the aims of this study were to confirm the factor structure of the AMI-MeT in other groups and to determine the convergent and divergent validity of the AMI-MeT. The AMI-MeT was administered to university students (n = 414), apparently healthy workers (n = 154), and cancer patients (n = 51). Multi-group confirmatory factor analysis was conducted and the mean scores of the AMI-MeT were compared between the groups. Correlations between the AMI-MeT and the Self-Construal Scale, comprising independent self-construal (IndSC) and interdependent self-construal (InterSC) subscales, were investigated in another group of students (n = 335). The multi-group confirmatory factor analysis supported a two-factor structure of the AMI-MeT: the weak invariance model was the best fit for the data. The mean scores of the AMI-MeT in apparently healthy workers and cancer patients were significantly higher than that in students (P < .01). The correlation analysis revealed that AMS scores were associated with IndSC scores (r = .25, P < .01) and AMO scores with InterSC scores (r = .30, P < .01). The two-factor model of the AMI-MeT was deemed appropriate for all three groups, and the subscales of the AMI-MeT successfully reflected the

Thalassaemia screening and confirmation of carriers in parents.

PubMed

Barrett, Angela N; Saminathan, Ramasamy; Choolani, Mahesh

2017-02-01

Haemoglobinopathies are among the most common inherited monogenic disorders worldwide. Thalassaemia screening for carrier status is recommended for adults of reproductive age if suspected of being at risk. Conventional laboratory methods for screening include the assessment of haematological indices, and high-performance liquid chromatography, capillary electrophoresis or isoelectric focusing to measure the levels of HbA 2 and HbF, and to identify haemoglobin variants. Each screening method has its advantages and disadvantages, the main disadvantage being that none can fully resolve all variants. The complex nature of the genetics of haemoglobinopathies necessitates expertise in the interpretation of screening results to evaluate the most likely genotypes, which must then be confirmed using the DNA diagnosis. This review highlights the limits and pitfalls of each screening technique, and outlines a rational combination of different methods to overcome issues in thalassaemia carrier detection. Copyright © 2016. Published by Elsevier Ltd.

Effect of nitrogen plasma afterglow on the surface charge effect resulted during XPS surface analysis of amorphous carbon nitride thin films

NASA Astrophysics Data System (ADS)

Kayed, Kamal

2018-06-01

The aim of this paper is to investigate the relationship between the micro structure and the surface charge effect resulted during XPS surface analysis of amorphous carbon nitride thin films prepared by laser ablation method. The study results show that the charge effect coefficient (E) is not just a correction factor. We found that the changes in this coefficient value due to incorporation of nitrogen atoms into the carbon network are related to the spatial configurations of the sp2 bonded carbon atoms, order degree and sp2 clusters size. In addition, results show that the curve E vs. C(sp3)-N is a characteristic curve of the micro structure. This means that using this curve makes it easy to sorting the samples according to the micro structure (hexagonal rings or chains).

Structural confirmation of oligosaccharides newly isolated from sugar beet molasses.

PubMed

Abe, Tatsuya; Horiuchi, Kenichi; Kikuchi, Hiroto; Aritsuka, Tsutomu; Takata, Yusuke; Fukushi, Eri; Fukushi, Yukiharu; Kawabata, Jun; Ueno, Keiji; Onodera, Shuichi; Shiomi, Norio

2012-08-27

Sugar beet molasses is a viscous by-product of the processing of sugar beets into sugar. The molasses is known to contain sucrose and raffinose, a typical trisaccharide, with a well-established structure. Although sugar beet molasses contains various other oligosaccharides as well, the structures of those oligosaccharides have not been examined in detail. The purpose of this study was isolation and structural confirmation of these other oligosaccharides found in sugar beet molasses. Four oligosaccharides were newly isolated from sugar beet molasses using high-performance liquid chromatography (HPLC) and carbon-Celite column chromatography. Structural confirmation of the saccharides was provided by methylation analysis, matrix-assisted laser desorption/ionaization time of flight mass spectrometry (MALDI-TOF-MS), and nuclear magnetic resonance (NMR) measurements. The following oligosaccharides were identified in sugar beet molasses: β-D-galactopyranosyl-(1- > 6)-β-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named β-planteose), α-D-galactopyranosyl-(1- > 1)-β-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named1-planteose), α-D-glucopyranosyl-(1- > 6)-α-D-glucopyranosyl-(1 <-> 2)-β-D-fructofuranoside (theanderose), and β-D-glucopyranosyl-(1- > 3)-α-D-glucopyranosyl-(1 <-> 2)-β-D-fructofuranoside (laminaribiofructose). 1-planteose and laminaribiofructose were isolated from natural sources for the first time.

XPS investigation of the photon degradation of Znq2 green organic phosphor

NASA Astrophysics Data System (ADS)

Duvenhage, Mart-Mari; Terblans, Jacobus J.; Ntwaeaborwa, Martin; Swart, Hendrik C.

2016-01-01

By substituting Al with Zn to form bis-(8-hydroxyquinoline) zinc (Znq2), the device performance of organic light emitting diodes (OLED) can be improved. Znq2 also has a more closed packed crystal structure that makes it less vulnerable to reactions with atmospheric oxygen and moisture leading to more stable and longer lasting devices. In this work the effect of photon degradation of Znq2 in air was investigated. Znq2 powder was synthesized using a co-precipitation method and recrystallized in acetone. The structure of the sample was confirmed to be Znq2·2H2O by X-ray diffraction. The photoluminescence (PL) emission data also confirmed that the Znq2·2H2O crystal form of Znq2 was present. To study the photon degradation, the sample was irradiated with a UV lamp for 400 h. The emission data was collected and the change in PL intensity with time was monitored. X-ray photoelectron spectroscopy was performed on the as prepared and photon-degraded samples. The Zn2p and N1s peaks showed no change after degradation. The O1s and C1s peaks confirmed that the phenoxide ring ruptured and that C=O and C-O species had formed.

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

NASA Technical Reports Server (NTRS)

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.

Influence of Ga vacancies, Mn and O impurities on the ferromagnetic properties of GaN micro- and nanostructures

NASA Astrophysics Data System (ADS)

Guzmán, G.; Escudero, R.; Silva, R.; Herrera, M.

2018-04-01

We present a study of the influence of gallium vacancy (VGa) point defects on the ferromagnetic properties of GaN:Mn and GaN:Mn,O micro- and nanostructures. Results demonstrate that the generation of these point defects enhances the ferromagnetic signal of GaN:Mn microstructures, while incorporation of oxygen as an impurity inhibits this property. XPS measurements revealed that Mn impurities in ferromagnetic GaN:Mn samples mainly exhibit a valence state of 2+. Cathodoluminescence (CL) spectra from Mn-doped GaN samples displayed emissions centered at about 1.97 eV, attributed to transitions between the 4T1-6A1 states of the Mn2+ d orbitals, and emissions centered at 2.45 and 2.9 eV, associated with the presence of VGa. CL measurements also revealed a blue shift of the GaN band-edge emission generated by the expansion of the wurtzite lattice due to Mn incorporation, which was confirmed by XRD measurements. These latter measurements also revealed an amorphization of GaN:Mn due to the incorporation of oxygen as impurities. The GaN:Mn samples were synthesized by thermal evaporation of GaN and MnCO3 powders onto Ni0.8Cr0.2/Si(100) in a horizontal furnace operated at low vacuum. The residual air inside the system was used as a source of oxygen during the synthesis of Mn and O co-doped GaN nanostructures. Mn and O impurities were incorporated into the nanostructures at different concentrations by varying the growth temperature. Energy Dispersive Spectroscopy, XRD, and XPS measurements confirmed that the obtained samples predominantly consisted of GaN.

Ion beam modification of zinc white pigment characterized by ex situ and in situ μ-Raman and XPS

NASA Astrophysics Data System (ADS)

Beck, L.; Gutiérrez, P. C.; Miro, S.; Miserque, F.

2017-10-01

Zinc oxide, known as zinc white, is one of the principal white pigments developed in the 18th century and was used by the Impressionist painters. ZnO as artists' pigment has occasionally been characterized by X-ray and ion beam techniques, but these studies are limited by the potential for visible radiation effect. Ion beam modifications of zinc oxide have extensively been investigated, but mainly for electronic and industrial applications. In this paper, we focus our investigation on ion beam modification of ZnO used as pigment. Two irradiation conditions have been used: an external 3 MeV proton micro-beam representative of PIXE analysis and 2 MeV H+ and 1.2 MeV Au + beams in vacuum to investigate irradiation modifications in electronic and nuclear energy loss regimes. Ion beam modification was characterized by ex situ and in situ micro-Raman spectrometry and XPS. The results shows that IBA of zinc white can be carried out safely in historical paintings with low current and dose.

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

PubMed Central

Rheinheimer, Vanessa; Unluer, Cise; Liu, Jiawei; Ruan, Shaoqin; Pan, Jisheng; Monteiro, Paulo J. M.

2017-01-01

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(OH)2, 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. PMID:28772437

Reaction of propane with the ordered NiO/Rh(1 1 1) studied by XPS and LEISS

NASA Astrophysics Data System (ADS)

Zhang, Hong; Wang, Wenyi; Chen, Mingshu; Wan, Huilin

2018-05-01

Nickel oxide has been reported to be an efficient catalyst for oxidative dehydrogenation of propane (ODP) to propene at low temperature. In this paper, ultrathin NiO films with various thickness were prepared on a Rh(1 1 1) surface and characterized by X-ray photoemission spectroscopy (XPS) and Low-energy ion scattering spectroscopy (LEISS). Results show that NiO forms a two-dimensional (2D) network with a O-Ni-O structure at submonolayer coverages, and a bulk-like NiO at multilayer coverages. The submonolayer NiO films are less stable than the thick ones when annealed in ultra-high vacuum (UHV) due to the strong interaction with the Rh substrate. Propane was dosed onto the model surfaces at different temperatures to investigate the activation of propane and reactivity of NiO films with propane. The reactions of propane with the thin and thick NiO films are significantly different. Propane activates on the O defect sites for the thick NiO films, whereas activation occurs on the interface of nickel oxide and substrate for the thin films with a higher activity.

Michael Griffin Senate Confirmation Hearing

NASA Image and Video Library

2005-04-12

U.S. Senator Barbara Mikulski, D-Md., left, talks with Michael Griffin as Senator Kay Bailey Hutchison, R-Tx., and Griffin's wife Rebecca look on prior to his testimony, Tuesday, April 12, 2005, at the Russell Senate Office Building in Washington. If confirmed, Griffin, who currently heads the space department at the Johns Hopkins University Applied Physics Laboratory will become NASA's 11th administrator. Photo Credit: (NASA/Renee Bouchard)

A combined ToF-SIMS and XPS study for the elucidation of the role of water in the performances of a Post-Plasma Process using LaMnO3+δ as catalyst in the total oxidation of trichloroethylene

NASA Astrophysics Data System (ADS)

Nuns, N.; Beaurain, A.; Dinh, M. T. Nguyen; Vandenbroucke, A.; De Geyter, N.; Morent, R.; Leys, C.; Giraudon, J.-M.; Lamonier, J.-F.

2014-11-01

LaMnO3+δ which is an environment-friendly and inexpensive material has been previously used as catalyst in Post-Plasma Catalysis (PPC) in the total oxidation of trichloroethylene (TCE) which is a solvent widely used in dry cleaning and degreasing processes. It has been shown that the process efficiency increases in moist air (RH = 18%).The issue we want to address herein is the effect of water on the location of chlorine at the surface of the catalyst as chlorine is able to alter the catalyst structure, activity and stability. Therefore, a combined Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS) study has been carried out on the fresh LaMnO3+δ catalyst (LM) and used catalysts after performing PPC with TCE diluted in dry synthetic air (LM0) or with industrial air containing water (LM18; 18 stands for the Relative Humidity) and CO2 (about 560 ppmv) at a temperature of 150 °C. XPS and ToF-SIMS results both show the presence of chlorine on the tested catalysts whose amount increases by exposure of the catalyst to the reactive mixture in dry synthetic air. XPS results reveal that chlorine is present as both chloride ion and covalent chlorine on LM0 while organic chlorinated residues are absent on LM18 catalyst. ToF-SIMS study indicates that lanthanum excess as oxide(hydroxide) partially covering the perovskite mainly transforms into LaOCl and to a minor extent into LaCl3. Extent of Mn chlorination seems to be favored over LM0 having a higher MnClx±/MnOCl± ionic ratio compared to LM18. Furthermore ToF-SIMS clearly identifies C1 chlorinated organic ions, mainly CH2Cl+ and CHCl2-, on LM0 which may contribute to the XPS Cl organic component. From the combined ToF-SIMS and XPS results it is found that water delays the surface degradation extent of the perovskite into related (oxy)(hydroxy)chlorinated inorganic phases by less molecular chlorine and related chlorine species on the catalyst surface. A reaction scheme of

Space Time Theories Confirmed

NASA Image and Video Library

2011-05-04

Seated from left, Bill Danchi, Senior Astrophysicist and Program Scientist at NASA Headquarters, Francis Everitt, Principal Investigator for the Gravity Probe B Mission at Stanford University, Rex Geveden, President of Teledyne Brown Engineering, Colleen Hartman, a research professor at George Washington University, and Clifford Will, Professor of Physics at Washington University in St. Louis, Mo., conduct a press conference, Wednesday, May 4, 2011, to discuss NASA's Gravity Probe B (GP-B) mission which has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test. at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

Toward a comprehensive understanding of solid-state core-level XPS linewidths: Experimental and theoretical studies on the Si2p and O1s linewidths in silicates

NASA Astrophysics Data System (ADS)

Bancroft, G. M.; Nesbitt, H. W.; Ho, R.; Shaw, D. M.; Tse, J. S.; Biesinger, M. C.

2009-08-01

High resolution X-ray Photoelectron Spectroscopy (XPS) core-level Si2p and O1s spectra of the nonconductors α-SiO2 (quartz) at 120 and 300 K and vitreous SiO2 at 300 K were obtained with a Kratos Axis Ultra XPS instrument (instrumental resolution of <0.4eV ) which incorporates a unique charge compensation system that minimizes differential charge broadening on nonconductors. The Si2p and O1s linewidths at 300 K ( ˜1.1 and ˜1.2eV , respectively) are similar for all silicates (and similar to previous thin film SiO2 spectra obtained previously), showing that differential charging does not contribute significantly to our spectra. At 120 K, there is a small decrease (0.04 eV) in the Si2p linewidth of α-SiO2 , but no measurable decrease in O1s linewidth. The O1s lines are generally and distinctly asymmetric. We consider all possible sources of line broadening and show that final state vibrational broadening (FSVB) and phonon broadening are the major causes of the broad and asymmetric lines. Previous high resolution gas phase XPS studies have identified large FSVB contributions to the Si2p spectra of SiCl4 , SiF4 , and Si(OCH3)4 molecules, and this vibrational structure leads total Si2p3/2 linewidths of up to ˜0.5eV , even with individual peak linewidths of <0.1eV . The Si atom of Si(OCH3)4 is an excellent analog for Si in crystalline SiO2 because the Si-O bond lengths and symmetric stretch frequencies are similar in both compounds. Similar vibrational contributions to the Si2p and O1s spectra of solid silicates are anticipated if the Si2p and O1s core-hole states produce similar changes to the Si-O bond length in both phases. To investigate the possibility, Car-Parrinello molecular dynamics calculations were performed and show that changes to Si-O bond lengths between ion and ground states (Δr) for both Si2p and O1s hole states are similar for both crystalline SiO2 and gaseous Si(OCH3)4 . Δr are -0.04Å for Si2p and ˜+0.05Å for O1s in both compounds. Indeed, the

The Latest SORCE Solar Spectral Irradiance Data Release: Inter-Comparison and a First Look at TSIS SIM Measurement.

NASA Astrophysics Data System (ADS)

Beland, S.; Sandoval, L.; Vanier, B.; Elliott, J.; Harder, J. W.; Snow, M. A.; Woods, T. N.; Richard, E. C.; Pilewskie, P.

2017-12-01

The Spectral Irradiance Monitor (SIM), the SOLar STellar Irradiance Comparison Experiment (SOLSTICE), and the XUV Photometer System (XPS) instruments on board the Solar Radiation and Climate Experiment (SORCE) mission have been taking daily Solar spectral irradiance (SSI) measurements since April 2003. We present the latest data releases from these instruments, describing the improvements in the new datasets and the trends measured during Solar cycles 23 and 24. An inter-comparison of the SSI over the overlapping wavelengths for SIM and SOLSTICE is presented as well as, if the data is available, a comparison with the first light measurements from TSIS-SIM.

Racial athletic stereotype confirmation in college football recruiting.

PubMed

Thomas, Grant; Good, Jessica J; Gross, Alexi R

2015-01-01

The present study tested real-world racial stereotype use in the context of college athletic recruiting. Stereotype confirmation suggests that observers use stereotypes as hypotheses and interpret relevant evidence in a biased way that confirms their stereotypes. Shifting standards suggest that the evaluative standard to which we hold a target changes as a function of their group membership. We examined whether stereotype confirmation and shifting standards effects would be seen in college football coaches during recruiting. College football coaches evaluated a Black or White player on several attributes and made both zero- and non-zero-sum allocations. Results suggested that coaches used the evidence presented to develop biased subjective evaluations of the players based on race while still maintaining equivalent objective evaluations. Coaches also allocated greater overall resources to the Black recruit than the White recruit.

Vibrational spectra of nanowires measured using laser doppler vibrometry and STM studies of epitaxial graphene : an LDRD fellowship report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biedermann, Laura Butler

2009-09-01

MWNTs, their vibration spectra was more extensively studied. The thermal vibration spectra of Ag{sub 2}Ga nanoneedles was measured under both ambient and low-vacuum conditions. The operational deflection shapes of the vibrating Ag{sub 2}Ga nanoneedles was also measured, allowing confirmation of the eigenmodes of vibration. The modulus of the crystalline nanoneedles was 84.3 {+-} 1.0 GPa. Gas damping is the dominate mechanism of energy loss for nanowires oscillating under ambient conditions. The measured quality factors, Q, of oscillation are in line with theoretical predictions of air damping in the free molecular gas damping regime. In the free molecular regime, Q{sub gas} is linearly proportional to the density and diameter of the nanowire and inversely proportional to the air pressure. Since the density of the Ag{sub 2}Ga nanoneedles is three times that of the MWNTs, the Ag{sub 2}Ga nanoneedles have greater Q at atmospheric pressures. Our initial measurements of Q for Ag{sub 2}Ga nanoneedles in low-vacuum (10 Torr) suggest that the intrinsic Q of these nanoneedles may be on the order of 1000. The epitaxial carbon that grows after heating (000{bar 1}) silicon carbide (SiC) to high temperatures (1450-1600) in vacuum was also studied. At these high temperatures, the surface Si atoms sublime and the remaining C atoms reconstruct to form graphene. X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM) were used to characterize the quality of the few-layer graphene (FLG) surface. The XPS studies were useful in confirming the graphitic composition and measuring the thickness of the FLG samples. STM studies revealed a wide variety of nanometer-scale features that include sharp carbon-rich ridges, moire superlattices, one-dimensional line defects, and grain boundaries. By imaging these features with atomic scale resolution, considerable insight into the growth mechanisms of FLG on the carbon-face of SiC is obtained.« less

Confirming psychogenic nonepileptic seizures with video-EEG: sex matters.

PubMed

Noe, Katherine H; Grade, Madeline; Stonnington, Cynthia M; Driver-Dunckley, Erika; Locke, Dona E C

2012-03-01

The influence of gender on psychogenic nonepileptic seizures (PNES) diagnosis was examined retrospectively in 439 subjects undergoing video-EEG (vEEG) for spell classification, of whom 142 women and 42 men had confirmed PNES. The epileptologist's predicted diagnosis was correct in 72% overall. Confirmed epilepsy was correctly predicted in 94% men and 88% women. In contrast, confirmed PNES was accurately predicted in 86% women versus 61% men (p=0.003). Sex-based differences in likelihood of an indeterminate admission were not observed for predicted epilepsy or physiologic events, but were for predicted PNES (39% men, 12% women, p=0.0002). More frequent failure to record spells in men than women with predicted PNES was not explained by spell frequency, duration of monitoring, age, medication use, or personality profile. PNES are not only less common in men, but also more challenging to recognize in the clinic, and even when suspected more difficult to confirm with vEEG. Copyright © 2012 Elsevier Inc. All rights reserved.

Thickness measurement of a thin hetero-oxide film with an interfacial oxide layer by X-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Kim, Kyung Joong; Lee, Seung Mi; Jang, Jong Shik; Moret, Mona

2012-02-01

The general equation Tove = L cos θ ln(Rexp/R0 + 1) for the thickness measurement of thin oxide films by X-ray photoelectron spectroscopy (XPS) was applied to a HfO2/SiO2/Si(1 0 0) as a thin hetero-oxide film system with an interfacial oxide layer. The contribution of the thick interfacial SiO2 layer to the thickness of the HfO2 overlayer was counterbalanced by multiplying the ratio between the intensity of Si4+ from a thick SiO2 film and that of Si0 from a Si(1 0 0) substrate to the intensity of Si4+ from the HfO2/SiO2/Si(1 0 0) film. With this approximation, the thickness levels of the HfO2 overlayers showed a small standard deviation of 0.03 nm in a series of HfO2 (2 nm)/SiO2 (2-6 nm)/Si(1 0 0) films. Mutual calibration with XPS and transmission electron microscopy (TEM) was used to verify the thickness of HfO2 overlayers in a series of HfO2 (1-4 nm)/SiO2 (3 nm)/Si(1 0 0) films. From the linear relation between the thickness values derived from XPS and TEM, the effective attenuation length of the photoelectrons and the thickness of the HfO2 overlayer could be determined.

SU-E-T-124: Anthropomorphic Phantoms for Confirmation of Linear Accelerator Based Small Animal Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perks, J; Benedict, S; Lucero, S

Purpose: To document the support of radiobiological small animal research by a modern radiation oncology facility. This study confirms that a standard, human use linear accelerator can cover the range of experiments called for by researchers performing animal irradiation. A number of representative, anthropomorphic murine phantoms were made. The phantoms confirmed the small field photon and electron beams dosimetry validated the use of the linear accelerator for rodents. Methods: Laser scanning a model, CAD design and 3D printing produced the phantoms. The phantoms were weighed and CT scanned to judge their compatibility to real animals. Phantoms were produced to specificallymore » mimic lung, gut, brain, and othotopic lesion irradiations. Each phantom was irradiated with the same protocol as prescribed to the live animals. Delivered dose was measured with small field ion chambers, MOS/FETs or TLDs. Results: The density of the phantom material compared to density range across the real mice showed that the printed material would yield sufficiently accurate measurements when irradiated. The whole body, lung and gut irradiations were measured within 2% of prescribed doses with A1SL ion chamber. MOSFET measurements of electron irradiations for the orthotopic lesions allowed refinement of the measured small field output factor to better than 2% and validated the immunology experiment of irradiating one lesion and sparing another. Conclusion: Linacs are still useful tools in small animal bio-radiation research. This work demonstrated a strong role for the clinical accelerator in small animal research, facilitating standard whole body dosing as well as conformal treatments down to 1cm field. The accuracy of measured dose, was always within 5%. The electron irradiations of the phantom brain and flank tumors needed adjustment; the anthropomorphic phantoms allowed refinement of the initial output factor measurements for these fields which were made in a large block of

Confirmation of theoretical colour predictions for layering dental composite materials.

PubMed

Mikhail, Sarah S; Johnston, William M

2014-04-01

The aim of this study is to confirm the theoretical colour predictions for single and double layers of dental composite materials on an opaque backing. Single and double layers of composite resins were fabricated, placed in optical contact with a grey backing and measured for spectral radiance. The spectral reflectance and colour were directly determined. Absorption and scattering coefficients as previously reported, the measured thickness of the single layers and the effective reflectance of the grey backing were utilized to theoretically predict the reflectance of the single layer using corrected Kubelka-Munk reflectance theory. For double layers the predicted effective reflectance of the single layer was used as the reflectance of the backing of the second layer and the thickness of the second layer was used to predict the reflectance of the double layer. Colour differences, using both the CIELAB and CIEDE2000 formulae, measured the discrepancy between each directly determined colour and its corresponding theoretical colour. The colour difference discrepancies generally ranged around the perceptibility threshold but were consistently below the respective acceptability threshold. This theory can predict the colour of layers of composite resin within acceptability limits and generally also within perceptibility limits. This theory could therefore be incorporated into computer-based optical measuring instruments that can automate the shade selections for layers of a more opaque first layer under a more translucent second layer for those clinical situations where an underlying background colour and a desirable final colour can be measured. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surgical versus injection treatment for injection-confirmed chronic sacroiliac joint pain

PubMed Central

Spiker, William Ryan; Lawrence, Brandon D.; Raich, Annie L.; Skelly, Andrea C.; Brodke, Darrel S.

2012-01-01

Study design: Systematic review. Study rationale: Chronic sacroiliac joint pain (CSJP) is a common clinical entity with highly controversial treatment options. A recent systematic review compared surgery with denervation, but the current systematic review compares outcomes of surgical intervention with therapeutic injection for the treatment of CSJP and serves as the next step for evaluating current evidence on the comparative effectiveness of treatments for non-traumatic sacroiliac joint pain. Objective or clinical question: In adult patients with injection-confirmed CSJP, does surgical treatment lead to better outcomes and fewer complications than injection therapy? Methods: A systematic review of the English-language literature was undertaken for articles published between 1970 and June 2012. Electronic databases and reference lists of key articles were searched to identify studies evaluating surgery or injection treatment for injection-confirmed CSJP. Studies involving traumatic onset or non-injection–confirmed CSJP were excluded. Two independent reviewers assessed the level of evidence quality using the grading of recommendations assessment, development and evaluation (GRADE) system, and disagreements were resolved by consensus. Results: We identified twelve articles (seven surgical and five injection treatment) meeting our inclusion criteria. Regardless of the type of treatment, most studies reported over 40% improvement in pain as measured by Visual Analog Scale or Numeric rating Scale score. Regardless of the type of treatment, most studies reported over 20% improvement in functionality. Most complications were reported in the surgical studies. Conclusion: Surgical fusion and therapeutic injections can likely provide pain relief, improve quality of life, and improve work status. The comparative effectiveness of these interventions cannot be evaluated with the current literature. PMID:23526911

Experimental confirmation of Lenz’s law

NASA Astrophysics Data System (ADS)

Mayer, V. V.; Varaksina, E. I.

2017-11-01

The paper presents a series of experiments that demonstrate the phenomenon of electromagnetic induction. These make it possible to determine the direction of the induced current and so confirm Lenz’s Law. The simple experiments can be reproduced in a school laboratory and can be recommended for students’ project activity.

Association between bacterial infection and radiologically confirmed pneumonia among children.

PubMed

Nascimento-Carvalho, Cristiana M; Araújo-Neto, César A; Ruuskanen, Olli

2015-05-01

The role of chest radiograph (CXR) among children with community-acquired pneumonia is controversial. We aimed to assess if there is association between a specific etiology and radiologically confirmed pneumonia. This was a prospective cross-sectional study. Based on report of respiratory complaints and fever/difficulty breathing plus the detection of pulmonary infiltrate/pleural effusion on the CXR taken upon admission read by the pediatrician on duty, children <5-year-old hospitalized with community-acquired pneumonia were enrolled. On admission, clinical data and biological samples were collected to investigate 19 etiological agents (11 viruses and 8 bacteria). CXR taken upon admission was independently read by a pediatric radiologist blinded to clinical data. The study group comprised 209 cases with evaluated CXR and establishment of a probable etiology. Radiologically confirmed pneumonia, normal CXR and other radiographic diagnoses were described for 165 (79.0%), 36 (17.2%) and 8 (3.8%) patients, respectively. Viral infection was significantly more common among patients without radiologically confirmed pneumonia (68.2% vs. 47.9%; P = 0.02), particularly among those with normal CXR (66.7% vs. 47.9%; P = 0.04) when compared with patients with radiologically confirmed pneumonia. Bacterial infection was more frequent among cases with radiologically confirmed pneumonia (52.1% vs. 31.8%; P = 0.02). Likewise, pneumococcal infection was more frequently detected among children with radiologically confirmed pneumonia in regard to children with normal CXR (24.2% vs. 8.3%; P = 0.04). Sensitivity (95% confidence interval) of radiologically confirmed pneumonia for pneumococcal infection was 93% (80-98%), and negative predictive value (95% confidence interval) of normal CXR for pneumococcal infection was 92% (77-98%). Bacterial infection, especially pneumococcal one, is associated with radiologically confirmed pneumonia.

Stability of Phosphonic Self Assembled Monolayers (SAMs) on Cobalt Chromium (Co-Cr) Alloy under Oxidative conditions

PubMed Central

Bhure, Rahul; Abdel-Fattah, Tarek M.; Bonner, Carl; Hall, Felicia; Mahapatro, Anil

2011-01-01

Cobalt Chromium (Co-Cr) alloys has been widely used in the biomedical arena for cardiovascular, orthopedic and dental applications. Surface modification of the alloy allows us to tailor the interfacial properties to address critical challenges of Co-Cr alloy in medical applications. Self assembled monolayers (SAMs) of Octadecylphosphonic acid (ODPA) have been used to form thin films on the oxide layer of the Co-Cr alloy surface by solution deposition technique. The SAMs formed were investigated for their stability to oxidative conditions of ambient laboratory environment over periods of 1, 3, 7 and 14 days. The samples were then characterized for their stability using X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and Contact Angle Measurements. Detailed high energy XPS elemental scans confirmed the presence of the phosphonic monolayer after oxidative exposure which suggested that the SAMs were firmly attached to the oxide layer of Co-Cr alloy. AFM images gave topographical data of the surface and showed islands of SAMs on Co-Cr alloy surface, before and after SAM formation and also over the duration of the oxidative exposure. Contact angle measurements confirmed the hydrophobicity of the surface over 14 days. Thus the SAMs were found to be stable for the duration of the study. These SAMs could be subsequently tailored by modifying the terminal functional groups and could be used for various potential biomedical applications such as drug delivery, biocompatibility and tissue integration PMID:21603056

WHY ARE RAPIDLY ROTATING M DWARFS IN THE PLEIADES SO (INFRA)RED? NEW PERIOD MEASUREMENTS CONFIRM ROTATION-DEPENDENT COLOR OFFSETS FROM THE CLUSTER SEQUENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Covey, Kevin R.; Agüeros, Marcel A.; Liu, Jiyu

2016-05-10

Stellar rotation periods ( P {sub rot}) measured in open clusters have proved to be extremely useful for studying stars’ angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While P {sub rot} measurements have been obtained for hundreds of solar-mass members of the Pleiades, measurements exist for only a few low-mass (<0.5 M {sub ⊙}) members of this key laboratory for stellar evolution theory. To fill this gap, we report P {sub rot} for 132 low-mass Pleiades members (including nearly 100 with M ≤ 0.45 M {sub ⊙}), measured from photometric monitoring ofmore » the cluster conducted by the Palomar Transient Factory in late 2011 and early 2012. These periods extend the portrait of stellar rotation at 125 Myr to the lowest-mass stars and re-establish the Pleiades as a key benchmark for models of the transport and evolution of stellar angular momentum. Combining our new P {sub rot} with precise BVIJHK photometry reported by Stauffer et al. and Kamai et al., we investigate known anomalies in the photometric properties of K and M Pleiades members. We confirm the correlation detected by Kamai et al. between a star's P {sub rot} and position relative to the main sequence in the cluster's color–magnitude diagram. We find that rapid rotators have redder ( V − K ) colors than slower rotators at the same V , indicating that rapid and slow rotators have different binary frequencies and/or photospheric properties. We find no difference in the photometric amplitudes of rapid and slow rotators, indicating that asymmetries in the longitudinal distribution of starspots do not scale grossly with rotation rate.« less

Stages of Se adsorption on Au(111): A combined XPS, LEED, TOF-DRS, and DFT study

NASA Astrophysics Data System (ADS)

Ruano, G.; Tosi, E.; Sanchez, E.; Abufager, P.; Martiarena, M. L.; Grizzi, O.; Zampieri, G.

2017-08-01

We have studied the adsorption of Se on the surface Au(111) using XPS, TOF-DRS, LEED and DFT calculations. The use of a doser that operates in vacuum allowed us to investigate all the stages of the adsorption from the clean surface up to the formation of multilayers. In the monolayer regime we have found two ordered phases with distinctive LEED patterns. The LEED pattern of the first phase presents three fractional spots arranged symmetrically around the positions of the spots in a √3x√3 pattern. The analysis of this pattern suggests the formation of either a nxn superstructure of √3x√3 domains with n=19 or n=22, or that the adsorption occurs without removing the 22x√3 herringbone reconstruction of the gold surface. This last possibility is in accordance with DFT calculations which show that the charge transfer to a Se adsorbate might not be enough to destabilize the surface reconstruction. Increasing the coverage, beyond 0.3 ML a new LEED pattern appears with broad spots which upon annealing at 150 °C become well defined indicating a 1×8 periodicity. At the highest doses we have observed the formation of multilayers with no discernible LEED pattern. The comparison with adsorption experiments carried out in liquid solutions show similarities and also some important differences.

Effects of rare earth doping on multi-core iron oxide nanoparticles properties

NASA Astrophysics Data System (ADS)

Petran, Anca; Radu, Teodora; Borodi, Gheorghe; Nan, Alexandrina; Suciu, Maria; Turcu, Rodica

2018-01-01

New multi-core iron oxide magnetic nanoparticles doped with rare earth metals (Gd, Eu) were obtained by a one step synthesis procedure using a solvothermal method for potential biomedical applications. The obtained clusters were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray microanalysis (EDX), X-ray photoelectron spectroscopy (XPS) and magnetization measurements. They possess high colloidal stability, a saturation magnetization of up to 52 emu/g, and nearly spherical shape. The presence of rare earth ions in the obtained samples was confirmed by EDX and XPS. XRD analysis proved the homogeneous distribution of the trivalent rare earth ions in the inverse-spinel structure of magnetite and the increase of crystal strain upon doping the samples. XPS study reveals the valence state and the cation distribution on the octahedral and tetrahedral sites of the analysed samples. The observed shift of the XPS valence band spectra maximum in the direction of higher binding energies after rare earth doping, as well as theoretical valence band calculations prove the presence of Gd and Eu ions in octahedral sites. The blood protein adsorption ability of the obtained samples surface, the most important factor of the interaction between biomaterials and body fluids, was assessed by interaction with bovine serum albumin (BSA). The rare earth doped clusters surface show higher afinity for binding BSA. In vitro cytotoxicity test results for the studied samples showed no cytotoxicity in low and medium doses, establishing a potential perspective for rare earth doped MNC to facilitate multiple therapies in a single formulation for cancer theranostics.

Confirming Planetary Mass Candidate Companions in Ophiuchus

NASA Astrophysics Data System (ADS)

Fontanive, Clemence

2016-10-01

We propose for follow-up observations to confirm common proper motion for two candidate planetary mass companions, identified as part of our GO 12944 (PI Allers) search for companions to the youngest ( 0.5 Myr) brown dwarfs in the nearby Ophiuchus star-forming region. If confirmed to be co-moving, these would be among the lowest mass planetary mass companions imaged to date, with estimated masses <5 Jupiter Masses and would be vital benchmark objects for evolutionary models at these young ages. With our multi-band optical and IR photometric approach based on the SpT-Q relation seen for Ophiuchus brown dwarfs (Allers in prep.), we have already estimated the spectral type of our candidate companions. This approach distinguishes substellar objects from background interlopers based on the strength of the 1.4 um water feature robustly observed in MLTY objects but not in reddened background stars - both our candidates show clear evidence of absorption at 1.4 um. If confirmed, these candidate companions would significantly increase the census of young planetary mass companions around extremely young brown dwarfs. These candidate companions are too faint to be observed with ground-based laser guide star adaptive optics (LGS AO) nor is the 1.4 um water feature observable from the ground for such faint objects due to telluric absorption, thus HST is the only telescope in the world suitable for these observations.

Laboratory confirmation of rubella infection in suspected measles cases.

PubMed

Vaidya, Sunil R; Raut, Chandrashekhar G; Jadhav, Santoshkumar M

2016-10-01

As a part of measles outbreak based surveillance undertaken by the World Health Organization India, suspected measles cases were referred for the laboratory diagnosis at National Institute of Virology (NIV) Pune and NIV Unit Bengaluru. Altogether, 4,592 serum samples were referred during 2010-2015 from the States of Karnataka (n = 1,173), Kerala (n = 559), and Maharashtra (n = 2,860). Initially, serum samples were tested in measles IgM antibody EIA and samples with measles negative and equivocal results (n = 1,954) were subjected to rubella IgM antibody detection. Overall, 62.9% (2,889/4,592) samples were laboratory confirmed measles, 27.7% (542/1,954) were laboratory confirmed rubella and remaining 25.2% (1,161/4,592) were negative for measles and rubella. The measles vaccination status was available for 1,206 cases. Among the vaccinated individuals, 50.7% (612/1,206) were laboratory confirmed measles. The contribution of laboratory confirmed measles was 493 (40.8%) from Maharashtra, 90 (7.5%) from Karnataka, and 29 (2.4%) from Kerala. Since, 1/3rd of suspected measles cases were laboratory confirmed rubella, an urgent attention needed to build rubella surveillance in India. Additional efforts are required to rule out other exanthematous disease including Dengue and Chikungunya in measles and rubella negatives. J. Med. Virol. 88:1685-1689, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Quantitative confirmation of diffusion-limited oxidation theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gillen, K.T.; Clough, R.L.

1990-01-01

Diffusion-limited (heterogeneous) oxidation effects are often important for studies of polymer degradation. Such effects are common in polymers subjected to ionizing radiation at relatively high dose rate. To better understand the underlying oxidation processes and to aid in the planning of accelerated aging studies, it would be desirable to be able to monitor and quantitatively understand these effects. In this paper, we briefly review a theoretical diffusion approach which derives model profiles for oxygen surrounded sheets of material by combining oxygen permeation rates with kinetically based oxygen consumption expressions. The theory leads to a simple governing expression involving the oxygenmore » consumption and permeation rates together with two model parameters {alpha} and {beta}. To test the theory, gamma-initiated oxidation of a sheet of commercially formulated EPDM rubber was performed under conditions which led to diffusion-limited oxidation. Profile shapes from the theoretical treatments are shown to accurately fit experimentally derived oxidation profiles. In addition, direct measurements on the same EPDM material of the oxygen consumption and permeation rates, together with values of {alpha} and {beta} derived from the fitting procedure, allow us to quantitatively confirm for the first time the governing theoretical relationship. 17 refs., 3 figs.« less

XPS-nanocharacterization of organic layers electrochemically grafted on the surface of SnO2 thin films to produce a new hybrid material coating

NASA Astrophysics Data System (ADS)

Drevet, R.; Dragoé, D.; Barthés-Labrousse, M. G.; Chaussé, A.; Andrieux, M.

2016-10-01

This work presents the synthesis and the characterization of hybrid material thin films obtained by the combination of two processes. The electrochemical grafting of organic layers made of carboxyphenyl moieties is carried out from the reduction of a diazonium salt on tin dioxide (SnO2) thin films previously deposited on Si substrates by metal organic chemical vapor deposition (MOCVD). Since the MOCVD experimental parameters impact the crystal growth of the SnO2 layer (i.e. its morphology and its texturation), various electrochemical grafting models can occur, producing different hybrid materials. In order to evidence the efficiency of the electrochemical grafting of the carboxyphenyl moieties, X-ray Photoelectron Spectroscopy (XPS) is used to characterize the first nanometers in depth of the synthesized hybrid material layer. Then three electrochemical grafting models are proposed.

Synthesis of TiO2/functionalized graphene sheets (FGSs) nanocomposites in super critical CO2

NASA Astrophysics Data System (ADS)

Farhangi, Nasrin; Medina-Gonzalez, Yaocihuatl; Chen, Bo; Charpentier, Paul A.

2010-06-01

Highly ordered TiO2 nanowire arrays were prepared on the surface of Functionalized Graphene sheets (FGSs) by solgel method using titanium isopropoxide monomer with acetic acid as the polycondensation agent in the green solvent, supercritical carbon dioxide (sc-CO2). Morphology of synthesized materials was studied by SEM and TEM. Optical properties of the nanocomposites studied by UV spectroscopy which showed high absorption in visible area as well as reduction in their band gap compared to TiO2. By high resolution XPS, chelating bidentate structure of TiO2 with carboxylic group on the surface of graphene sheets can be confirmed. Improvement in the optical properties of the synthesized composites compared to TiO2 alone was confirmed by photocurrent measurements.

75 FR 10413 - New Animal Drug Applications; Confirmation of Effective Date

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

.... FDA-2009-N-0436] New Animal Drug Applications; Confirmation of Effective Date AGENCY: Food and Drug Administration, HHS. ACTION: Direct final rule; confirmation of effective date. SUMMARY: The Food and Drug Administration (FDA) is confirming the effective date of March 8, 2010, for the final rule that appeared in the...

Confirmation of an exoplanet using the transit color signature: Kepler-418b, a blended giant planet in a multiplanet system

NASA Astrophysics Data System (ADS)

Tingley, B.; Parviainen, H.; Gandolfi, D.; Deeg, H. J.; Palle, E.; Montañés Rodriguez, P.; Murgas, F.; Alonso, R.; Bruntt, H.; Fridlund, M.

2014-07-01

Aims: We announce confirmation of Kepler-418b, one of two proposed planets in this system. This is the first confirmation of an exoplanet based primarily on the transit color signature technique. Methods: We used the Kepler public data archive combined with multicolor photometry from the Gran Telescopio de Canarias and radial velocity follow-up using FIES at the Nordic Optical Telescope for confirmation. Results: We report a confident detection of a transit color signature that can only be explained by a compact occulting body, entirely ruling out a contaminating eclipsing binary, a hierarchical triple, or a grazing eclipsing binary. Those findings are corroborated by our radial velocity measurements, which put an upper limit of ~1 MJup on the mass of Kepler-418b. We also report that the host star is significantly blended, confirming the ~10% light contamination suspected from the crowding metric in the Kepler light curve measured by the Kepler team. We report detection of an unresolved light source that contributes an additional ~30% to the target star, which would not have been detected without multicolor photometric analysis. The resulting planet-star radius ratio is 0.110 ± 0.0025, more than 25% more than the 0.087 measured by Kepler leading to a radius of 1.20 ± 0.16 RJup instead of the 0.94 RJup measured by the Kepler team. Conclusions: This is the first confirmation of an exoplanet candidate based primarily on the transit color signature, demonstrating that this technique is viable from ground for giant planets. It is particularly useful for planets with long periods such as Kepler-418b, which tend to have long transit durations. While this technique is limited to candidates with deep transits from the ground, it may be possible to confirm earth-like exoplanet candidates with a few hours of observing time with an instrument like the James Webb Space Telescope. Additionally, multicolor photometric analysis of transits can reveal unknown stellar neighbors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaspar, Tiffany C.; Sushko, Peter V.; Bowden, Mark E.

Epitaxial thin films of Cr2-xTixO3 were deposited by oxygen-plasma-assisted molecular beam epitaxy (OPA-MBE) for 0.04 ≤ x ≤ 0.26. Ti speciation is verified by both x-ray photoelectron spectroscopy (XPS) and Ti K-edge x-ray absorption near-edge spectroscopy (XANES) to be Ti4+. Substitution of Ti for Cr in the corundum lattice is confirmed by modeling of the Ti K-edge extended x-ray absorption fine structure (EXAFS). Room temperature electrical transport measurements confirm the highly insulating nature of Ti-doped Cr2O3, despite the presence of aliovalent Ti4+. The resistivity of highly pure, undoped Cr2O3 was measured to be three orders of magnitude higher than formore » Ti-doped Cr2O3. Although the formation of Cr vacancies in Ti-doped Cr2O3 is found by density functional theory (DFT) calculations to be the energetically preferable defect compensation mechanism to maintain charge neutrality, an analysis of the XPS and EXAFS data reveal the presence of both Cr vacancies and oxygen interstitials at intermediate and high Ti concentrations, with a weak trend towards Cr vacancies as the Ti concentration increases. At low Ti concentrations, a strong dependence of the XPS Ti 2p core level peak width on concentration is observed. This dependence is attributed to the presence of widely spaced Ti dopants, which renders compensation of two or three Ti by a single oxygen interstitial or Cr vacancy, respectively, less probable. Instead, defect clusters of unknown type occur, although they may involve Cr vacancies. The defect compensation model developed here provides insight into previous, conflicting reports of n-type versus p-type conductivity in Ti-doped Cr2O3 at high temperature, and will inform future studies to exploit the wide variety of electronic and magnetic properties of corundum-structure oxides.« less

Characterization of Au/PbTi0.5Fe0.5O3/Si structure for possible multiferroic based non-volatile memory applications

NASA Astrophysics Data System (ADS)

Nawaz, S.; Roy, S.; Tulapurkar, A. A.; Palkar, V. R.

2017-03-01

Magnetoelectric multiferroic PbTi0.5Fe0.5O3 films are deposited on a ⟨100⟩ conducting p-Si substrate without any buffer layer by using pulsed laser deposition and characterized for possible non-volatile memory applications. Their crystalline structure and surface morphology were characterized by using x-ray diffraction and AFM techniques. HRTEM was employed to determine the film-substrate interface. The electronic structure of the film was investigated by XPS, and no signature of metal was found for all the elements. The chemical shift of the Ti 2p XPS peak is attributed to the replacement of Ti with Fe in the PbTiO3 matrix. Piezoelectric force microscopy (PFM) results indicate the 180° phase shift of ferroelectric polarization. The upward self-polarization phenomenon is also observed in the PFM study. Magnetic and magneto-electric coupling measurements were carried out to confirm the magnetic nature and electro-magnetic coupling characteristics. C-V measurements exhibit clock-wise hysteresis loops with a maximum memory window of 1.2 V and a sweep voltage of ±7 V. This study could influence the fabrication of silicon compatible multiple memory device structures.

Plasma surface cleaning in a microwave plasma source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, C.C.; Nelson, W.D.; Haselton, H.H.

1994-03-01

A microwave electron cyclotron resonance (ECR) plasma source has been operated to produce reactive plasmas of oxygen and its mixture with argon. Aluminum samples (0.95 cm by 1.9 cm) were coated with thin films (<20 {mu}m in thickness) of Shell Vitrea oil and cleaned by using such reactive plasmas. The plasma cleaning was done in discharge conditions of microwave power up to 1300 W, radio frequency power up to 200 W, biased potential up to 400 V, gas pressures up to 5 mtorr, and operating time up to 35 min. The surface texture of the postcleaned samples has been examinedmore » visually. Mass loss of the samples after plasma cleaning was measured to estimate cleaning rates. Measured clean rates of low-pressure (0.5-mtorr) argon/oxygen plasmas were as high as 2.7 {mu}m/min. X-ray photoelectron spectroscopy (XPS) was used to determine cleanliness of the sample surfaces after plasma cleaning. The XPS study on polished samples confirmed the effectiveness of plasma cleaning in achieving atomic level of surface cleanliness. In this technical memorandum plasma properties, cleaning phenomena, and significant results are reported and discussed.« less

Effects of oxide replacement with fluoride at the CoFeB interface on interface magnetic anisotropy and its voltage control

NASA Astrophysics Data System (ADS)

Pankieiev, Mykhailo; Kita, Koji

2018-05-01

In this paper we report results of improving Co60Fe20B20 interface perpendicular magnetic anisotropy (PMA) by replacing neighbor oxide layer with fluoride one. We expected that fluorine as element with higher than oxide electronegativity could more effectively attract electrons from out-of-plane d orbitals of ferromagnetic, increasing role of in-plane orbitals. By this we wanted to increase PMA and its response to applied voltage bias. Polar magneto-optic Kerr effect measurement show decreasing of out-of-plane magnetic field needed to change magnetization to perpendicular in stacks with oxygen replaced by fluorine as well as increasing of coefficient of response to applied voltage α from < 10 fJ/Vm for CoFeB/Al2O3 interface to 20 fJ/Vm for CoFeB/AlF3/Al2O3 and 22 fJ/Vm for CoFeB/MgF2 stacks. Direct chemical interaction of Co with F was confirmed by x-ray photoelectron spectroscopy (XPS) measurement of Co2p core level region. Moreover angular-resolved XPS showed that F tends to stay at CoFeB interface rather than diffuse out of it.

SiGe derivatization by spontaneous reduction of aryl diazonium salts

NASA Astrophysics Data System (ADS)

Girard, A.; Geneste, F.; Coulon, N.; Cardinaud, C.; Mohammed-Brahim, T.

2013-10-01

Germanium semiconductors have interesting properties for FET-based biosensor applications since they possess high surface roughness allowing the immobilization of a high amount of receptors on a small surface area. Since SiGe combined low cost of Si and intrinsic properties of Ge with high mobility carriers, we focused the study on this particularly interesting material. The comparison of the efficiency of a functionalization process involving the spontaneous reduction of diazonium salts is studied on Si(1 0 0), SiGe and Ge semiconductors. XPS analysis of the functionalized surfaces reveals the presence of a covalent grafted layer on all the substrates that was confirmed by AFM. Interestingly, the modified Ge derivatives have still higher surface roughness after derivatization. To support the estimated thickness by XPS, a step measurement of the organic layers is done by AFM or by profilometer technique after a O2 plasma etching of the functionalized layer. This original method is well-adapted to measure the thickness of thin organic films on rough substrates such as germanium. The analyses show a higher chemical grafting on SiGe substrates compared with Si and Ge semiconductors.

Surface modification of malachite with ethanediamine and its effect on sulfidization flotation

NASA Astrophysics Data System (ADS)

Feng, Qicheng; Zhao, Wenjuan; Wen, Shuming

2018-04-01

Ethanediamine was used to modify the mineral surface of malachite to improve its sulfidization and flotation behavior. The activation mechanism was investigated by adsorption experiments, X-ray photoelectron spectroscopy (XPS) analysis, and zeta potential measurements. Microflotation experiments showed that the flotation recovery of malachite was enhanced after the pretreatment of the mineral particles with ethanediamine prior to the addition of Na2S. Adsorption tests revealed that numerous sulfide ion species in the pulp solution were transferred onto the mineral surface through the formation of more copper sulfide species. This finding was confirmed by the results of the XPS measurements. Ethanediamine modification not only increased the contents of copper sulfide species on the malachite surface but also enhanced the reactivity of the sulfidization products. During sulfidization, Cu(II) species on the mineral surface were reduced into Cu(I) species, and the percentages of S22- and Sn2- relative to the total S increased after modification, resulting in increased surface hydrophobicity. The results of zeta potential measurements showed that the ethanediamine-modified mineral surface adsorbed with more sulfide ion species was advantageous to the attachment of xanthate species, thereby improving malachite floatability. The proposed ethanediamine modification followed by sulfidization xanthate flotation exhibits potential for industrial application.

Definite (microbiologically confirmed) tuberculous meningitis: predictors and prognostic impact.

PubMed

Jha, Sneh Kumar; Garg, Ravindra Kumar; Jain, Amita; Malhotra, Hardeep Singh; Verma, Rajesh; Sharma, Praveen Kumar

2015-12-01

Microbiological confirmation cannot be obtained in approximately two-third patients with tuberculous meningitis. In this study, we sought to identify epidemiological, clinical, cerebrospinal fluid, and imaging parameters that could indicate the possibility of microbiological confirmation among patients with suspected tuberculous meningitis. In this prospective observational study, patients with tuberculous meningitis were evaluated for clinical, laboratory (cerebrospinal fluid microscopy, culture, and polymerase chain reaction), and neuroimaging parameters. All patients received anti-tuberculosis drugs and corticosteroids. The patients were followed for a period of 6 months. Among 118 cases of tuberculous meningitis, there were 43 (36 %) definite (microbiologically confirmed) cases, 59 (50 %) probable and 16 (14 %) possible cases. Among 43 definite cases, tuberculosis polymerase chain reaction (PCR) was positive in 42 (35 %) patients, culture was positive in 1 case and microscopy, after Ziehl-Neelsen staining, was positive in 3 cases. Three factors, modified Barthel index score at admission ≤12 (p = 0.008), cerebrospinal fluid total cell count >100/mm(3) (p = 0.016), and basal exudates on imaging (p = 0.015), were significantly associated with definite tuberculous meningitis. Among 20 patients who died within 6 months, 13 belonged to definite tuberculous meningitis group (p < 0.001). Stage III tuberculous meningitis (p = 0.004), baseline-modified Barthel index score ≤12 (p = 0.013), and positive tuberculosis PCR (p = 0.007) were independently associated with poor outcome on multivariate analysis. Severe disability, cerebrospinal fluid cells >100 mm(3), and basal exudates are significantly related to the presence of microbiologically confirmed definite tuberculous meningitis. Microbiologically confirmed tuberculous meningitis is associated with poorer outcome.

Before-and-After Views Confirm Fresh Craters

NASA Image and Video Library

2014-05-22

These images from the Context Camera on NASA Mars Reconnaissance Orbiter were taken before and after an apparent impact scar appeared in the area in March 2012. Comparing the images confirms that fresh craters appeared during the interval.

Verification testing to confirm VO2max attainment in persons with spinal cord injury.

PubMed

Astorino, Todd A; Bediamol, Noelle; Cotoia, Sarah; Ines, Kenneth; Koeu, Nicolas; Menard, Natasha; Nyugen, Brianna; Olivo, Cassandra; Phillips, Gabrielle; Tirados, Ardreen; Cruz, Gabriela Velasco

2018-01-22

Maximal oxygen uptake (VO 2 max) is a widely used measure of cardiorespiratory fitness, aerobic function, and overall health risk. Although VO 2 max has been measured for almost 100 yr, no standardized criteria exist to verify VO 2 max attainment. Studies document that incidence of 'true' VO 2 max obtained from incremental exercise (INC) can be confirmed using a subsequent verification test (VER). In this study, we examined efficacy of VER in persons with spinal cord injury (SCI). Repeated measures, within-subjects study. University laboratory in San Diego, CA. Ten individuals (age and injury duration = 33.3 ± 10.5 yr and 6.8 ± 6.2 yr) with SCI and 10 able-bodied (AB) individuals (age = 24.1 ± 7.4 yr). Peak oxygen uptake (VO 2 peak) was determined during INC on an arm ergometer followed by VER at 105 percent of peak power output (% PPO). Gas exchange data, heart rate (HR), and blood lactate concentration (BLa) were measured during exercise. Across all participants, VO 2 peak was highly related between protocols (ICC = 0.98) and the mean difference was equal to 0.08 ± 0.11 L/min. Compared to INC, VO 2 peak from VER was not different in SCI (1.30 ± 0.45 L/min vs. 1.31 ± 0.43 L/min) but higher in AB (1.63 ± 0.40 L/min vs. 1.76 ± 0.40 L/min). Data show similar VO 2 peak between incremental and verification tests in SCI, suggesting that VER confirms VO 2 max attainment. However, in AB participants completing arm ergometry, VER is essential to validate appearance of 'true' VO 2 peak.

Confirming Testlet Effects

ERIC Educational Resources Information Center

DeMars, Christine E.

2012-01-01

A testlet is a cluster of items that share a common passage, scenario, or other context. These items might measure something in common beyond the trait measured by the test as a whole; if so, the model for the item responses should allow for this testlet trait. But modeling testlet effects that are negligible makes the model unnecessarily…

Stereotype confirmation concern and fear of negative evaluation among African Americans and Caucasians with social anxiety disorder.

PubMed

Johnson, Suzanne B; Anderson, Page L

2014-05-01

Fear of negative evaluation is a central component of social anxiety. The current study examines the relation between fear of negative evaluation and fears of confirming stereotypes about social groups to which one belongs among people diagnosed with social anxiety disorder. Participants (N=94) with a primary diagnosis of social anxiety disorder who self-identified as either African American (n=41) or Caucasian (n=53) completed standardized self-report measures of stereotype confirmation concerns and fear of negative evaluation. Results from hierarchical logistical regression showed that stereotype confirmation concerns predicted fear of negative evaluation for both racial groups, with greater concern predicting greater fear. This association was moderated by race, B=-.24, t=-2.67, p<.01, such that stereotype confirmation concerns had a stronger association with fear of negative evaluation for Caucasians (b=.38, p<.01) than for African Americans (b=.14, p<.05). This study is the first to directly examine the relation between stereotypes and fear of negative evaluation within a socially anxious sample. Although we cannot identify the specific social group to which each participant's stereotype confirmation concerns apply, this study provides quantitative evidence that the social context within which socially anxious individuals view themselves impacts their fear of negative evaluation and highlights the need for further research in this area. Copyright © 2014 Elsevier Ltd. All rights reserved.

10 CFR 63.132 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Commission. (e) In situ monitoring of the thermomechanical response of the underground facility must be... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Performance Confirmation Program § 63.132... engineered systems and components, must be identified in the performance confirmation plan. (d) These...

10 CFR 63.132 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Commission. (e) In situ monitoring of the thermomechanical response of the underground facility must be... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Performance Confirmation Program § 63.132... engineered systems and components, must be identified in the performance confirmation plan. (d) These...

10 CFR 63.132 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Commission. (e) In situ monitoring of the thermomechanical response of the underground facility must be... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Performance Confirmation Program § 63.132... engineered systems and components, must be identified in the performance confirmation plan. (d) These...

10 CFR 60.141 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2012 CFR

2012-01-01

... reported to the Commission. (e) In situ monitoring of the thermomechanical response of the underground... IN GEOLOGIC REPOSITORIES Performance Confirmation Program § 60.141 Confirmation of geotechnical and... needed in design to accommodate actual field conditions encountered. (b) Subsurface conditions shall be...

10 CFR 60.141 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2014 CFR

2014-01-01

... reported to the Commission. (e) In situ monitoring of the thermomechanical response of the underground... IN GEOLOGIC REPOSITORIES Performance Confirmation Program § 60.141 Confirmation of geotechnical and... needed in design to accommodate actual field conditions encountered. (b) Subsurface conditions shall be...

10 CFR 60.141 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2013 CFR

2013-01-01

... reported to the Commission. (e) In situ monitoring of the thermomechanical response of the underground... IN GEOLOGIC REPOSITORIES Performance Confirmation Program § 60.141 Confirmation of geotechnical and... needed in design to accommodate actual field conditions encountered. (b) Subsurface conditions shall be...

10 CFR 63.132 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Commission. (e) In situ monitoring of the thermomechanical response of the underground facility must be... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Performance Confirmation Program § 63.132... engineered systems and components, must be identified in the performance confirmation plan. (d) These...

10 CFR 63.132 - Confirmation of geotechnical and design parameters.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Commission. (e) In situ monitoring of the thermomechanical response of the underground facility must be... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Performance Confirmation Program § 63.132... engineered systems and components, must be identified in the performance confirmation plan. (d) These...

16 CFR 1633.5 - Prototype pooling and confirmation testing requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Prototype pooling and confirmation testing... Prototype pooling and confirmation testing requirements. (a) Prototype pooling. One or more manufacturers may rely on a qualified prototype produced by another manufacturer or prototype developer provided...

Do physicians care about patients with dysphagia? A study on confirming communication.

PubMed

Gustafsson, B; Tibbling, L; Theorell, T

1992-06-01

Thirty-nine patients with longstanding oesophageal dysphagia took part in an interview and a questionnaire study to investigate whether they considered themselves met with interest, respect, understanding and knowledge (felt confirmed) when consulting their physician for the first time (mostly general practitioner), whether non-confirmed patients have any distinguishing attributes, and whether confirmation affects the patient's impression of being helped. Twenty-five of these considered themselves as non-confirmed. There was no difference between the groups as regards sex, age, education, degree of swallowing difficulties and incidence of chest symptoms other than dysphagia. There was a greater fear of cancer (P less than 0.05) and a stronger indirect aggression (P less than 0.05) among the non-confirmed patients. Patients who felt confirmed reported more often that a correct oesophageal diagnosis had been given (P less than 0.05), felt they had received adequate help (P less than 0.001) and experienced improvement in swallowing difficulties (P less than 0.05). It is concluded that patient attributes seem to slightly influence the patients' possibilities of being confirmed, and that confirmation is of great importance for the patient's feeling of being helped and improved.

Psychotherapy of Depression: A Self-Confirmation Model.

ERIC Educational Resources Information Center

Andrews, John D. W.

1989-01-01

Concepts of self-confirmation, interpersonal diagnosis, and prototype construction are used to integrate research and clinical findings concerning depression. Various theoretical accounts and bodies of data that fit within this integrative conceptual framework are examined, and implications for psychotherapy are discussed. (SLD)

Installation Restoration Program. Phase II--Confirmation/Quantification. Stage 1.

DTIC Science & Technology

1985-03-01

four phases. Phase I, Initial Assessment/ Records Search, is designed to identify possible hazardous waste contami- nated sites and potential...7 71 -. - - IL’ -, 1% 33 AihlIII Is 33 n~iL t iiC UII! ii CL C LU 1-3, Phase II, Confirmation and Quantification, is designed to confirm the...additional monitoring data upon which design of mitigative actions are based. In Phase III, Technology Base Development, appropriate technology is selected and

Macroscopic and microscopic investigation of Ni(II) sequestration on diatomite by batch, XPS, and EXAFS techniques.

PubMed

Sheng, Guodong; Yang, Shitong; Sheng, Jiang; Hu, Jun; Tan, Xiaoli; Wang, Xiangke

2011-09-15

Sequestration of Ni(II) on diatomite as a function of time, pH, and temperature was investigated by batch, XPS, and EXAFS techniques. The ionic strength-dependent sorption at pH < 7.0 was consistent with outer-sphere surface complexation, while the ionic strength-independent sorption at pH = 7.0-8.6 was indicative of inner-sphere surface complexation. EXAFS results indicated that the adsorbed Ni(II) consisted of ∼6 O at R(Ni-O) ≈ 2.05 Å. EXAFS analysis from the second shell suggested that three phenomena occurred at the diatomite/water interface: (1) outer-sphere and/or inner-sphere complexation; (2) dissolution of Si which is the rate limiting step during Ni uptake; and (3) extensive growth of surface (co)precipitates. Under acidic conditions, outer-sphere complexation is the main mechanism controlling Ni uptake, which is in good agreement with the macroscopic results. At contact time of 1 h or 1 day or pH = 7.0-8.0, surface coprecipitates occur concurrently with inner-sphere complexes on diatomite surface, whereas at contact time of 1 month or pH = 10.0, surface (co)precipitates dominate Ni uptake. Furthermore, surface loading increases with temperature increasing, and surface coprecipitates become the dominant mechanism at elevated temperature. The results are important to understand Ni interaction with minerals at the solid-water interface, which is helpful to evaluate the mobility of Ni(II) in the natural environment.

Fear-related confirmation bias in children: a comparison between neutral- and dangerous-looking animals.

PubMed

Dibbets, Pauline; Fliek, Lorraine; Meesters, Cor

2015-06-01

The purpose of this study was to examine confirmation bias in children without explicitly inducing fear. Eighty non-clinical children (7-13 years) were shown pictures of a neutral animal (quokka) and two dangerous-looking animals (aye aye and possum). For each animal, levels of perceived fear, threat and request for additional threatening or non-threatening information were obtained. A behavioral approach test (BAT) was included as behavioral measure of fear. The results indicated that the aye aye and possum were rated as more threatening and fearful than the quokka. For the aye aye and possum higher fear levels coincided with search for more threatening than non-threatening information. This pattern was absent in non-fearful children and for the non-threatening quokka. During the BAT the quokka was more often approached first compared to the aye aye and possum. Our findings suggest that confirmation bias in children can be observed without using verbal fear induction.

Collective opinion formation model under Bayesian updating and confirmation bias

NASA Astrophysics Data System (ADS)

Nishi, Ryosuke; Masuda, Naoki

2013-06-01

We propose a collective opinion formation model with a so-called confirmation bias. The confirmation bias is a psychological effect with which, in the context of opinion formation, an individual in favor of an opinion is prone to misperceive new incoming information as supporting the current belief of the individual. Our model modifies a Bayesian decision-making model for single individuals [M. Rabin and J. L. Schrag, Q. J. Econ.0033-553310.1162/003355399555945 114, 37 (1999)] for the case of a well-mixed population of interacting individuals in the absence of the external input. We numerically simulate the model to show that all the agents eventually agree on one of the two opinions only when the confirmation bias is weak. Otherwise, the stochastic population dynamics ends up creating a disagreement configuration (also called polarization), particularly for large system sizes. A strong confirmation bias allows various final disagreement configurations with different fractions of the individuals in favor of the opposite opinions.

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

NASA Technical Reports Server (NTRS)

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.

A female Viking warrior confirmed by genomics

PubMed Central

Kjellström, Anna; Zachrisson, Torun; Krzewińska, Maja; Sobrado, Veronica; Price, Neil; Günther, Torsten; Jakobsson, Mattias; Götherström, Anders; Storå, Jan

2017-01-01

Abstract Objectives The objective of this study has been to confirm the sex and the affinity of an individual buried in a well‐furnished warrior grave (Bj 581) in the Viking Age town of Birka, Sweden. Previously, based on the material and historical records, the male sex has been associated with the gender of the warrior and such was the case with Bj 581. An earlier osteological classification of the individual as female was considered controversial in a historical and archaeological context. A genomic confirmation of the biological sex of the individual was considered necessary to solve the issue. Materials and methods Genome‐wide sequence data was generated in order to confirm the biological sex, to support skeletal integrity, and to investigate the genetic relationship of the individual to ancient individuals as well as modern‐day groups. Additionally, a strontium isotope analysis was conducted to highlight the mobility of the individual. Results The genomic results revealed the lack of a Y‐chromosome and thus a female biological sex, and the mtDNA analyses support a single‐individual origin of sampled elements. The genetic affinity is close to present‐day North Europeans, and within Sweden to the southern and south‐central region. Nevertheless, the Sr values are not conclusive as to whether she was of local or nonlocal origin. Discussion The identification of a female Viking warrior provides a unique insight into the Viking society, social constructions, and exceptions to the norm in the Viking time‐period. The results call for caution against generalizations regarding social orders in past societies. PMID:28884802

Child Sexual Abuse Confirmed by Forensic Examination in Salvador, Bahia, Brazil.

PubMed

Silva, Welington Dos Santos; Barroso-Junior, Ubirajara de Oliveira

2017-03-01

Child sexual abuse is a worldwide public health issue. The objective of this study was to describe the demographic and clinical characteristics of children in cases of sexual abuse confirmed by material evidence at forensic examination. Cases of children younger than 12 years examined for suspected sexual abuse at the Institute of Forensic Medicine in Salvador, Bahia, Brazil, were reviewed retrospectively. The period evaluated was between 2005 and 2010. The inclusion criterion was the coroner's confirmation of sexual abuse based on material evidence. The mean age of the children in whom sexual abuse was confirmed was 8.2 (SD, 2.9) years, and 208 cases were female (83.9%). In 94% of the cases, the reason for carrying out the forensic examination was a report of sexual abuse. Less than 1% of the aggressors were female. A ruptured hymen was the finding that confirmed sexual abuse in 172 cases, corresponding to 83% of cases in girls. There were 2 cases of pregnancy. Recent anal or perianal lesions were present in 35 (87.5%) of the confirmed cases involving boys. Laboratory confirmation based on the detection of spermatozoa or prostate-specific antigen occurred in only 4.2% of cases. In all these cases, sample collection was performed within 24 hours of the alleged abuse. Thus, in the majority of cases with material evidence of sexual abuse, the confirmation criteria consisted of a ruptured hymen and recent perianal lesions.

Selective determination of gold(III) ion using CuO microsheets as a solid phase adsorbent prior by ICP-OES measurement.

PubMed

Rahman, Mohammed M; Khan, Sher Bahadar; Marwani, Hadi M; Asiri, Abdullah M; Alamry, Khalid A; Al-Youbi, Abdulrahman O

2013-01-30

We have prepared calcined CuO microsheets (MSs) by a wet-chemical process using reducing agents in alkaline medium and characterized by UV/vis., fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM) etc. The detailed structural, compositional, and optical characterizations of the MSs were evaluated by XRD pattern, FT-IR, X-ray photoelectron spectroscopy (XPS), and UV-vis spectroscopy, respectively which confirmed that the obtained MSs are well-crystalline CuO and possessed good optical properties. The CuO MSs morphology was investigated by FESEM, which confirmed that the calcined nanomaterials were sheet-shaped and grown in large-quantity. Here, the efficiency of the CuO MS was applied for a selective adsorption of gold(III) ion prior to its detection by inductively coupled plasma-optical emission spectrometry (ICP-OES). The selectivity of CuO MSs towards various metal ions, including Au(III), Cd(II), Co(II), Cr(III), Fe(III), Pd(II), and Zn(II) was analyzed. Based on the adsorption isotherm study, it was confirmed that the selectivity of MSs phase was mostly towards Au(III) ion. The static adsorption capacity for Au(III) was calculated to be 57.0 mg g(-1). From Langmuir adsorption isotherm, it was confirmed that the adsorption process was mainly monolayer-adsorption onto a surface containing a finite number of adsorption sites. Copyright © 2012 Elsevier B.V. All rights reserved.

Enhancing Electrochemical Water-Splitting Kinetics by Polarization-Driven Formation of Near-Surface Iron(0): An In Situ XPS Study on Perovskite-Type Electrodes**

PubMed Central

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

Using Daily Horoscopes To Demonstrate Expectancy Confirmation.

ERIC Educational Resources Information Center

Munro, Geoffrey D.; Munro, James E.

2000-01-01

Describes a classroom demonstration that uses daily horoscopes to show the effect that expectation can have on judgment. Addresses the preparation, procedure, and results of the demonstration, and student evaluations. States that the demonstration appears to be effective for teaching students about expectancy confirmation. (CMK)

Tunable Stoichiometry of BCxNy Thin Films Through Multitarget Pulsed Laser Deposition Monitored via In Situ Ellipsometry (Postprint)

DTIC Science & Technology

2014-02-05

X - ray photoelectron spectroscopy (XPS), Raman spectroscopy , and atomic ...calculate thickness, n and k. X - ray photoelectron spectroscopy (XPS), Raman spectroscopy , and atomic force microscopy (AFM) were all performed on each of the... X - ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to measure and compare the composition of the films.6 In this paper,

Tektite ablation - Some confirming calculations.

NASA Technical Reports Server (NTRS)

O'Keefe, J. A., III; Silver, A. D.; Cameron, W. S.; Adams , E. W.; Warmbrod, J. D.

1973-01-01

The calculation of tektite ablation has been redone, taking into account transient effects, internal radiation, melting and nonequilibrium vaporization of the glass, and the drag effect of the flanges. It is found that the results confirm the earlier calculations of Chapman and his group and of Adams and his co-workers. The general trend of the results is not sensitive to reasonable changes of the physical parameters. The ablation is predominantly by melting rather than by vaporization at all velocities up to 11 km/sec; this is surprising in view of the lack of detectable melt flow in most tektites. Chemical effects have not been considered.

Confirmation of shutdown cooling effects

NASA Astrophysics Data System (ADS)

Sato, Kotaro; Tabuchi, Masato; Sugimura, Naoki; Tatsumi, Masahiro

2015-12-01

After the Fukushima accidents, all nuclear power plants in Japan have gradually stopped their operations and have long periods of shutdown. During those periods, reactivity of fuels continues to change significantly especially for high-burnup UO2 fuels and MOX fuels due to radioactive decays. It is necessary to consider these isotopic changes precisely, to predict neutronics characteristics accurately. In this paper, shutdown cooling (SDC) effects of UO2 and MOX fuels that have unusual operation histories are confirmed by the advanced lattice code, AEGIS. The calculation results show that the effects need to be considered even after nuclear power plants come back to normal operation.

Experimental Confirmation of Lenz's Law

ERIC Educational Resources Information Center

Mayer, V. V.; Varaksina, E. I.

2017-01-01

The paper presents a series of experiments that demonstrate the phenomenon of electromagnetic induction. These make it possible to determine the direction of the induced current and so confirm Lenz's Law. The simple experiments can be reproduced in a school laboratory and can be recommended for students' project activity.

A female Viking warrior confirmed by genomics.

PubMed

Hedenstierna-Jonson, Charlotte; Kjellström, Anna; Zachrisson, Torun; Krzewińska, Maja; Sobrado, Veronica; Price, Neil; Günther, Torsten; Jakobsson, Mattias; Götherström, Anders; Storå, Jan

2017-12-01

The objective of this study has been to confirm the sex and the affinity of an individual buried in a well-furnished warrior grave (Bj 581) in the Viking Age town of Birka, Sweden. Previously, based on the material and historical records, the male sex has been associated with the gender of the warrior and such was the case with Bj 581. An earlier osteological classification of the individual as female was considered controversial in a historical and archaeological context. A genomic confirmation of the biological sex of the individual was considered necessary to solve the issue. Genome-wide sequence data was generated in order to confirm the biological sex, to support skeletal integrity, and to investigate the genetic relationship of the individual to ancient individuals as well as modern-day groups. Additionally, a strontium isotope analysis was conducted to highlight the mobility of the individual. The genomic results revealed the lack of a Y-chromosome and thus a female biological sex, and the mtDNA analyses support a single-individual origin of sampled elements. The genetic affinity is close to present-day North Europeans, and within Sweden to the southern and south-central region. Nevertheless, the Sr values are not conclusive as to whether she was of local or nonlocal origin. The identification of a female Viking warrior provides a unique insight into the Viking society, social constructions, and exceptions to the norm in the Viking time-period. The results call for caution against generalizations regarding social orders in past societies. © 2017 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Serial Head and Brain Imaging of 17 Fetuses With Confirmed Zika Virus Infection in Colombia, South America.

PubMed

Parra-Saavedra, Miguel; Reefhuis, Jennita; Piraquive, Juan Pablo; Gilboa, Suzanne M; Badell, Martina L; Moore, Cynthia A; Mercado, Marcela; Valencia, Diana; Jamieson, Denise J; Beltran, Mauricio; Sanz-Cortes, Magda; Rivera-Casas, Ana Maria; Yepez, Mayel; Parra, Guido; Ospina Martinez, Martha; Honein, Margaret A

2017-07-01

To evaluate fetal ultrasound and magnetic resonance imaging findings among a series of pregnant women with confirmed Zika virus infection to evaluate the signs of congenital Zika syndrome with respect to timing of infection. We conducted a retrospective case series of pregnant women referred to two perinatal clinics in Barranquilla and Ibagué, Colombia, who had findings consistent with congenital Zika syndrome and Zika virus infection confirmed in maternal, fetal, or neonatal samples. Serial ultrasound measurements, fetal magnetic resonance imaging results, laboratory results, and perinatal outcomes were evaluated. We describe 17 cases of confirmed prenatal maternal Zika virus infection with adverse fetal outcomes. Among the 14 symptomatic women, the median gestational age for maternal Zika virus symptoms was 10 weeks (range 7-14 weeks of gestation). The median time between Zika virus symptom onset and microcephaly (head circumference less than 3 standard deviations below the mean) was 18 weeks (range 15-24 weeks). The earliest fetal head circumference measurement consistent with microcephaly diagnosis was at 24 weeks of gestation. The earliest sign of congenital Zika syndrome was talipes equinovarus, which in two patients was noted first at 19 weeks of gestation. Common findings on fetal magnetic resonance imaging were microcephaly, ventriculomegaly, polymicrogyria, and calcifications. Our analysis suggests a period of at least 15 weeks between maternal Zika virus infection in pregnancy and development of microcephaly and highlights the importance of serial and detailed neuroimaging.

12 CFR 551.80 - How do I provide a registered broker-dealer confirmation?

Code of Federal Regulations, 2010 CFR

2010-01-01

... providing the customer with a registered broker-dealer confirmation, you must provide the confirmation by having the registered broker-dealer send the confirmation directly to the customer or by sending a copy of the registered broker-dealer's confirmation to the customer within one business day after you...

Surface studies of low molecular weight photolysis products from UV-ozone oxidised polystyrene

NASA Astrophysics Data System (ADS)

Davidson, M. R.; Mitchell, S. A.; Bradley, R. H.

2005-05-01

The production of low molecular weight oxidised material during UV-ozone treatment of polystyrene has been studied by XPS, GC-MS, FTIR and UV/visible spectroscopy. XPS analysis of the oxidised polystyrene surfaces before and after washing with water or methanol indicates that the removal of oxidation products and the surface that remains after washing is strongly dependent on the choice of solvent. Methanol washing removes a greater proportion of the more highly oxidised carbonyl and carboxyl groups resulting in a surface with a lower oxygen content than that remaining after water washing. Extended exposure to UV-ozone treatment reveals a two-stage oxidation process with mono-substituted benzene rings such as benzaldehyde, acetophenone and benzoic acid being produced at exposure times less than 15 min. Compounds, more typical of those formed via dehydration reactions of existing oxidised species, are produced at longer exposure times. UV-visible spectroscopy and Fourier transform infrared spectroscopy also confirm the presence of carboxylic acid, aromatic ketones and esters. Measurements of water contact angle on a 10 min treated surface reveals that methanol washing produces a more hydrophilic surface than water washing, the resulting water contact angles being 47° and 62° respectively. Ageing of methanol washed surfaces for 24 h leads to a recovery of the water contact angle back to 62° which suggests some form of post-washing surface relaxation process. Since XPS analyses show no increase in the oxygen concentration of the methanol washed surfaces after a 24 h ageing period, the increase in contact angle found with ageing is attributed to the reorientation of very near-surface functional groups i.e. within the XPS sampling depth.

Theory-Led Confirmation Bias and Experimental Persona

ERIC Educational Resources Information Center

Allen, Michael

2011-01-01

Questionnaire and interview findings from a survey of three Year 8 (ages 12-13 years) science practical lessons (n = 52) demonstrate how pupils' data collection and inference making were sometimes biased by desires to confirm a personal theory. A variety of behaviours are described where learners knowingly rejected anomalies, manipulated…

Electronic structure study of wide band gap magnetic semiconductor (La{sub 0.6}Pr{sub 0.4}){sub 0.65}Ca{sub 0.35}MnO{sub 3} nanocrystals in paramagnetic and ferromagnetic phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dwivedi, G. D.; Chou, H.; Yang, K. S.

2016-04-25

X-ray circular magnetic dichroism (XMCD), X-ray photoemission spectroscopy (XPS), and ultraviolet photoemission spectroscopy (UPS) techniques were used to study the electronic structure of nanocrystalline (La{sub 0.6}Pr{sub 0.4}){sub 0.65}Ca{sub 0.35}MnO{sub 3} near Fermi-level. XMCD results indicate that Mn{sup 3+} and Mn{sup 4+} spins are aligned parallel to each other at 20 K. The low M-H hysteresis curve measured at 5 K confirms ferromagnetic ordering in the (La{sub 0.6}Pr{sub 0.4}){sub 0.65}Ca{sub 0.35}MnO{sub 3} system. The low temperature valence band XPS indicates that coupling between Mn3d and O2p is enhanced and the electronic states near Fermi-level have been suppressed below T{sub C}. The valence bandmore » UPS also confirms the suppression of electronic states near Fermi-level below Curie temperature. UPS near Fermi-edge shows that the electronic states are almost absent below 0.5 eV (at 300 K) and 1 eV (at 115 K). This absence clearly demonstrates the existence of a wide band-gap in the system since, for hole-doped semiconductors, the Fermi-level resides just above the valence band maximum.« less

Health Risk of Escherichia coli O157:H7 in Drinking Water and Meat and Meat Products and Vegetables to Diarrhoeic Confirmed and Non-Confirmed HIV/AIDS Patients

NASA Astrophysics Data System (ADS)

Abong`O, B. O.; Momba, M. N. B.; Rodda, N.

The current study explored the health risk of E. coli O157:H7 to diarrhoeic confirmed and non-confirmed HIV/AIDS patients due to their exposure to presumed ingestion of water, meat products and vegetables ostensibly contaminated with E. coli O157:H7. Strains of E. coli O157:H7 were isolated by enrichment culture and on Cefixime-Telurite Sorbitol MacConkey agar. Average counts of presumptive E. coli O157 were used for dose-response assessment. Probability of infection to confirmed and non-confirmed HIV/AIDS patients was 20 and 27% from meat and meat products, 21% and 15% from vegetables and 100% due to ingestion of 1500 mL person-1 day-1 of water. Drinking water had higher probability of transmitting E. coli O157:H7 infections than meat and meat products and vegetables. Probability of E. coli O157:H7 infections were high for confirmed HIV/AIDS patients than for non-confirmed patients. Water and foods consumed by HIV/AIDS patients should be safe of any microbial contaminants, these waters and foods should as well be investigated for other enteric pathogens to establish their safety.

Synthesis and properties of nanocrystalline copper indium oxide thin films deposited by Rf magnetron sputtering.

PubMed

Singh, Mandeep; Singh, V N; Mehta, B R

2008-08-01

Nanocrystalline copper indium oxide (CuInO2) thin films with particle size ranging from 25 nm to 71 nm have been synthesized from a composite target using reactive Rf magnetron sputtering technique. X-ray photoelectron spectroscopy (XPS) combined with glancing angle X-ray diffraction (GAXRD) analysis confirmed the presence of delafossite CuInO2 phase in these films. The optical absorption studies show the presence of two direct band gaps at 3.3 and 4.3 eV, respectively. The resistance versus temperature measurements show thermally activated hopping with activation energy of 0.84 eV to be the conduction mechanism.

Low temperature synthesis of hexagonal ZnO nanorods and their hydrogen sensing properties

NASA Astrophysics Data System (ADS)

Qurashi, Ahsanulhaq; Faiz, M.; Tabet, N.; Alam, Mir Waqas

2011-08-01

The growth of hexagonal ZnO nanorods was demonstrated by low temperature chemical synthesis approach. X-ray diffraction (XRD) analysis revealed a wurtzite hexagonal structure of the ZnO nanorods. The optical properties were measured by UV-vis spectrophotometer at room temperature. X-ray photoelectron spectroscopy (XPS) confirmed high purity of the ZnO nanorods. The hydrogen sensor made of the ZnO nanorods showed reversible response. The hydrogen gas tests were carried out in presence of ambient air and the influence of operation temperature on the hydrogen gas sensing property of ZnO nanorods was also investigated.

Pupillary Responses to Robotic and Human Emotions: The Uncanny Valley and Media Equation Confirmed.

PubMed

Reuten, Anne; van Dam, Maureen; Naber, Marnix

2018-01-01

Physiological responses during human-robots interaction are useful alternatives to subjective measures of uncanny feelings for nearly humanlike robots (uncanny valley) and comparable emotional responses between humans and robots (media equation). However, no studies have employed the easily accessible measure of pupillometry to confirm the uncanny valley and media equation hypotheses, evidence in favor of the existence of these hypotheses in interaction with emotional robots is scarce, and previous studies have not controlled for low level image statistics across robot appearances. We therefore recorded pupil size of 40 participants that viewed and rated pictures of robotic and human faces that expressed a variety of basic emotions. The robotic faces varied along the dimension of human likeness from cartoonish to humanlike. We strictly controlled for confounding factors by removing backgrounds, hair, and color, and by equalizing low level image statistics. After the presentation phase, participants indicated to what extent the robots appeared uncanny and humanlike, and whether they could imagine social interaction with the robots in real life situations. The results show that robots rated as nearly humanlike scored higher on uncanniness, scored lower on imagined social interaction, evoked weaker pupil dilations, and their emotional expressions were more difficult to recognize. Pupils dilated most strongly to negative expressions and the pattern of pupil responses across emotions was highly similar between robot and human stimuli. These results highlight the usefulness of pupillometry in emotion studies and robot design by confirming the uncanny valley and media equation hypotheses.

Pupillary Responses to Robotic and Human Emotions: The Uncanny Valley and Media Equation Confirmed

PubMed Central

Reuten, Anne; van Dam, Maureen; Naber, Marnix

2018-01-01

Physiological responses during human–robots interaction are useful alternatives to subjective measures of uncanny feelings for nearly humanlike robots (uncanny valley) and comparable emotional responses between humans and robots (media equation). However, no studies have employed the easily accessible measure of pupillometry to confirm the uncanny valley and media equation hypotheses, evidence in favor of the existence of these hypotheses in interaction with emotional robots is scarce, and previous studies have not controlled for low level image statistics across robot appearances. We therefore recorded pupil size of 40 participants that viewed and rated pictures of robotic and human faces that expressed a variety of basic emotions. The robotic faces varied along the dimension of human likeness from cartoonish to humanlike. We strictly controlled for confounding factors by removing backgrounds, hair, and color, and by equalizing low level image statistics. After the presentation phase, participants indicated to what extent the robots appeared uncanny and humanlike, and whether they could imagine social interaction with the robots in real life situations. The results show that robots rated as nearly humanlike scored higher on uncanniness, scored lower on imagined social interaction, evoked weaker pupil dilations, and their emotional expressions were more difficult to recognize. Pupils dilated most strongly to negative expressions and the pattern of pupil responses across emotions was highly similar between robot and human stimuli. These results highlight the usefulness of pupillometry in emotion studies and robot design by confirming the uncanny valley and media equation hypotheses. PMID:29875722

[Cutaneous gnathostomiasis, first confirmed case in Colombia].

PubMed

Jurado, Leonardo F; Palacios, Diana M; López, Rocío; Baldión, Margarita; Matijasevic, Eugenio

2015-01-01

Gnathostomiasis is a parasitic zoonosis caused by some species of helminthes belonging to the genus Gnathostoma . It has a wide clinical presentation and its diagnosis is a challenge. Tropical and subtropical countries are endemic, and its transmission is associated with eating raw or undercooked meat from fresh water animals. Increasing global tourism and consuming exotic foods have produced a noticeable rise in cases of the disease in the last decades. However, in our country, there has not been any confirmed case of gnathostomiasis previously reported. We present the case of a 63-year-old Colombian man with an international travel history, who presented with gastrointestinal symptoms. During the hospital stay, he developed a cutaneous lesion on the upper right abdominal quadrant, where later, a larva was found. A morphological study allowed us to identify it as Gnathostoma spinigerum . As such, this is the first report of an imported case of gnathostomiasis confirmed in Colombia. This article describes the principles, etiology, pathogenic cycle and treatment of this disease with special considerations to our patient´s particular features.

CAMS confirmation of previously reported meteor showers

NASA Astrophysics Data System (ADS)

Jenniskens, P.; Nénon, Q.; Gural, P. S.; Albers, J.; Haberman, B.; Johnson, B.; Holman, D.; Morales, R.; Grigsby, B. J.; Samuels, D.; Johannink, C.

2016-03-01

Leading up to the 2015 IAU General Assembly, the International Astronomical Union's Working List of Meteor Showers included 486 unconfirmed showers, showers that are not certain to exist. If confirmed, each shower would provide a record of past comet or asteroid activity. Now, we report that 41 of these are detected in the Cameras for Allsky Meteor Surveillance (CAMS) video-based meteor shower survey. They manifest as meteoroids arriving at Earth from a similar direction and orbit, after removing the daily radiant drift due to Earth's motion around the Sun. These showers do exist and, therefore, can be moved to the IAU List of Established Meteor Showers. This adds to 31 previously confirmed showers from CAMS data. For each shower, finding charts are presented based on 230,000 meteors observed up to March of 2015, calculated by re-projecting the drift-corrected Sun-centered ecliptic coordinates into more familiar equatorial coordinates. Showers that are not detected, but should have, and duplicate showers that project to the same Sun-centered ecliptic coordinates, are recommended for removal from the Working List.

Controllable synthesizing DLC nano structures as a super hydrophobic layer on cotton fabric using a low-cost ethanol electrospray-assisted atmospheric plasma jet.

PubMed

Sohbatzadeh, F; Eshghabadi, M; Mohsenpour, T

2018-06-29

The surface modification of cotton samples was carried out using a liquid (ethanol) electrospray-assisted atmospheric pressure plasma jet. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the successful deposition of diamond like carbon (DLC) nano structures on the cotton surface. The super hydrophobic state of the samples was probed by contact angle measurements. The water repellency of the layers was tuned by controlling the voltage applied to the electrospray electrode. An investigation of the morphological and chemical structures of the samples by field emission scanning microscopy, atomic force microscopy (AFM) and XPS indicated that the physical shape, distribution and amorphization of the DLC structures were successfully adjusted and improved by applying a voltage to the electrospray electrode. Finally wash durability of the best sample was tested for 35 cycles. In this work, the use of a well-developed atmospheric pressure plasma jet for DLC nano structures deposition can enable a promising environmentally friendly and low-cost approach for modifying cotton fabrics for super water-repellent fabric applications.

Fullerene C60 coated silicon nanowires as anode materials for lithium secondary batteries.

PubMed

Arie, Arenst Andreas; Lee, Joong Kee

2012-04-01

A Fullerene C60 film was introduced as a coating layer for silicon nanowires (Si NWs) by a plasma assisted thermal evaporation technique. The morphology and structural characteristics of the materials were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). SEM observations showed that the shape of the nanowire structure was maintained after the C60 coating and the XPS analysis confirmed the presence of the carbon coating layer. The electrochemical characteristics of C60 coated Si NWs as anode materials were examined by charge-discharge tests and electrochemical impedance measurements. With the C60 film coating, Si NW electrodes exhibited a higher initial coulombic efficiency of 77% and a higher specific capacity of 2020 mA h g(-1) after the 30th cycle at a current density of 100 microA cm(-2) with cut-off voltage between 0-1.5 V. These improved electrochemical characteristics are attributed to the presence of the C60 coating layer which suppresses side reaction with the electrolyte and maintains the structural integrity of the Si NW electrodes during cycle tests.

Variation of oxygen content in selected potassium fluorido-oxido-tantalate phases

NASA Astrophysics Data System (ADS)

Boča, Miroslav; Moncoĺ, Ján; Netriová, Zuzana; Velič, Dušan; Jerigová, Monika; Nunney, Tim S.; Baily, Christopher J.; Kubíková, Blanka; Šimko, František; Janderka, Pavel

2011-12-01

The compound K 3[TaO 4]•K 3[TaF 4O 2] crystallises in a tetragonal system (space group I-4) with cell parameters a = 6.2220(3) Å and c = 8.7625(34) Å, respectively. The crystal structure consists of two anions, [TaO 4] 3- and [TaF 4O 2] 3- and cations K +. The tantalum atoms lie in special positions and serve as centres of both anions, which are substitution disorders. XPS measurements confirmed the existence of different binding energies corresponding to the different bonds of Ta sbnd O and Ta sbnd F. Oxygen is bound more strongly in [TaF 4O 2] 3-. By combination of single crystal analysis, XRD, SIMS and XPS it was suggested that previously reported cubic phase K 3TaOF 6 is in fact K 3TaO 2F 4 and previously reported tetragonal phase K 3TaO 2F 4 is in fact K 3[TaO 4]•K 3[TaF 4O 2].

Antimicrobial activity of immobilized lactoferrin and lactoferricin.

PubMed

Chen, Renxun; Cole, Nerida; Dutta, Debarun; Kumar, Naresh; Willcox, Mark D P

2017-11-01

Lactoferrin and lactoferricin were immobilized on glass surfaces via two linkers, 4-azidobenzoic acid (ABA) or 4-fluoro-3-nitrophenyl azide (FNA). The resulting surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The antimicrobial activity of the surfaces was determined using Pseudomonas aeruginosa and Staphylococcus aureus strains by fluorescence microscopy. Lactoferrin and lactoferricin immobilization was confirmed by XPS showing significant increases (p < 0.05) in nitrogen on the glass surface. The immobilization of both proteins slightly increased the overall hydrophobicity of the glass. Both lactoferrin and lactoferricin immobilized on glass significantly (p < 0.05) reduced the numbers of viable bacterial cells adherent to the glass. For P. aeruginosa, the immobilized proteins consistently increased the percentage of dead cells compared to the total cells adherent to the glass surfaces (p < 0.03). Lactoferrin and lactoferricin were successfully immobilized on glass surfaces and showed promising antimicrobial activity against pathogenic bacteria. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2612-2617, 2017. © 2016 Wiley Periodicals, Inc.

Controllable synthesizing DLC nano structures as a super hydrophobic layer on cotton fabric using a low-cost ethanol electrospray-assisted atmospheric plasma jet

NASA Astrophysics Data System (ADS)

Sohbatzadeh, F.; Eshghabadi, M.; Mohsenpour, T.

2018-06-01

The surface modification of cotton samples was carried out using a liquid (ethanol) electrospray-assisted atmospheric pressure plasma jet. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the successful deposition of diamond like carbon (DLC) nano structures on the cotton surface. The super hydrophobic state of the samples was probed by contact angle measurements. The water repellency of the layers was tuned by controlling the voltage applied to the electrospray electrode. An investigation of the morphological and chemical structures of the samples by field emission scanning microscopy, atomic force microscopy (AFM) and XPS indicated that the physical shape, distribution and amorphization of the DLC structures were successfully adjusted and improved by applying a voltage to the electrospray electrode. Finally wash durability of the best sample was tested for 35 cycles. In this work, the use of a well-developed atmospheric pressure plasma jet for DLC nano structures deposition can enable a promising environmentally friendly and low-cost approach for modifying cotton fabrics for super water-repellent fabric applications.

Oxygen partial pressure effects on the RF sputtered p-type NiO hydrogen gas sensors

NASA Astrophysics Data System (ADS)

Turgut, Erdal; Çoban, Ömer; Sarıtaş, Sevda; Tüzemen, Sebahattin; Yıldırım, Muhammet; Gür, Emre

2018-03-01

NiO thin films were grown by Radio Frequency (RF) Magnetron Sputtering method under different oxygen partial pressures, which are 0.6 mTorr, 1.3 mTorr and 2.0 mTorr. The effects of oxygen partial pressures on the thin films were analyzed through Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Hall measurements. The change in the surface morphology of the thin films has been observed with the SEM and AFM measurements. While nano-pyramids have been obtained on the thin film grown at the lowest oxygen partial pressure, the spherical granules lower than 60 nm in size has been observed for the samples grown at higher oxygen partial pressures. The shift in the dominant XRD peak is realized to the lower two theta angle with increasing the oxygen partial pressures. XPS measurements showed that the Ni2p peak involves satellite peaks and two oxidation states of Ni, Ni2+ and Ni3+, have been existed together with the corresponding splitting in O1s spectrum. P-type conductivity of the grown NiO thin films are confirmed by the Hall measurements with concentrations on the order of 1013 holes/cm-3. Gas sensor measurements revealed minimum of 10% response to the 10 ppm H2 level. Enhanced responsivity of the gas sensor devices of NiO thin films is shown as the oxygen partial pressure increases.

A statistical approach to selecting and confirming validation targets in -omics experiments

PubMed Central

2012-01-01

Background Genomic technologies are, by their very nature, designed for hypothesis generation. In some cases, the hypotheses that are generated require that genome scientists confirm findings about specific genes or proteins. But one major advantage of high-throughput technology is that global genetic, genomic, transcriptomic, and proteomic behaviors can be observed. Manual confirmation of every statistically significant genomic result is prohibitively expensive. This has led researchers in genomics to adopt the strategy of confirming only a handful of the most statistically significant results, a small subset chosen for biological interest, or a small random subset. But there is no standard approach for selecting and quantitatively evaluating validation targets. Results Here we present a new statistical method and approach for statistically validating lists of significant results based on confirming only a small random sample. We apply our statistical method to show that the usual practice of confirming only the most statistically significant results does not statistically validate result lists. We analyze an extensively validated RNA-sequencing experiment to show that confirming a random subset can statistically validate entire lists of significant results. Finally, we analyze multiple publicly available microarray experiments to show that statistically validating random samples can both (i) provide evidence to confirm long gene lists and (ii) save thousands of dollars and hundreds of hours of labor over manual validation of each significant result. Conclusions For high-throughput -omics studies, statistical validation is a cost-effective and statistically valid approach to confirming lists of significant results. PMID:22738145

CO dissociation and CO hydrogenation on smooth and ion-bombarded Pd(1 1 1): SFG and XPS spectroscopy at mbar pressures

NASA Astrophysics Data System (ADS)

Rupprechter, G.; Kaichev, V. V.; Unterhalt, H.; Morkel, M.; Bukhtiyarov, V. I.

2004-07-01

The CO dissociation probability on transition metals is often invoked to explain the product distribution (selectivity) of catalytic CO hydrogenation. Along these lines, we have investigated CO adsorption and dissociation on smooth and ion-bombarded Pd(1 1 1) at pressures up to 1 mbar using vibrational sum frequency generation (SFG) and X-ray photoelectron spectroscopy (XPS). Under high pressure, CO adsorbate structures were observed that were identical to high-coverage structures in UHV. On ion-bombarded surfaces an additional species was detected which was attributed to CO bridge bonded to defect (low-coordinated) sites. On both surfaces, no indications of CO dissociation were found even after hours of 0.1 mbar CO exposure. However, exposing CO/H 2 mixtures to ion-bombarded Pd(1 1 1) produced carbonaceous deposits suggesting CH xO species as precursors for CO bond cleavage and that the formation of CH xO is facilitated by surface defects. The relevance of the observations for CO hydrogenation on Pd catalysts is discussed.

Wettability and XPS analyses of nickel-phosphorus surfaces after plasma treatment: An efficient approach for surface qualification in mechatronic processes

NASA Astrophysics Data System (ADS)

Vivet, L.; Joudrier, A.-L.; Bouttemy, M.; Vigneron, J.; Tan, K. L.; Morelle, J. M.; Etcheberry, A.; Chalumeau, L.

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 be

Combined far infrared RAIRS and XPS studies of TiCl 4 adsorption and reaction on Mg films

NASA Astrophysics Data System (ADS)

Pilling, M. J.; Fonseca, A. Amieiro; Cousins, M. J.; Waugh, K. C.; Surman, M.; Gardner, P.

2005-08-01

In recent years there has been an increase in interest in the study of model Ziegler-Natta catalysts used for the polymerisation of ethene and propene. Particular attention has focused on catalysts consisting of TiCl 4 on activated MgCl 2 accompanied by a co-catalyst, usually triethylaluminium (AlEt 3). As part of a wider project on the characterisation of model Ziegler-Natta catalysts we have investigated the interaction of TiCl 4 with metallic Mg films grown on a Au surface using X-ray photoelectron spectroscopy (XPS) and far infrared reflection absorption infrared spectroscopy. Somewhat surprisingly, the infrared spectra show little variation as a function of exposure to TiCl 4. A very broad asymmetric vibrational band grows in with maximum intensity at 382 cm -1. Three prominent low frequency shoulders are observed at approximately 360, 320, and 260 cm -1. For monolayer coverages of Mg the main band at 382 cm -1 is narrower, less asymmetric and accompanied by a prominent shoulder at 398 cm -1, which increases with increasing exposure to TiCl 4. TiCl 4 exposure in the presence of 5 × 10 -8 Torr of ethyl benzoate results in a change in line shape with low frequency broadening and a small shift in the frequency of the band. These spectra are discussed in the light of the possible constituent species making up the surface layer.

Determination of trace metals in TSP and PM2.5 materials collected in the Metropolitan Area of Monterrey, Mexico: A characterization study by XPS, ICP-AES and SEM-EDS

NASA Astrophysics Data System (ADS)

González, Lucy T.; Longoria Rodríguez, F. E.; Sánchez-Domínguez, M.; Cavazos, Aleyda; Leyva-Porras, C.; Silva-Vidaurri, L. G.; Askar, Karim Acuña; Kharissov, B. I.; Villarreal Chiu, J. F.; Alfaro Barbosa, J. M.

2017-11-01

The concentration levels of trace metals of toxicological importance were evaluated in the total suspended particles (TSP) and particulate matter smaller than 2.5 μm (PM2.5) collected in the Metropolitan Area of Monterrey (MAM) in Mexico. Samples were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with an energy-dispersive spectroscopy system (SEM-EDS). In addition, the data were statistically treated by the methodology of Pearson Correlation (PC) and Principal Components Analysis (PCA) to identify the possible emitting sources. Surface analysis of the particulate matter (PM) by XPS revealed that the most abundant elements were Ca, Al, Na, Zn, Cu and Mg. The deconvolution of the Ca2p, Zn2p and Cu2p signals showed that the main contributors were CaCO3, ZnO and Cu/Cu2O, respectively. The bulk analysis of the PM by ICP-AES showed Fe, Cu and Zn as the most abundant elements. Fe-rich particles presented two different morphologies: the prismatic particles were associated with a natural origin, while the spherical particles with anthropogenic sources. The Zn and Cu were predominantly observed in the sampling stations with high vehicular traffic, and the emitting sources were associated with the burning of fuels from automobiles and the wear of the tires and brakes. The highest concentration of Pb was detected in the sampling station located near the industrial zones, and its cause was associated with the ceramic and glass industries, the burning of fuel oil in power plants and the production of lead-based batteries for automobiles.

Poliomyelitis case confirmation: characteristics for use by national eradication programmes.

PubMed Central

Biellik, R. J.; Bueno, H.; Olive, J. M.; de Quadros, C.

1992-01-01

Highly sensitive case definitions were first introduced by national poliomyelitis eradication programmes to avoid missing true cases of the disease, though false-positive diagnostic errors could still occur owing to low specificity. Extensive data from all 1620 cases of acute, flaccid paralysis reported in Brazil during 1987-88 provided an opportunity to study the characteristics of confirmed poliomyelitis cases and epidemiologically to evaluate potential case definitions that maximized both sensitivity and specificity. Cases that had been confirmed by wild poliomyelitis virus isolation were compared with those that had been rejected (non-polio cases). To guarantee the consistency of clinical, epidemiological and laboratory investigations, only cases less than 10 years of age that had been investigated within 15 days of the onset and with complete laboratory specimens were included. No single practical case definition combining both high sensitivity and high specificity emerged from the study. However, the results showed that poliomyelitis endemic countries with limited resources should give priority to the investigation of cases in less than 5-year-olds, cases with prodromal fever, cases without involvement in all four limbs, cases without progression greater than 3 days after the onset, and cases occurring in areas where poliomyelitis had recently been confirmed. In countries without laboratory resources, cases of acute, flaccid paralysis with initial involvement in one or both lower limbs and residual neurological sequelae at 60 days should be confirmed. Countries that are close to eradication may selectively reject any cases lacking laboratory confirmation, despite adequate specimen collection, if they do not have initial involvement in one or both lower limbs and residual neurological sequelae at 60 days. PMID:1314710

Elucidating the resistance to failure under tribological tests of various boron-based films by XPS and ToF-SIMS

NASA Astrophysics Data System (ADS)

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.

Confirmation of elevated arsenic levels in groundwater of Myanmar

PubMed Central

van Geen, Alexander; Win, Kyi Htut; Zaw, Than; Naing, Win; Mey, Jacob L.; Mailloux, Brian

2014-01-01

Millions of villagers across South and Southeast Asia are exposed to toxic levels of arsenic (As) by drinking well water. In order to confirm field-kit results that Myanmar is also affected, a total of 55 wells were tested in the field in January 2013 and sampled for laboratory analysis across seven villages spanning a range of As contamination in the lower Ayeyarwady basin. Elevated concentrations of As (50–630 μg/L) were measured in wells up to 60 m deep and associated with high levels of Fe (up to 21 mg/L) and low concentrations of SO4 (<0.05 mg/L). Concentrations of As <10 μg/L were measured in some shallow (<30 m) grey sands and in both shallow and deep orange sands. These results indicate that the main mechanism of As release to groundwater in Myanmar is the reductive dissolution of Fe oxyhydroxides, as in the neighboring Bengal, Mekong, and Red River basins. Concentrations of As in groundwater of Myanmar are therefore unlikely to change rapidly over time and switching to existing low-As wells is a viable way of reducing exposure in the short term. However, only 17 of the 55 well owners interviewed correctly recalled the status of their well despite extensive testing in the region. A renewed effort is thus needed to test existing wells and new wells that continue to be installed and to communicate the health risks of exposure to As for infants, children, and adults. PMID:24530581

Electronic structure of the indium tin oxide/nanocrystalline anatase (TiO2)/ruthenium-dye interfaces in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Lyon, J. E.; Rayan, M. K.; Beerbom, M. M.; Schlaf, R.

2008-10-01

The electronic structure of two interfaces commonly found in dye-sensitized photovoltaic cells based on nanocrystalline anatase TiO2 ("Grätzel cells") was investigated using photoemission spectroscopy (PES). X-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) measurements were carried out on the indium tin oxide (ITO)/TiO2 and the TiO2/cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)bis-tetrabutylammonium dye ("N719" or "Ruthenium 535-bisTBA") interfaces. Both contacts were investigated using a multistep deposition procedure where the entire structure was prepared in vacuum using electrospray deposition. In between deposition steps the surface was characterized with XPS and UPS resulting in a series of spectra, allowing the determination of the orbital and band lineup at the interfaces. The results of these efforts confirm previous PES measurements on TiO2/dye contacts prepared under ambient conditions, suggesting that ambient contamination might not have significant influence on the electronic structure at the dye/TiO2 interface. The results also demonstrate that there may be a significant barrier for electron injection at the sputtered ITO/TiO2 interface and that this interface should be viewed as a semiconductor heterojunction rather than as metal-semiconductor (Schottky) contact.

Amide group anchored glucose oxidase based anodic catalysts for high performance enzymatic biofuel cell

NASA Astrophysics Data System (ADS)

Chung, Yongjin; Ahn, Yeonjoo; Kim, Do-Heyoung; Kwon, Yongchai

2017-01-01

A new enzyme catalyst is formed by fabricating gold nano particle (GNP)-glucose oxidase (GOx) clusters that are then attached to polyethyleneimine (PEI) and carbon nanotube (CNT) with cross-linkable terephthalaldehyde (TPA) (TPA/[CNT/PEI/GOx-GNP]). Especially, amide bonds belonging to TPA play an anchor role for incorporating rigid bonding among GNP, GOx and CNT/PEI, while middle size GNP is well bonded with thiol group of GOx to form strong GNP-GOx cluster. Those bonds are identified by chemical and electrochemical characterizations like XPS and cyclic voltammogram. The anchording effect of amide bonds induces fast electron transfer and strong chemical bonding, resulting in enhancements in (i) catalytic activity, (ii) amount of immobilized GOx and (ii) performance of enzymatic biofuel cell (EBC) including the catalyst. Regarding the catalytic activity, the TPA/[CNT/PEI/GOx-GNP] produces high electron transfer rate constant (6 s-1), high glucose sensitivity (68 μA mM-1 cm-2), high maximum current density (113 μA cm-2), low charge transfer resistance (17.0 Ω cm2) and long-lasting durability while its chemical structure is characterized by XPS confirming large portion of amide bond. In EBC measurement, it has high maximum power density (0.94 mW cm-2) compatible with catalytic acitivity measurements.

Zeta potential orientation dependence of sapphire substrates.

PubMed

Kershner, Ryan J; Bullard, Joseph W; Cima, Michael J

2004-05-11

The zeta potential of planar sapphire substrates for three different crystallographic orientations was measured by a streaming potential technique in the presence of KCl and (CH3)4NCl electrolytes. The streaming potential was measured for large single crystalline C-plane (0001), A-plane (1120), and R-plane (1102) wafers over a full pH range at three or more ionic strengths ranging from 1 to 100 mM. The roughness of the epi-polished wafers was verified using atomic force microscopy to be on the order of atomic scale, and X-ray photoelectron spectroscopy (XPS) was used to ensure that the samples were free of silica and other contaminants. The results reveal a shift in the isoelectric point (iep) of the three samples by as much as two pH units, with the R-plane surface exhibiting the most acidic behavior and the C-plane samples having the highest iep. The iep at all ionic strengths was tightly centered around a single pH for each wafer. These values of iep are substantially different from the range of pH 8-10 consistently reported in the literature for alpha-Al2O3 particles. Particle zeta potential measurements were performed on a model powder using phase analysis light scattering, and the iep was confirmed to occur at pH 8. Modified Auger parameters (MAP) were calculated from XPS spectra of a monolayer of iridium metal deposited on the sapphire by electron beam deposition. A shift in MAP consistent with the observed differences in iep of the surfaces confirms the effect of surface structure on the transfer of charge between the Ir and sapphire, hence accounting for the changes in acidity as a function of crystallographic orientation.

Confidential donation confirmation as an alternative to confidential unit exclusion: 15 months experience of the HEMOMINAS foundation.

PubMed

Loureiro, Flávia Cristine Martineli; Oliveira, Cláudia Di Lorenzo; Proietti, Anna Bárbara F Carneiro; Proietti, Fernando Augusto

2011-01-01

Confidential unit exclusion remains a controversial strategy to reduce the residual risk of transfusion-transmitted infections. This study aimed to analyze confidential unit exclusion from its development in a large institution in light of confidential donation confirmation. Data of individuals who donated from October 1, 2008 to December 31, 2009 were analyzed in a case-control study. The serological results and sociodemographic characteristics of donors who did not confirm their donations were compared to those who did. Variables with p-values < 0.20 in univariate analysis were included in a logistic multivariate analysis. In the univariate analysis there was a statically significant association between positive serological results and response to confidential donation confirmation of "No". Donation type, (firsttime or return donor - OR 1.69, CI 1.37-2.09), gender (OR 1.66, CI 1.35-2.04), education level (OR 2.82, CI 2.30-3.47) and ethnic background (OR 0.67, CI 0.55-0.82) were included in the final logistic regression model. In all logistic regression models analyzed, the serological suitability and confidential donation confirmation were not found to be statistically associated. The adoption of new measures of clinical classification such as audiovisual touch-screen computer-assisted self-administered interviews might be more effective than confidential unit exclusion in the identification of donor risk behavior. The requirement that transfusion services continue to use confidential unit exclusion needs to be debated in countries where more specific and sensitive clinical and serological screening methods are available. Our findings suggest that there are not enough benefits to justify continued use of confidential donation confirmation in the analyzed institution.

Confidential donation confirmation as an alternative to confidential unit exclusion: 15 months experience of the HEMOMINAS foundation

PubMed Central

Loureiro, Flávia Cristine Martineli; Oliveira, Cláudia Di Lorenzo; Proietti, Anna Bárbara F. Carneiro; Proietti, Fernando Augusto

2011-01-01

Background Confidential unit exclusion remains a controversial strategy to reduce the residual risk of transfusion-transmitted infections. Objective This study aimed to analyze confidential unit exclusion from its development in a large institution in light of confidential donation confirmation. Methods Data of individuals who donated from October 1, 2008 to December 31, 2009 were analyzed in a case-control study. The serological results and sociodemographic characteristics of donors who did not confirm their donations were compared to those who did. Variables with p-values < 0.20 in univariate analysis were included in a logistic multivariate analysis. Results In the univariate analysis there was a statically significant association between positive serological results and response to confidential donation confirmation of "No". Donation type, (firsttime or return donor - OR 1.69, CI 1.37-2.09), gender (OR 1.66, CI 1.35-2.04), education level (OR 2.82, CI 2.30-3.47) and ethnic background (OR 0.67, CI 0.55-0.82) were included in the final logistic regression model. In all logistic regression models analyzed, the serological suitability and confidential donation confirmation were not found to be statistically associated. The adoption of new measures of clinical classification such as audiovisual touch-screen computer-assisted self-administered interviews might be more effective than confidential unit exclusion in the identification of donor risk behavior. The requirement that transfusion services continue to use confidential unit exclusion needs to be debated in countries where more specific and sensitive clinical and serological screening methods are available. Conclusion Our findings suggest that there are not enough benefits to justify continued use of confidential donation confirmation in the analyzed institution. PMID:23049316

The First Confirmed Videorecordings of Lunar Meteor Impacts

NASA Technical Reports Server (NTRS)

Dunham, D. W.; Cudnik, B.; Palmer, D. M.; Sada, P. V.; Melosh, J.; Beech, M.; Pellerin, L.; Asher, D.; Frankenberger R.; Venable R.

2000-01-01

North American observers recorded at least six meteors striking the Moon's surface during the Leonid meteor shower on 1999 Nov. 18. Each meteor produced a flash that was recorded from at least two separate locations, marking the first confirmed lunar meteor impacts.

77 FR 53769 - Receipts-Based, Small Business Size Standard; Confirmation of Effective Date

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-04

...-Based, Small Business Size Standard; Confirmation of Effective Date AGENCY: Nuclear Regulatory Commission. ACTION: Direct final rule; confirmation of effective date. SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is confirming the effective date of August 22, 2012, for the direct final rule that appeared...

[Epidemiological investigation on confirmed cases of schistosomiasis in Hubei Province].

PubMed

Yan-Yan, Chen; Shun-Xiang, Cai; Guo, Li; Ying, Xiao; Xiao-Wei, Shan; Juan, Zhang; Jian-Bing, Liu

2016-05-10

To grasp the distribution and epidemiology of confirmed cases of schistosomiasis in Hubei Province, so as to provide the evidence for promoting the prevention and control work. The confirmed cases of schistosomiasis in Hubei Province from 2010 to 2014 were epidemiologically investigated, and the prevalence characteristics and main influencing factors were analyzed. A total of 10 102 confirmed cases from 2010 to 2014 were surveyed. There were 1 062 local infected patients, accounting for 10.51% and including 354 repeated infections and 17 newly infected. There were 290 foreigninfected patients, accounting for 2.87%, with 206 repeated infection cases and 84 newly infected. There were 8 750 historical patients, including 2 229 patients who leaked the former schistosomiasis investigations, accounting for 22.06%; 570 patients missed treatment, accounting for 5.64%; 3 640 patients were treated with non-standard therapy, accounting for 36.03%; 2 311 patients were treated with poor medication efficacy, accounting for 22.88%. The multivariate non-conditional Logistic regression, targeting at confirmed cases in 2014, showed that, for the leaking investigations, the potential risk factors included the age, educational level, and latrine renovation ( b ＞0, OR ＞1), the protective factors were the times of previous treatment, cattle feeding in villager team, and Oncomelania hupensis snails in surroundings ( b ＜0, OR ＜1); for the treatment-missing, the age, educational level, snails in the surroundings of residence were risk factors ( b ＜0, OR ＜1); for the substandard treatment, the risk factors included the occupation and snails in the surroundings of residence ( b ＞0, OR ＞1), and the educational level and snails in the own field were protective factors ( b ＜0, OR ＜1). The epidemiological investigation on the confirmed cases of schistosomiasis could grasp the epidemic factors so as to improve the management and carry out the scientific control.

The relationship between the surface composition and electrical properties of corrosion films formed on carbon steel in alkaline sour medium: an XPS and EIS study.

PubMed

Galicia, Policarpo; Batina, Nikola; González, Ignacio

2006-07-27

This work studies the evolution of 1018 carbon steel surfaces during 3-15 day immersion in alkaline sour medium 0.1 M (NH4)2S and 10 ppm CN(-) as (NaCN). During this period of time, surfaces were jointly characterized by electrochemical techniques in situ (electrochemical impedance spectroscopy, EIS) and spectroscopic techniques ex situ (X-ray photoelectron spectroscopy, XPS). The results obtained by these techniques allowed for a description of electrical and chemical properties of the films of corrosion products formed at the 1018 steel surface. There is an interconversion cycle of chemical species that form films of corrosion products whose conversion reactions favor two different types of diffusions inside the films: a chemical diffusion of iron cations and a typical diffusion of atomic hydrogen. These phenomena jointly control the passivity of the interface attacked by the corrosive medium.

The origin of the residual conductivity of GaN films on ferroelectric materials

NASA Astrophysics Data System (ADS)

Lee, Kyoung-Keun; Cai, Zhuhua; Ziemer, Katherine; Doolittle, William Alan

2009-08-01

In this paper, the origin of the conductivity of GaN films grown on ferroelectric materials was investigated using XPS, AES, and XRD analysis tools. Depth profiles confirmed the existence of impurities in the GaN film originating from the substrates. Bonding energy analysis from XPS and AES verified that oxygen impurities from the substrates were the dominant origin of the conductivity of the GaN film. Furthermore, Ga-rich GaN films have a greater chance of enhancing diffusion of lithium oxide from the substrates, resulting in more substrate phase separation and a wider inter-mixed region confirmed by XRD. Therefore, the direct GaN film growth on ferroelectric materials causes impurity diffusion from the substrates, resulting in highly conductive GaN films. Future work needs to develop non-conductive buffer layers for impurity suppression in order to obtain highly resistive GaN films.

[Confirming Indicators of Qualitative Results by Chromatography-mass Spectrometry in Biological Samples].

PubMed

Liu, S D; Zhang, D M; Zhang, W; Zhang, W F

2017-04-01

Because of the exist of complex matrix, the confirming indicators of qualitative results for toxic substances in biological samples by chromatography-mass spectrometry are different from that in non-biological samples. Even in biological samples, the confirming indicators are different in various application areas. This paper reviews the similarities and differences of confirming indicators for the analyte in biological samples by chromatography-mass spectrometry in the field of forensic toxicological analysis and other application areas. These confirming indicators include retention time （RT）, relative retention time （RRT）, signal to noise （S/N）, characteristic ions, relative abundance of characteristic ions, parent ion-daughter ion pair and abundance ratio of ion pair, etc. Copyright© by the Editorial Department of Journal of Forensic Medicine.

Conduction band offset at GeO{sub 2}/Ge interface determined by internal photoemission and charge-corrected x-ray photoelectron spectroscopies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, W. F.; Nishimula, T.; Nagashio, K.

2013-03-11

We report a consistent conduction band offset (CBO) at a GeO{sub 2}/Ge interface determined by internal photoemission spectroscopy (IPE) and charge-corrected X-ray photoelectron spectroscopy (XPS). IPE results showed that the CBO value was larger than 1.5 eV irrespective of metal electrode and substrate type variance, while an accurate determination of valence band offset (VBO) by XPS requires a careful correction of differential charging phenomena. The VBO value was determined to be 3.60 {+-} 0.2 eV by XPS after charge correction, thus yielding a CBO (1.60 {+-} 0.2 eV) in excellent agreement with the IPE results. Such a large CBO (>1.5more » eV) confirmed here is promising in terms of using GeO{sub 2} as a potential passivation layer for future Ge-based scaled CMOS devices.« less

Teaching Scientific Method: The Logic of Confirmation and Falsification.

ERIC Educational Resources Information Center

Garrison, James W.; Bentley, Michael L.

1990-01-01

Presents important principles and issues related to postpositivism including logic of confirmation and logic of falsification. Discusses possible applications in science education. Lists 23 references. (YP)

On the determinants of the conjunction fallacy: probability versus inductive confirmation.

PubMed

Tentori, Katya; Crupi, Vincenzo; Russo, Selena

2013-02-01

Major recent interpretations of the conjunction fallacy postulate that people assess the probability of a conjunction according to (non-normative) averaging rules as applied to the constituents' probabilities or represent the conjunction fallacy as an effect of random error in the judgment process. In the present contribution, we contrast such accounts with a different reading of the phenomenon based on the notion of inductive confirmation as defined by contemporary Bayesian theorists. Averaging rule hypotheses along with the random error model and many other existing proposals are shown to all imply that conjunction fallacy rates would rise as the perceived probability of the added conjunct does. By contrast, our account predicts that the conjunction fallacy depends on the added conjunct being perceived as inductively confirmed. Four studies are reported in which the judged probability versus confirmation of the added conjunct have been systematically manipulated and dissociated. The results consistently favor a confirmation-theoretic account of the conjunction fallacy against competing views. Our proposal is also discussed in connection with related issues in the study of human inductive reasoning. 2013 APA, all rights reserved

Histopathology confirms white-nose syndrome in bats in Europe

USGS Publications Warehouse

Pikula, J.; Bandouchova, H.; Novotny, L.; Meteyer, C.U.; Zukal, J.; Irwin, N.R.; Zima, J.; Martinkova, N.

2012-01-01

White-nose syndrome, associated with the fungal skin infection geomycosis, caused regional population collapse in bats in North America. Our results, based on histopathology, show the presence of white-nose syndrome in Europe. Dermatohistopathology on two bats (Myotis myotis) found dead in March 2010 with geomycosis in the Czech Republic had characteristics resembling Geomyces destructans infection in bats confirmed with white-nose syndrome in US hibernacula. In addition, a live M. myotis, biopsied for histopathology during hibernation in April 2011, had typical fungal infection with cupping erosion and invasion of muzzle skin diagnostic for white-nose syndrome and conidiospores identical to G. destructans that were genetically confirmed as G. destructans. ?? Wildlife Disease Association 2012.

An interest in fame: confirming the measurement and empirical conceptualization of fame interest.

PubMed

Maltby, John

2010-08-01

The following paper introduces and develops the conceptualization of Fame Interest. Study 1 (N=1,978), through the use of factor analysis techniques, introduces the Fame Interest Scale which comprises six dimensions of Fame Interest (intensity, vulnerability, celebrity life-style, drive, perceived suitability, and altruistic) with evidence for the reliability and validity of the scale. Study 2 (N=376) examined the relationship between an interest in fame and measures of the five-factor model of personality, narcissism, self-esteem, curiosity, attachment style and perceived family, and peer and media influence. From this second study four findings emerge; (1) Fame Interest typified by a perceived suitability and intensity for a celebrity life-style was associated with perceived family, peer and media influence, (2) Fame Interest that arises from a vulnerability is a reflection of neuroticism, low self-esteem, and problematic attachments, (3) Fame Interest for altruistic reasons is associated with agreeableness, and (4) Fame Interest that reflects an overall drive is associated with conscientiousness.

A near ambient pressure XPS study of subnanometer silver clusters on Al 2O 3 and TiO 2 ultrathin film supports

DOE PAGES

Mao, Bao -Hua; Chang, Rui; Shi, Lei; ...

2014-10-29

Here, 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, O 2 and CO) at different temperatures. Compared to bulk silver, the binding energies of silver clusters are about 0.55 eV higher on TiO 2 and 0.95 eV higher on Al 2O 3 due to the final state effect and the interaction with supports. No clear size effect of the silver XPS peak ismore » 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.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrokhzadeh, Abdolkarim; Modarresi-Alam, Ali Reza, E-mail: modaresi@chem.usb.ac.ir

Poly [(±)-2-(sec-butyl) aniline]/silica-supported perchloric acid composites were synthesized by combination of poly[(±)-2-sec-butylaniline] base (PSBA) and the silica-supported perchloric acid (SSPA) as dopant solid acid in solid-state. The X-ray photoelectron spectroscopy (XPS) and CHNS results confirm nigraniline oxidation state and complete doping for composites (about 75%) and non-complete for the PSBA·HCl salt (about 49%). The conductivity of samples was (≈0.07 S/cm) in agreement with the percent of doping obtained of the XPS analysis. Also, contact resistance was determined by circular-TLM measurement. The morphology of samples by the scanning electron microscopy (SEM) and their coating were investigated by XPS, SEM-map and energy-dispersivemore » X-ray spectroscopy (EDX). The key benefits of this work are the preparation of conductive chiral composite with the delocalized polaron structure under green chemistry and solid-state condition, the improvement of the processability by inclusion of the 2-sec-butyl group and the use of dopant solid acid (SSPA) as dopant. - Highlights: • The solid-state synthesis of the novel chiral composites of poly[(±)-2-(sec-butyl)aniline] (PSBA) and silica-supported perchloric acid (SSPA). • It takes 120 h for complete deprotonation of PSBA.HCl salt. • Use of SSPA as dopant solid acid for the first time to attain the complete doping of PSBA. • The coating of silica surface with PSBA.« less

Autopsy-confirmed Alzheimer's disease versus clinically diagnosed Alzheimer's disease in the Cache County Study on Memory and Aging: a comparison of quantitative MRI and neuropsychological findings.

PubMed

Fearing, Michael A; Bigler, Erin D; Norton, Maria; Tschanz, Jo Ann; Hulette, Christine; Leslie, Carol; Welsh-Bohmer, Kathleen

2007-07-01

Atrophy of specific, regional, and generalized brain structures occurs as a result of the Alzheimer's disease (AD) process. Comparing AD patients with histopathological confirmation of the disease at autopsy to those without autopsy but who were clinically diagnosed using the same antemortem criteria will provide further evidence of the utility and accuracy of neuropsychological assessments at the time of diagnosis, as well as the efficacy of quantitative magnetic resonance imaging (qMRI) in demonstrating gross neuropathological changes associated with the disease. The Cache County Study of Aging provides a unique opportunity to determine how closely AD subjects with only the clinical diagnosis match similarly diagnosed AD subjects but with postmortem confirmation of the disease. qMRI volumes of various brain structures, as well as neuropsychological outcome measures from an expanded battery, were obtained in 31 autopsy-confirmed AD subjects and 45 clinically diagnosed AD subjects. Of the various qMRI variables examined, only total temporal lobe volume was different, where those with postmortem confirmation had reduced volume. No significant differences between the two groups were found with any of the neuropsychological outcome measures. These findings confirm the similarity in neuroimaging and neuropsychological assessment findings between those with just the clinical diagnosis of AD and those with an autopsy-confirmed diagnosis in the moderate-to-severe stage of the disease at the time of diagnosis.

Clustering on very small scales from a large, complete sample of confirmed quasar pairs

NASA Astrophysics Data System (ADS)

Eftekharzadeh, Sarah; Myers, Adam D.; Djorgovski, Stanislav G.; Graham, Matthew J.; Hennawi, Joseph F.; Mahabal, Ashish A.; Richards, Gordon T.

2016-06-01

We present by far the largest sample of spectroscopically confirmed binaryquasars with proper transverse separations of 17.0 ≤ Rprop ≤ 36.6 h-1 kpc. Our sample, whichis an order-of-magnitude larger than previous samples, is selected from Sloan Digital Sky Survey (SDSS) imaging over an area corresponding to the SDSS 6th data release (DR6). Our quasars are targeted using a Kernel Density Estimation technique (KDE), and confirmed using long-slit spectroscopy on a range of facilities.Our most complete sub-sample of 44 binary quasars with g<20.85, extends across angular scales of 2.9" < Δθ < 6.3", and is targeted from a parent sample that would be equivalent to a full spectroscopic survey of nearly 300,000 quasars.We determine the projected correlation function of quasars (\\bar Wp) over proper transverse scales of 17.0 ≤ Rprop ≤ 36.6 h-1 kpc, and also in 4 bins of scale within this complete range.To investigate the redshift evolution of quasar clustering on small scales, we make the first self-consistent measurement of the projected quasar correlation function in 4 bins of redshift over 0.4 ≤ z ≤ 2.3.

A new virus of soybean confirmed in Wisconsin

USDA-ARS?s Scientific Manuscript database

This week our laboratory confirmed the presence of Soybean vein necrosis-associated virus (SVNaV) in soybeans sampled in Wisconsin. Samples were taken at several times during September and processed in our laboratory. Symptoms of the disease caused by the virus include yellowing (chlorosis) of the ...

Correlation of Cellular Immune Responses with Protection against Culture-Confirmed Influenza Virus in Young Children▿

PubMed Central

Forrest, Bruce D.; Pride, Michael W.; Dunning, Andrew J.; Capeding, Maria Rosario Z.; Chotpitayasunondh, Tawee; Tam, John S.; Rappaport, Ruth; Eldridge, John H.; Gruber, William C.

2008-01-01

The highly sensitive gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISPOT) assay permits the investigation of the role of cell-mediated immunity (CMI) in the protection of young children against influenza. Preliminary studies of young children confirmed that the IFN-γ ELISPOT assay was a more sensitive measure of influenza memory immune responses than serum antibody and that among seronegative children aged 6 to <36 months, an intranasal dose of 107 fluorescent focus units (FFU) of a live attenuated influenza virus vaccine (CAIV-T) elicited substantial CMI responses. A commercial inactivated influenza virus vaccine elicited CMI responses only in children with some previous exposure to related influenza viruses as determined by detectable antibody levels prevaccination. The role of CMI in actual protection against community-acquired, culture-confirmed clinical influenza by CAIV-T was investigated in a large randomized, double-blind, placebo-controlled dose-ranging efficacy trial with 2,172 children aged 6 to <36 months in the Philippines and Thailand. The estimated protection curve indicated that the majority of infants and young children with ≥100 spot-forming cells/106 peripheral blood mononuclear cells were protected against clinical influenza, establishing a possible target level of CMI for future influenza vaccine development. The ELISPOT assay for IFN-γ is a sensitive and reproducible measure of CMI and memory immune responses and contributes to establishing requirements for the future development of vaccines against influenza, especially those used for children. PMID:18448618

Confirming the Lanchestrian linear-logarithmic model of attrition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartley, D.S. III.

1990-12-01

This paper is the fourth in a series of reports on the breakthrough research in historical validation of attrition in conflict. Significant defense policy decisions, including weapons acquisition and arms reduction, are based in part on models of conflict. Most of these models are driven by their attrition algorithms, usually forms of the Lanchester square and linear laws. None of these algorithms have been validated. The results of this paper confirm the results of earlier papers, using a large database of historical results. The homogeneous linear-logarithmic Lanchestrian attrition model is validated to the extent possible with current initial and finalmore » force size data and is consistent with the Iwo Jima data. A particular differential linear-logarithmic model is described that fits the data very well. A version of Helmbold's victory predicting parameter is also confirmed, with an associated probability function. 37 refs., 73 figs., 68 tabs.« less

Students' Perceived Understanding: An Alternative Measure and Its Associations with Perceived Teacher Confirmation, Verbal Aggressiveness, and Credibility

ERIC Educational Resources Information Center

Schrodt, Paul; Finn, Amber N.

2011-01-01

Given recent questions regarding the construct validity of Cahn and Shulman's Feelings of Understanding/Misunderstanding scale, two studies were conducted to develop a low-inference, behavioral measure of students' perceived understanding in the college classroom. In Study One (N = 265), a pilot inventory was developed to measure students'…

Histopathologic criteria to confirm white-nose syndrome in bats

USGS Publications Warehouse

Meteyer, Carol U.; Buckles, Elizabeth L.; Blehert, David S.; Hicks, Alan C.; Green, David E.; Shearn-Bochsler, Valerie I.; Thomas, Nancy J.; Gargas, Andrea; Behr, Melissa

2009-01-01

White-nose syndrome (WNS) is a cutaneous fungal disease of hibernating bats associated with a novel Geomyces sp. fungus. Currently, confirmation of WNS requires histopathologic examination. Invasion of living tissue distinguishes this fungal infection from those caused by conventional transmissible dermatophytes. Although fungal hyphae penetrate the connective tissue of glabrous skin and muzzle, there is typically no cellular inflammatory response in hibernating bats. Preferred tissue samples to diagnose this fungal infection are rostral muzzle with nose and wing membrane fixed in 10% neutral buffered formalin. To optimize detection, the muzzle is trimmed longitudinally, the wing membrane is rolled, and multiple cross-sections are embedded to increase the surface area examined. Periodic acid-Schiff stain is essential to discriminate the nonpigmented fungal hyphae and conidia. Fungal hyphae form cup-like epidermal erosions and ulcers in the wing membrane and pinna with involvement of underlying connective tissue. In addition, fungal hyphae are present in hair follicles and in sebaceous and apocrine glands of the muzzle with invasion of tissue surrounding adnexa. Fungal hyphae in tissues are branching and septate, but the diameter and shape of the hyphae may vary from parallel walls measuring 2 ??m in diameter to irregular walls measuring 3-5 ??m in diameter. When present on short aerial hyphae, curved conidia are approximately 2.5 ??m wide and 7.5 ??m in curved length. Conidia have a more deeply basophilic center, and one or both ends are usually blunt. Although WNS is a disease of hibernating bats, severe wing damage due to fungal hyphae may be seen in bats that have recently emerged from hibernation. These recently emerged bats also have a robust suppurative inflammatory response.

Histopathologic criteria to confirm white-nose syndrome in bats.

PubMed

Meteyer, Carol Uphoff; Buckles, Elizabeth L; Blehert, David S; Hicks, Alan C; Green, D Earl; Shearn-Bochsler, Valerie; Thomas, Nancy J; Gargas, Andrea; Behr, Melissa J

2009-07-01

White-nose syndrome (WNS) is a cutaneous fungal disease of hibernating bats associated with a novel Geomyces sp. fungus. Currently, confirmation of WNS requires histopathologic examination. Invasion of living tissue distinguishes this fungal infection from those caused by conventional transmissible dermatophytes. Although fungal hyphae penetrate the connective tissue of glabrous skin and muzzle, there is typically no cellular inflammatory response in hibernating bats. Preferred tissue samples to diagnose this fungal infection are rostral muzzle with nose and wing membrane fixed in 10% neutral buffered formalin. To optimize detection, the muzzle is trimmed longitudinally, the wing membrane is rolled, and multiple cross-sections are embedded to increase the surface area examined. Periodic acid-Schiff stain is essential to discriminate the nonpigmented fungal hyphae and conidia. Fungal hyphae form cup-like epidermal erosions and ulcers in the wing membrane and pinna with involvement of underlying connective tissue. In addition, fungal hyphae are present in hair follicles and in sebaceous and apocrine glands of the muzzle with invasion of tissue surrounding adnexa. Fungal hyphae in tissues are branching and septate, but the diameter and shape of the hyphae may vary from parallel walls measuring 2 microm in diameter to irregular walls measuring 3-5 microm in diameter. When present on short aerial hyphae, curved conidia are approximately 2.5 microm wide and 7.5 microm in curved length. Conidia have a more deeply basophilic center, and one or both ends are usually blunt. Although WNS is a disease of hibernating bats, severe wing damage due to fungal hyphae may be seen in bats that have recently emerged from hibernation. These recently emerged bats also have a robust suppurative inflammatory response.

Creatinine concentrations of accumulated intrauterine fluid to confirm the clinical diagnosis of urometra in mares.

PubMed

Schnobrich, M R; Gordon, D L; Scoggin, C F; Bradecamp, E A; Canisso, I F

2017-03-25

Urine pooling, as a persistent condition, is a cause of infertility in mares due to endometrial inflammation and sperm toxicity. Identification of urometra can be challenging in mares presenting with the condition intermittently, or when urine flows into the uterus but is undetectable in the vagina. Currently, there are no reported objective methods to confirm the clinical diagnosis of urine contamination in intrauterine-fluid accumulations. Since creatinine is present in high concentrations in urine and does not diffuse across cell membranes, creatinine concentration should be increased in mares with urometra, but negligible in normal and mares with intrauterine fluid accumulation (non-urometra cases). To test this hypothesis, creatinine concentrations of intrauterine fluid were measured in mares with a clinical diagnosis of urine accumulation (n=9) or intrauterine fluid containing no urine (n=10). Results showed that creatinine concentrations (mg/dl) were significantly higher in mares that had a clinical diagnosis of urometra (42.8±12.6, range 4.1-109.2) compared with those that did not (0.38±0.1, range 0-0.9). Also, two mares after urethral extension surgery demonstrated a remarkable reduction in creatinine concentrations. This study highlights an undocumented approach to confirm a clinical diagnosis of urometra in mares; the authors anticipate that testing for creatinine in the uterine fluid of mares may become a standard tool for identifying urometra in mares and confirming the success of urogenital surgeries. British Veterinary Association.

Bridenstine Appears Before Senate During Confirmation Hearing

NASA Image and Video Library

2017-11-01

On Nov. 1, Rep. Jim Bridenstine, the president’s nominee to be the next administrator of NASA, appeared before the Senate Committee on Commerce, Science, and Transportation. If confirmed, he would become NASA’s 13th Administrator. Bridenstine, a pilot in the U.S. Navy Reserve and former executive director of the Tulsa Air and Space Museum and Planetarium, was elected to the U.S. Congress in 2012 to represent Oklahoma’s First Congressional District.

Surface XPS characterization of NiTi shape memory alloy after advanced oxidation processes in UV/H 2O 2 photocatalytic system

NASA Astrophysics Data System (ADS)

Wang, R. M.; Chu, C. L.; Hu, T.; Dong, Y. S.; Guo, C.; Sheng, X. B.; Lin, P. H.; Chung, C. Y.; Chu, P. K.

2007-08-01

Surface structure of NiTi shape memory alloy (SMA) was modified by advanced oxidation processes (AOP) in an ultraviolet (UV)/H 2O 2 photocatalytic system, and then systematically characterized with x-ray photoelectron spectroscopy (XPS). It is found that the AOP in UV/H 2O 2 photocatalytic system leads to formation of titanium oxides film on NiTi substrate. Depth profiles of O, Ni and Ti show such a film possesses a graded interface structure to NiTi substrate and there is no intermediate Ni-rich layer like that produced in conventional high temperature oxidation. Except TiO 2 phase, some titanium suboxides (TiO, Ti 2O 3) may also exist in the titanium oxides film. Oxygen mainly presents in metal oxides and some chemisorbed water and OH - are found in titanium oxides film. Ni nearly reaches zero on the upper surface and relatively depleted in the whole titanium oxides film. The work indicates the AOP in UV/H 2O 2 photocatalytic system is a promising way to favor the widespread application of biomedical NiTi SMA by improving its biocompatibility.

Surface study of graphene ink for fine solid lines printed on BOPP Substrate in micro-flexographic printing using XPS analysis technique

NASA Astrophysics Data System (ADS)

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.

Relationship Between the Expansion Speed and Radial Speed of CMEs Confirmed Using Quadrature Observations from SOHO and STEREO

NASA Technical Reports Server (NTRS)

Gopalswamy, Nat; Makela, Pertti; Yashiro, Seiji

2011-01-01

It is difficult to measure the true speed of Earth-directed CMEs from a coronagraph along the Sun-Earth line because of the occulting disk. However, the expansion speed (the speed with which the CME appears to spread in the sky plane) can be measured by such coronagraph. In order to convert the expansion speed to radial speed (which is important for space weather applications) one can use empirical relationship between the two that assumes an average width for all CMEs. If we have the width information from quadrature observations, we can confirm the relationship between expansion and radial speeds derived by Gopalswamy et al. (2009, CEAB, 33, 115,2009). The STEREO spacecraft were in quadrature with SOHO (STEREO-A ahead of Earth by 87 and STEREO-B 94 behind Earth) on 2011 February 15, when a fast Earth-directed CME occurred. The CME was observed as a halo by the Large-Angle and Spectrometric Coronagraph (LASCO) on board SOHO. The sky-plane speed was measured by SOHO/LASCO as the expansion speed, while the radial speed was measured by STEREO-A and STEREO-B. In addition, STEREO-A and STEREO-B images measured the width of the CME, which is unknown from Earth view. From the SOHO and STEREO measurements, we confirm the relationship between the expansion speed (Vexp ) and radial speed (Vrad ) derived previously from geometrical considerations (Gopalswamy et al. 2009): Vrad = 1/2 (1 + cot w) Vexp, where w is the half width of the CME. STEREO-B images of the CME, we found that CME had a full width of 75 degrees, so w = 37.5 degrees. This gives the relation as Vrad = 1.15 Vexp. From LASCO observations, we measured Vexp = 897 km/s, so we get the radial speed as 1033 km/s. Direct measurement of radial speed from STEREO gives 945 km/s (STEREO-A) and 1057 km/s (STEREO-B). These numbers are different only by 2.3% and 8.5% (for STEREO-A and STEREO-B, respectively) from the computed value.

Space Weathering of Silicates Simulated by Successive Laser Irradiation: In Situ Reflectance Measurements of Fo90, Fo99+, and Sio2

NASA Technical Reports Server (NTRS)

Loeffler, M. J.; Dukes, C. A.; Christoffersen, R.; Baragiola, R. A.

2016-01-01

Pulsed-laser irradiation causes the visible-near-infrared spectral slope of olivine (Fo90 and Fo99+) and SiO2 to increase (redden), while the olivine samples darken and the SiO2 samples brighten slightly. XPS analysis shows that irradiation of Fo90 produces metallic Fe. Analytical SEM and TEM measurements confirm that reddening in the Fo90 olivine samples correlates with the production of nanophase metallic Fe (npFe0) grains, 2050 nm in size. The reddening observed in the SiO2 sample is consistent with the formation of SiO or other SiOx species that absorb in the visible. The weak spectral brightening induced by laser irradiation of SiO2 is consistent with a change in surface topography of the sample. The darkening observed in the olivine samples is likely caused by the formation of larger npFe0 particles, such as the 100400 nm diameter npFe0 identified during our TEM analysis of Fo90 samples. The Fo90 reflectance spectra are qualitatively similar to those in previous experiments suggesting that in all cases formation of npFe0 is causing the spectral alteration. Finally, we find that the accumulation of successive laserpulses cause continued sample darkening in the Vis-NIR, which suggests that repeated surface impacts are an efficient way to darken airless body surfaces.

18 CFR 300.21 - Final confirmation and approval.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Final confirmation and approval. 300.21 Section 300.21 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... reasonable number of years after first meeting the Administrator's other costs. (ii) The rates must be based...

18 CFR 300.21 - Final confirmation and approval.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Final confirmation and approval. 300.21 Section 300.21 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... reasonable number of years after first meeting the Administrator's other costs. (ii) The rates must be based...

Near-ambient pressure XPS of high-temperature surface chemistry in Sr2Co2O5 thin films

DOE PAGES

Hong, Wesley T.; Stoerzinger, Kelsey; Crumlin, Ethan J.; ...

2016-02-11

Transition metal perovskite oxides are promising electrocatalysts for the oxygen reduction reaction (ORR) in fuel cells, but a lack of fundamental understanding of oxide surfaces impedes the rational design of novel catalysts with improved device efficiencies. In particular, understanding the surface chemistry of oxides is essential for controlling both catalytic activity and long-term stability. Thus, elucidating the physical nature of species on perovskite surfaces and their catalytic enhancement would generate new insights in developing oxide electrocatalysts. In this article, we perform near-ambient pressure XPS of model brownmillerite Sr 2Co 2O 5 (SCO) epitaxial thin films with different crystallographic orientations. Detailedmore » analysis of the Co 2p spectra suggests that the films lose oxygen as a function of temperature. Moreover, deconvolution of the O 1s spectra shows distinct behavior for (114)-oriented SCO films compared to (001)-oriented SCO films, where an additional bulk oxygen species is observed. These findings indicate a change to a perovskite-like oxygen chemistry that occurs more easily in (114) SCO than (001) SCO, likely due to the orientation of oxygen vacancy channels out-of-plane with respect to the film surface. This difference in surface chemistry is responsible for the anisotropy of the oxygen surface exchange coefficient of SCO and may contribute to the enhanced ORR kinetics of La 0.8Sr 0.2CoO 3-δ thin films by SCO surface particles observed previously.« less

The first experimental confirmation of the fractional kinetics containing the complex-power-law exponents: Dielectric measurements of polymerization reactions

NASA Astrophysics Data System (ADS)

Nigmatullin, R. R.; Arbuzov, A. A.; Salehli, F.; Giz, A.; Bayrak, I.; Catalgil-Giz, H.

2007-01-01

For the first time we achieved incontestable evidence that the real process of dielectric relaxation during the polymerization reaction of polyvinylpyrrolidone (PVP) is described in terms of the fractional kinetic equations containing complex-power-law exponents. The possibility of the existence of the fractional kinetics containing non-integer complex-power-law exponents follows from the general theory of dielectric relaxation that has been suggested recently by one of the authors (R.R.N). Based on the physical/geometrical meaning of the fractional integral with complex exponents there is a possibility to develop a general theory of dielectric relaxation based on the self-similar (fractal) character of the reduced (averaged) microprocesses that take place in the mesoscale region. This theory contains some essential predictions related to existence of the non-integer power-law kinetics and the results of this paper can be considered as the first confirmation of existence of the kinetic phenomena that are described by fractional derivatives with complex-power-law exponents. We want to stress here that with the help of a new complex fitting function for the complex permittivity it becomes possible to describe the whole process for real and imaginary parts simultaneously throughout the admissible frequency range (30 Hz-13 MHz). The fitting parameters obtained for the complex permittivity function for three temperatures (70, 90 and 110 °C) confirm in general the picture of reaction that was known qualitatively before. They also reveal some new features, which improve the interpretation of the whole polymerization process. We hope that these first results obtained in the paper will serve as a good stimulus for other researches to find the traces of the existence of new fractional kinetics in other relaxation processes unrelated to the dielectric relaxation. These results should lead to the reconsideration and generalization of irreversibility and kinetic phenomena that

Website Quality, Expectation, Confirmation, and End User Satisfaction: The Knowledge-Intensive Website of the Korean National Cancer Information Center

PubMed Central

Koo, Chulmo; Wati, Yulia; Park, Keeho

2011-01-01

Background The fact that patient satisfaction with primary care clinical practices and physician-patient communications has decreased gradually has brought a new opportunity to the online channel as a supplementary service to provide additional information. Objective In this study, our objectives were to examine the process of cognitive knowledge expectation-confirmation from eHealth users and to recommend the attributes of a “knowledge-intensive website.”. Knowledge expectation can be defined as users’ existing attitudes or beliefs regarding expected levels of knowledge they may gain by accessing the website. Knowledge confirmation is the extent to which user’s knowledge expectation of information systems use is realized during actual use. In our hypothesized research model, perceived information quality, presentation and attractiveness as well as knowledge expectation influence knowledge confirmation, which in turn influences perceived usefulness and end user satisfaction, which feeds back to knowledge expectation. Methods An empirical study was conducted at the National Cancer Center (NCC), Republic of Korea (South Korea), by evaluating its official website. A user survey was administered containing items to measure subjectively perceived website quality and expectation-confirmation attributes. A study sample of 198 usable responses was used for further analysis. We used the structural equation model to test the proposed research model. Results Knowledge expectation exhibited a positive effect on knowledge confirmation (beta = .27, P < .001). The paths from information quality, information presentation, and website attractiveness to knowledge confirmation were also positive and significant (beta = .24, P < .001; beta = .29, P < .001; beta = .18, P < .001, respectively). Moreover, the effect of knowledge confirmation on perceived usefulness was also positively significant (beta = .64, P < .001). Knowledge expectation together with knowledge confirmation

Quantitative assessment of hit detection and confirmation in single and duplicate high-throughput screenings.

PubMed

Wu, Zhijin; Liu, Dongmei; Sui, Yunxia

2008-02-01

The process of identifying active targets (hits) in high-throughput screening (HTS) usually involves 2 steps: first, removing or adjusting for systematic variation in the measurement process so that extreme values represent strong biological activity instead of systematic biases such as plate effect or edge effect and, second, choosing a meaningful cutoff on the calculated statistic to declare positive compounds. Both false-positive and false-negative errors are inevitable in this process. Common control or estimation of error rates is often based on an assumption of normal distribution of the noise. The error rates in hit detection, especially false-negative rates, are hard to verify because in most assays, only compounds selected in primary screening are followed up in confirmation experiments. In this article, the authors take advantage of a quantitative HTS experiment in which all compounds are tested 42 times over a wide range of 14 concentrations so true positives can be found through a dose-response curve. Using the activity status defined by dose curve, the authors analyzed the effect of various data-processing procedures on the sensitivity and specificity of hit detection, the control of error rate, and hit confirmation. A new summary score is proposed and demonstrated to perform well in hit detection and useful in confirmation rate estimation. In general, adjusting for positional effects is beneficial, but a robust test can prevent overadjustment. Error rates estimated based on normal assumption do not agree with actual error rates, for the tails of noise distribution deviate from normal distribution. However, false discovery rate based on empirically estimated null distribution is very close to observed false discovery proportion.

Livers provide a reliable matrix for real-time PCR confirmation of avian botulism.

PubMed

Le Maréchal, Caroline; Ballan, Valentine; Rouxel, Sandra; Bayon-Auboyer, Marie-Hélène; Baudouard, Marie-Agnès; Morvan, Hervé; Houard, Emmanuelle; Poëzevara, Typhaine; Souillard, Rozenn; Woudstra, Cédric; Le Bouquin, Sophie; Fach, Patrick; Chemaly, Marianne

2016-04-01

Diagnosis of avian botulism is based on clinical symptoms, which are indicative but not specific. Laboratory investigations are therefore required to confirm clinical suspicions and establish a definitive diagnosis. Real-time PCR methods have recently been developed for the detection of Clostridium botulinum group III producing type C, D, C/D or D/C toxins. However, no study has been conducted to determine which types of matrices should be analyzed for laboratory confirmation using this approach. This study reports on the comparison of different matrices (pooled intestinal contents, livers, spleens and cloacal swabs) for PCR detection of C. botulinum. Between 2013 and 2015, 63 avian botulism suspicions were tested and 37 were confirmed as botulism. Analysis of livers using real-time PCR after enrichment led to the confirmation of 97% of the botulism outbreaks. Using the same method, spleens led to the confirmation of 90% of botulism outbreaks, cloacal swabs of 93% and pooled intestinal contents of 46%. Liver appears to be the most reliable type of matrix for laboratory confirmation using real-time PCR analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

First confirmed case of Powassan neuroinvasive disease in Rhode Island.

PubMed

Patel, Kavin M; Johnson, Jennie; Zacharioudakis, Ioannis M; Boxerman, Jerrold L; Flanigan, Timothy P; Reece, Rebecca M

2018-01-01

The Powassan Virus is the arthropod-borne vector responsible for Powassan neuroinvasive disease. The virus was first isolated in 1958 and has been responsible for approximately 100 cases of neuroinvasive disease. Rates of infection have been on the rise over the past decade with numerous states reporting their first confirmed case; New Jersey, New Hampshire and Connecticut all reported their first case within the last five years. We present here the first confirmed case of Powassan neuroinvasive disease in the nearby state of Rhode Island. A previously healthy 81-year-old female with known tick exposure presented with fever, altered sensorium, seizures and focal neurological deficits. After an extensive work-up that was largely unrevealing Powassan encephalitis was suspected. The diagnosis was confirmed with serological testing consisting of Powassan IgM enzyme-linked immunosorbent assay and Powassan plaque reduction neutralization testing. The case study provides evidence for the increasing spread of Powassan neuroinvasive disease and reinforces the importance of requesting focused testing for Powassan Virus in patients from an endemic area with a clinically compatible syndrome.

History Detectives Visit NASA Goddard Space Flight Center

NASA Image and Video Library

2017-12-08

The name of the instrument is X-Ray Photoelecton Spectrometer (acronymed XPS); the lab is in the Materials Engineering Branch and aptly titled the X-Ray Photoelectron Spectrometry Lab. XPS is a non-destructive surface analysis technique that provides an elemental composition of the surface. It is capable of detecting any element with the exception of hydrogen and helium. In the picture, I am analyzing a piece of the film that the History Detectives believed was from the Echo II Project. I was looking for the presence of chromium, which would help confirm that the exterior of the film had a chromium conversion coating. PHOTO CREDIT: NASA/Debbie Mccallum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Pragati, E-mail: pkumar.phy@gmail.com; Department of Physics and Astrophysics, University of Delhi, Delhi, 110 007; Saxena, Nupur

This work shows the influence of Ag concentration on structural properties of pulsed laser deposited nanocrystalline CdS thin film. X-ray photoelectron spectroscopy (XPS) studies confirm the dopant concentration in CdS films and atomic concentration of elements. XPS studies show that the samples are slightly sulfur deficient. GAXRD scan reveals the structural phase transformation from cubic to hexagonal phase of CdS without appearance of any phase of CdO, Ag{sub 2}O or Ag{sub 2}S suggesting the substitutional doping of Ag ions. Photoluminescence studies illustrate that emission intensity increases with increase in dopant concentration upto 5% and then decreases for higher dopant concentration.

Battle of the sexes: gender stereotype confirmation and reactance in negotiations.

PubMed

Kray, L J; Thompson, L; Galinsky, A

2001-06-01

The authors examined how gender stereotypes affect negotiation performance. Men outperformed women when the negotiation was perceived as diagnostic of ability (Experiment 1) or the negotiation was linked to gender-specific traits (Experiment 2), suggesting the threat of negative stereotype confirmation hurt women's performance relative to men. The authors hypothesized that men and women confirm gender stereotypes when they are activated implicitly, but when stereotypes are explicitly activated, people exhibit stereotype reactance, or the tendency to behave in a manner inconsistent with a stereotype. Experiment 3 confirmed this hypothesis. In Experiment 4, the authors examined the cognitive processes involved in stereotype reactance and the conditions under which cooperative behaviors between men and women can be promoted at the bargaining table (by activating a shared identity that transcends gender).

Outcomes and management of patients with Cushing's disease without pathological confirmation of tumor resection after transsphenoidal surgery.

PubMed

Pouratian, Nader; Prevedello, Daniel M; Jagannathan, Jay; Lopes, M Beatriz; Vance, Mary Lee; Laws, Edward R

2007-09-01

Despite the success of transsphenoidal surgery (TSS) for the treatment of Cushing's disease, in a number of cases, an ACTH-staining pituitary adenoma is not identified histologically. The clinical significance of lack of histological confirmation remains unclear. This was a retrospective review of patients treated at the University of Virginia Medical Center. Of 490 TSS procedures for Cushing's disease between 1993 and 2004, we identified 111 cases without histological adenoma confirmation. Remission and recurrence of Cushing's disease were measured. Overall, 50% of these patients achieved remission, a figure lower than for our entire series (79%) and for patients with histological confirmation of an ACTH-staining adenoma (88%) (P < 0.001). Patients with a history of two prior TSS achieved remission less often than patients with a history of fewer TSS (P = 0.026). No other factors influenced remission rates. Although the overall recurrence rate (21%, seven of 33 evaluated) was not different from previously published long-term studies, in three of seven cases of recurrence, early recurrences were noted between 2 and 4 months after remission. In patients who did not achieve remission, the most common and effective treatment options were repeat TSS, gamma-knife radiosurgery, and bilateral adrenalectomy. The lower remission rate in patients without histological evidence of an adenoma is most likely a result of a decreased rate of adenoma extirpation. The incidence of early recurrence may be a unique feature of this patient population; patients without histological confirmation of tumor resection therefore require close and consistent monitoring postoperatively.

Space Weathering of Silicates Simulated by Successive Laser Irradiation: in Situ Reflectance Measurements of Fo90, Fo99+, and SiO2

NASA Technical Reports Server (NTRS)

Loeffler, M. J.; Dukes, C. A.; Christoffersen, R.; Baragiola, R. A.

2016-01-01

Pulsed-laser irradiation causes the visible-near-infrared spectral slope of olivine (Fo90 and Fo99+) and SiO2 to increase (redden), while the olivine samples darken and the SiO2 samples brighten slightly. XPS analysis shows that irradiation of Fo90 produces metallic Fe. Analytical SEM and TEM measurements confirm that reddening in the Fo90 olivine samples correlates with the production of "nanophase" metallic Fe (npFe0) grains, 20-50 nm in size. The reddening observed in the SiO2 sample is consistent with the formation of SiO or other SiOx species that absorb in the visible. The weak spectral brightening induced by laser irradiation of SiO2 is consistent with a change in surface topography of the sample. The darkening observed in the olivine samples is likely caused by the formation of larger npFe0 particles, such as the 100-400 nm diameter npFe0 identified during our TEM analysis of Fo90 samples. The Fo90 reflectance spectra are qualitatively similar to those in previous experiments suggesting that in all cases formation of npFe0 is causing the spectral alteration. Finally, we find that the accumulation of successive laser pulses cause continued sample darkening in the Vis-NIR, which suggests that repeated surface impacts are an efficient way to darken airless body surfaces.

Facile fabrication of BiVO4 nanofilms with controlled pore size and their photoelectrochemical performances

NASA Astrophysics Data System (ADS)

Feng, Chenchen; Jiao, Zhengbo; Li, Shaopeng; Zhang, Yan; Bi, Yingpu

2015-12-01

We demonstrate a facile method for the rational fabrication of pore-size controlled nanoporous BiVO4 photoanodes, and confirmed that the optimum pore-size distributions could effectively absorb visible light through light diffraction and confinement functions. Furthermore, in situ X-ray photoelectron spectroscopy (XPS) reveals more efficient photoexcited electron-hole separation than conventional particle films, induced by light confinement and rapid charge transfer in the inter-crossed worm-like structures.We demonstrate a facile method for the rational fabrication of pore-size controlled nanoporous BiVO4 photoanodes, and confirmed that the optimum pore-size distributions could effectively absorb visible light through light diffraction and confinement functions. Furthermore, in situ X-ray photoelectron spectroscopy (XPS) reveals more efficient photoexcited electron-hole separation than conventional particle films, induced by light confinement and rapid charge transfer in the inter-crossed worm-like structures. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06584d

Visual Confirmation of Voice Takeoff Clearance (VICON) Alternative Study

DOT National Transportation Integrated Search

1980-05-01

This report presents the results of a program undertaken to study potential alternatives to the VICON (Visual Confirmation of Voice Takeoff Clearance) System which has undergone operational field tests at Bradley International Airport, Windsor Locks,...

Subjective anxiety and behavioral avoidance: Gender, gender role, and perceived confirmability of self-report.

PubMed

McLean, Carmen P; Hope, Debra A

2010-06-01

Commonly reported gender effects for differential vulnerability for anxiety may relate to gender socialization processes. The present study examined the relationship between gender role and fear under experimental conditions designed to elicit accurate fear reporting. Undergraduate students (N=119) completed several self-report measures and a behavioral avoidance task (BAT) with a tarantula while wearing a heart rate monitor. Gender roles were operationalized as instrumentality and expressiveness, as measured by the Personal Attributes Questionnaire (Spence, Helmreich, & Stapp, 1975). As expected, women reported greater subjective anxiety and were more avoidant of the tarantula than men. Regardless of gender, low levels of instrumentality were associated with greater avoidance of the tarantula. The hypothesis that men underreport fear compared to women and that gender role differences underlie this reporting bias was not supported. In spite of a ceiling effect on the BAT, results of this study confirm the relevance of gender role in understanding gender effects in fear and anxiety. Copyright 2010 Elsevier Ltd. All rights reserved.

Facile and fast synthesis of SnS2 nanoparticles by pulsed laser ablation in liquid

NASA Astrophysics Data System (ADS)

Johny, J.; Sepulveda-Guzman, S.; Krishnan, B.; Avellaneda, D.; Shaji, S.

2018-03-01

Nanoparticles (NPs) of tin disulfide (SnS2) were synthesized using pulsed laser ablation in liquid (PLAL) technique. Effects of different liquid media and ablation wavelengths on the morphology and optical properties of the nanoparticles were studied. Nd: YAG laser wavelengths of 532 nm and 1064 nm (frequency 10 Hz and pulse width 10 ns) were used to irradiate SnS2 target immersed in liquid for the synthesis of SnS2 nanoparticles. Here PLAL was a fast synthesis technique, the ablation was only for 30 s. Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, UV-vis absorption spectroscopy and photoluminescence spectroscopy were used to characterize the SnS2 NPs. TEM images showed that the liquid medium and laser wavelength influence the morphology of the NPs. SAED patterns and high resolution TEM (HRTEM) images confirmed the crystallinity of the particles. XRD and XPS analyses confirmed that SnS2 NPs were having exact crystalline structure and chemical states as that of the target. Raman analysis also supported the results obtained by XRD and XPS. Optical band gaps of the nanocolloids evaluated from their UV-vis absorption spectra were 2.4-3.05 eV. SnS2 NPs were having luminescence spectra in the blue-green region irrespective of the liquid media and ablation wavelength.

Characterization and measurement of polymer wear

NASA Technical Reports Server (NTRS)

Buckley, D. H.; Aron, P. R.

1984-01-01

Analytical tools which characterize the polymer wear process are discussed. The devices discussed include: visual observation of polymer wear with SEM, the quantification with surface profilometry and ellipsometry, to study the chemistry with AES, XPS and SIMS, to establish interfacial polymer orientation and accordingly bonding with QUARTIR, polymer state with Raman spectroscopy and stresses that develop in polymer films using a X-ray double crystal camera technique.

Adsorption differences between low coverage enantiomers of alanine on the chiral Cu{421}R surface.

PubMed

Gladys, Michael J; Han, Jeong Woo; Pedersen, Therese S; Tadich, Anton; O'Donnell, Kane M; Thomsen, Lars

2017-05-31

Chiral separation using heterogeneous methods has long been sought after. Chiral metal surfaces have the potential to make it possible to model these systems using small amino acids, the building blocks for proteins. A comparison of submonolayer concentrations of alanine enantiomers adsorbed onto Cu{421} R has revealed a large geometrical differences between the two molecules as compared to the saturated coverage. Large differences were observed in HR-XPS and NEXAFS and complemented by theoretical DFT calculations. At approximately one third of a monolayer a comparison of the C1s XPS signal showed a shift in the methyl group of more than 300 meV indicating that the two enantiomers are in different chemical environments. NEXAFS spectroscopy confirmed the XPS variations and showed large differences in the orientation of the adsorbed molecules. Our DFT results show that the l-enantiomer is energetically the most stable in the {311} microfacet configuration. In contrast to the full monolayer coverage, these lower coverages showed enhanced selectivity.

Enhancing electrochemical water-splitting kinetics by polarization-driven formation of near-surface iron(0): an in situ XPS study on perovskite-type electrodes.

PubMed

Opitz, Alexander K; Nenning, Andreas; Rameshan, Christoph; Rameshan, Raffael; Blume, Raoul; Hävecker, Michael; Knop-Gericke, Axel; Rupprechter, Günther; Fleig, Jürgen; Klötzer, Bernhard

2015-02-23

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 La0.6 Sr0.4 FeO3-δ (LSF) thin film electrodes. Under cathodic polarization the formation of Fe(0) 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. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

NIH study confirms risk factors for male breast cancer

Cancer.gov

Pooled data from studies of about 2,400 men with breast cancer and 52,000 men without breast cancer confirmed that risk factors for male breast cancer include obesity, a rare genetic condition called Klinefelter syndrome, and gynecomastia.

Demonstration of an ultrasensitive refractive-index plasmonic sensor by enabling its quadrupole resonance in phase interrogation.

PubMed

Lee, Hsin-Cheng; Li, Chung-Tien; Chen, How-Foo; Yen, Ta-Jen

2015-11-15

We present an ultrasensitive plasmonic sensing system by introducing a nanostructured X-shaped plasmonic sensor (XPS) and measuring its localized optical properties in phase interrogation. Our tailored XPS exhibits two major resonant modes of a low-order dipole and a high-order quadrupole, between which the quadrupole resonance allows an ultrahigh sensitivity, due to its higher quality factor. Furthermore, we design an in-house common-path phase-interrogation system, in contrast to conventional wavelength-interrogation methods, to achieve greater sensing capability. The experimental measurement shows that the sensing resolution of the XPS reaches 1.15×10(-6) RIU, not only two orders of magnitude greater than the result of the controlled extinction measurement (i.e., 9.90×10(-5) RIU), but also superior than current reported plasmonic sensors.

Location of Varying Hydrophobicity Zinc(II) Phthalocyanine-Type Photosensitizers in Methoxy Poly(ethylene oxide) and Poly(l-lactide) Block Copolymer Micelles Using 1H NMR and XPS Techniques.

PubMed

Lamch, Łukasz; Tylus, Włodzimierz; Jewgiński, Michał; Latajka, Rafał; Wilk, Kazimiera A

2016-12-15

Hydrophobic zinc(II) phthalocyanine-type derivatives, solubilized in polymeric micelles (PMs), provide a befitting group of so-called nanophotosensitizers, suitable for a variety of photodynamic therapy (PDT) protocols. The factors that influence the success of such products in PDT are the location of the active cargo in the PMs and the nanocarrier-enhanced ability to safely interact with biological systems and fulfill their therapeutic functions. Therefore, the aim of this work was to determine the solubilization loci of three phthalocyanines of varying hydrophobicity, i.e., zinc(II) phthalocyanine (ZnPc), along with its tetrasulfonic acid (ZnPc-sulfo 4 ) and perfluorinated (ZnPcF 16 ) derivatives, loaded in polymeric micelles of methoxy poly(ethylene oxide)-b-poly(l-lactide) (mPEG-b-PLLA), by means of 1 H nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) combined with ion sputtering. Furthermore, the microenvironment influence upon the chemical and physical status of the solubilized cargo in PMs, expressed by photobleaching and reactive oxygen species (ROS) generation comparing to the same properties of native cargoes in solution, was also evaluated and discussed in regards to the probing location data. The studied phthalocyanine-loaded PMs exhibited good physical stability, high drug-loading efficiency, and a size of less than ca. 150 nm with low polydispersity indices. The formation of polymeric micelles and the solubilization locus were investigated by 1 H NMR and XPS. ZnPc localized within the PM core, whereas both ZnPcF 16 and ZnPc-sulfo 4 - in the corona of PMs. We proved that the cargo locus is crucial for the photochemical properties of the studied phthalocyanines; the increase in photostability and ability to generate ROS in micellar solution compared to free photosensitizer was most significant for the photosensitizer in the PM core. Our results indicate the role of the cargo location in the PM microenvironment and demonstrate

Resolved versus confirmed ARDS after 24 h: insights from the LUNG SAFE study.

PubMed

Madotto, Fabiana; Pham, Tài; Bellani, Giacomo; Bos, Lieuwe D; Simonis, Fabienne D; Fan, Eddy; Artigas, Antonio; Brochard, Laurent; Schultz, Marcus J; Laffey, John G

2018-04-09

To evaluate patients with resolved versus confirmed ARDS, identify subgroups with substantial mortality risk, and to determine the utility of day 2 ARDS reclassification. Our primary objective, in this secondary LUNG SAFE analysis, was to compare outcome in patients with resolved versus confirmed ARDS after 24 h. Secondary objectives included identifying factors associated with ARDS persistence and mortality, and the utility of day 2 ARDS reclassification. Of 2377 patients fulfilling the ARDS definition on the first day of ARDS (day 1) and receiving invasive mechanical ventilation, 503 (24%) no longer fulfilled the ARDS definition the next day, 52% of whom initially had moderate or severe ARDS. Higher tidal volume on day 1 of ARDS was associated with confirmed ARDS [OR 1.07 (CI 1.01-1.13), P = 0.035]. Hospital mortality was 38% overall, ranging from 31% in resolved ARDS to 41% in confirmed ARDS, and 57% in confirmed severe ARDS at day 2. In both resolved and confirmed ARDS, age, non-respiratory SOFA score, lower PEEP and P/F ratio, higher peak pressure and respiratory rate were each associated with mortality. In confirmed ARDS, pH and the presence of immunosuppression or neoplasm were also associated with mortality. The increase in area under the receiver operating curve for ARDS reclassification on day 2 was marginal. ARDS, whether resolved or confirmed at day 2, has a high mortality rate. ARDS reclassification at day 2 has limited predictive value for mortality. The substantial mortality risk in severe confirmed ARDS suggests that complex interventions might best be tested in this population. ClinicalTrials.gov NCT02010073.

Optical confirmation of Gaia18ayp brightness increase

NASA Astrophysics Data System (ADS)

Spano, M.; Blanco-Cuaresma, S.; Roelens, M.; Mowlavi, N.; Eyer, L.

2018-04-01

We report confirmation of Gaia_Science_Alerts, brightness increase of the QSO [VV2006] J233633.0-411547, Gaia18ayp . Images were obtained through modified Gunn R and V band filter of the ECAM instrument installed on the Swiss 1.2m Euler telescope at La Silla, on 2018 April 21- 22. Magnitudes according to the MJD of observations.

Confirmation of thalamosubthalamic projections by electron microscopic autoradiography.

PubMed

Sugimoto, T; Hattori, T

1983-05-16

Direct projections from the centre median-parafascicular complex (CM-Pf) to the subthalamic nucleus(STN) were confirmed by electron microscopic autoradiography. [3H]Leucine injections into the rat CM-Pf produced preferential labeling of Gray's type I boutons containing round vesicles in the ipsilateral STN. Further results strongly suggested the existence of some common CM-Pf projections to both the striatum and STN.

Confirmational study: a positive-based thumb and finger sucking elimination program.

PubMed

Green, Shari E

2010-11-01

This article emphasizes the critical need for information specifically regarding the topic of retained sucking behaviors. The study aimed to confirm results provided by Van Norman of 723 subjects in 1997. Parent surveys were collected on 441 subjects who received an orofacial myofunctional treatment program provided by one certified orofacial myologist. Results of this study do confirm that retained digit sucking behavior may be addressed successfully and expediently by a program based on positive behavior modification techniques.

Preparation and Characterization of Polyurethanes with Cross-Linked Siloxane in the Side Chain by Sol-Gel Reactions

PubMed Central

Zhao, Hui; Hao, Tong-Hui; Hu, Guo-Hua; Shi, Dean; Huang, Da; Jiang, Tao; Zhang, Qun-Chao

2017-01-01

A series of novel polyurethanes containing cross-linked siloxane in the side chain (SPU) were successfully synthesized through a sol-gel process. The SPU was composed of 0%–20% N-(n-butyl)-3-aminopropyltriethoxysilane (HDI-T) modified hexamethylene diisocynate homopolymer. The effects of HDI-T content on both the structure and properties of SPU were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), mechanical properties tests, gel content test, water contact angle measurement and water absorption test. FT-IR, XPS and XRD results confirmed the successful incorporation of HDI-T onto polyurethanes and the formation of Si–O–Si. The surface roughness and the Si content of SPU enhanced with the increase of HDI-T content. Both crystallization and melting temperature shifted to a lower point after the incorporation of HDI-T. The hydrophobicity, tensile strength, Young’s modulus and pencil hardness overall increased with the increasing of HDI-T content, whereas the thermal stability and the elongation at break of SPU slightly decreased. PMID:28772607

Effects of SF6 plasma treatment on the properties of InGaZnO thin films

NASA Astrophysics Data System (ADS)

Choi, Jinsung; Bae, Byung Seong; Yun, Eui-Jung

2018-03-01

The effects of sulfur hexafluoride (SF6) plasma on the properties of amorphous InGaZnO (a-IGZO) thin films were examined. The properties of the a-IGZO thin films were characterized by Hall effect measurement, dynamic secondary ion mass spectroscopy (SIMS), and X-ray photoelectron spectroscopy (XPS). The IGZO thin films treated with SF6 plasma before annealing had a very high resistance mainly owing to the inclusion of S into the film surface, as evidenced by SIMS profiles. On the other hand, the samples treated with SF6 plasma after annealing showed better electrical properties with a Hall mobility of 10 cm2/(V·s) than the untreated samples or the samples SF6 plasma-treated before annealing. This was attributed to the increase in the number of oxygen vacancy defects in the a-IGZO thin films owing to the enhanced out-diffusion of O to the ambient and the increase in the number of F-related donor defects originating from the incorporation of a much larger amount of F than of S into the film surface, which were confirmed by XPS and SIMS.

Incommensurate growth of Co thin film on close-packed Ag(111) surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barman, Sukanta, E-mail: sukanta.ac@gmail.com; Menon, Krishna Kumar S. R., E-mail: krishna.menon@saha.ac.in

2016-05-06

Growth of ultrathin Co layers on close-packed Ag(111)were investigated by means of Low Energy Electron Diffraction (LEED), X-ray Photoelectron Spectroscopy (XPS) and Angle-resolved Photoemission Spectroscopy(ARPES) techniques. The close-packed hexagonal face of Co(0001), exhibits a lattice misfit about 13% with Ag(111) surface which manipulates the growth to be incommensurate up to a certain thickness. The strain field causes aperiodic height undulation in the sub-angstrom regime of the film which was confirmed by p(1 × 1) LEED pattern along with a 6-fold moiré reconstruction pattern in the lower film thickness (up to ∼2ML). The evolution of the LEED pattern was studied withmore » increasing film coverage. Lattice strain was measured with respect to the relative positions of these double spots as a functionof film thickness. Almost a constant strain (∼13%) in the full range of film thickness explains the moiré pattern formation in order to stabilize the incommensurate growth. For higher film coverages, an epitaxial well-ordered commensurate growth was observed. Core level and valance band electronic structures of these films were studied by XPS and ARPES techniques.« less

Confirmation of Maslow's Hypothesis of Synergy: Developing an Acceptance of Selfishness at the Workplace Scale.

PubMed

Takaki, Jiro; Taniguchi, Toshiyo; Fujii, Yasuhito

2016-04-30

This study aimed to develop a new Acceptance of Selfishness at the Workplace Scale (ASWS) and to confirm Maslow's hypothesis of synergy: if both a sense of contribution and acceptance of selfishness at the workplace are high, workers are psychologically healthy. In a cross-sectional study with employees of three Japanese companies, 656 workers answered a self-administered questionnaire on paper completely (response rate = 66.8%). Each questionnaire was submitted to us in a sealed envelope and analyzed. The ASWS indicated high internal consistency (Cronbach's alpha = 0.86). Significant (p < 0.001) positive moderate correlations between ASWS scores and job control scores support the ASWS's convergent and discriminant validity. Significant (p < 0.001) associations of ASWS scores with psychological distress and work engagement supported the ASWS's criterion validity. In short, ASWS was a psychometrically satisfactory measure. Significant (p < 0.05) interactions between a sense of contribution and acceptance of selfishness at the workplace in linear regression models showed that when those two factors are low, psychological distress becomes high. However, when a sense of contribution and acceptance of selfishness are high, work engagement also becomes high. Thus, Maslow's hypothesis of synergy was confirmed.

TESS Follow-up Observing Program (TFOP) Working Group:A Mission-led Effort to Coordinate Community Resources to Confirm TESS Planets

NASA Astrophysics Data System (ADS)

Collins, Karen; Quinn, Samuel N.; Latham, David W.; Christiansen, Jessie; Ciardi, David; Dragomir, Diana; Crossfield, Ian; Seager, Sara

2018-01-01

The Transiting Exoplanet Survey Satellite (TESS) will observe most of the sky over a period of two years. Observations will be conducted in 26 sectors of sky coverage and each sector will be observed for ~27 days. Data from each sector is expected to produce hundreds of transiting planet candidates (PCs) per month and thousands over the two year nominal mission. The TFOP Working Group (WG) is a mission-led effort organized to efficiently provide follow-up observations to confirm candidates as planets or reject them as false positives. The primary goal of the TFOP WG is to facilitate achievement of the Level One Science Requirement to measure masses for 50 transiting planets smaller than 4 Earth radii. Secondary goals are to serve any science coming out of TESS and to foster communication and coordination both within the TESS Science Team and with the community at large. The TFOP WG is organized as five Sub Groups (SGs). SG1 will provide seeing-limited imaging to measure blending within a candidate's aperture and time-series photometry to identify false positives and in some cases to improve ephemerides, light curves, and/or transit time variation (TTV) measurements. SG2 will provide reconnaissance spectroscopy to identify astrophysical false positives and to contribute to improved host star parameters. SG3 will provide high-resolution imaging with adaptive optics, speckle imaging, and lucky imaging to detect nearby objects. SG4 will provide precise radial velocities to derive orbits of planet(s) and measure their mass(es) relative to the host star. SG5 will provide space-based photometry to confirm and/or improve the TESS photometric ephemerides, and will also provide improved light curves for transit events or TTV measurements. We describe the TFOP WG observing and planet confirmation process, the five SGs that comprise the TFOP WG, ExoFOP-TESS and other web-based tools being developed to support TFOP WG observers, other advantages of joining the TFOP WG, the TFOP

The use of ambulatory blood pressure monitoring to confirm a diagnosis of high blood pressure by primary-care physicians in Oregon.

PubMed

Carter, Brittany U; Kaylor, Mary Beth

2016-04-01

Hypertension is the most commonly diagnosed medical condition in the USA. Unfortunately, patients are misdiagnosed in primary care because of inaccurate office-based blood pressure measurements. Several US healthcare organizations currently recommend confirming an office-based hypertension diagnosis with ambulatory blood pressure monitoring to avoid overtreatment; however, its use for the purpose of confirming an office-based hypertension diagnosis is relatively unknown. This descriptive study surveyed 143 primary-care physicians in Oregon with regard to their current use of ambulatory blood pressure monitoring. Nineteen percent of the physicians reported that they would use ambulatory blood pressure monitoring to confirm an office-based hypertension diagnosis, although over half had never ordered it. The most frequent indication for ordering ambulatory blood pressure monitoring was to investigate suspected white-coat hypertension (37.3%). In addition, many of the practices did not own an ambulatory blood pressure monitoring device (79.7%) and, therefore, had to refer patients to other clinics or departments for testing. Many primary-care physicians will need to change their current clinical practice to align with the shift toward a confirmation process for office-based hypertension diagnoses to improve population health.

49 CFR 40.251 - What are the first steps in an alcohol confirmation test?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false What are the first steps in an alcohol... What are the first steps in an alcohol confirmation test? As the BAT for an alcohol confirmation test, you must follow these steps to begin the confirmation test process: (a) You must carry out a...

Experimental confirmation of stable, small-debye-length, pure-electron-plasma equilibria in a stellarator.

PubMed

Kremer, J P; Pedersen, T Sunn; Lefrancois, R G; Marksteiner, Q

2006-09-01

The creation of the first small-Debye length, low temperature pure electron plasmas in a stellarator is reported. A confinement time of 20 ms has been measured. The long confinement time implies the existence of macroscopically stable equilibria and that the single particle orbits are well confined despite the lack of quasisymmetry in the device, the Columbia non-neutral torus. This confirms the beneficial confinement effects of strong electric fields and the resulting rapid E x B rotation of the electrons. The particle confinement time is presently limited by the presence of bulk insulating materials in the plasma, rather than any intrinsic plasma transport processes. A nearly flat temperature profile is seen in the inner part of the plasma.

18 CFR 300.10 - Application for confirmation and approval.

Code of Federal Regulations, 2010 CFR

2010-04-01

... REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS FOR FEDERAL POWER MARKETING ADMINISTRATIONS CONFIRMATION AND APPROVAL OF THE RATES OF FEDERAL POWER MARKETING ADMINISTRATIONS Filing Requirements § 300.10... with applicable laws and that it is the lowest possible rate consistent with sound business principles...

Multicharged Ion Promoted Desorption (MIPD) of Reaction Co-Products

DTIC Science & Technology

2015-02-13

measurements of surface modifications using mass spectrometry, Raman spectroscopy and XPS were made to 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND...desorption and ex-situ measurements of surface modifications using mass spectrometry, Raman spectroscopy and XPS were made to determine ion-induced...irradiations were made with the samples at normal incidence to the incoming beams and post-analysis of these samples was achieved using Raman spectroscopy. It

Titanium composite conversion coating formation on CRS In the presence of Mo and Ni ions: Electrochemical and microstructure characterizations

NASA Astrophysics Data System (ADS)

Eivaz Mohammadloo, H.; Sarabi, A. A.

2016-11-01

There have been an increasing interest in finding a replacement for the chromating process due to environmental and health concerns. Hence, in this study Chrome-free chemical conversion coatings were deposited on the surface of cold-rolled steel (CRS) on the basis of Titanium (TiCC), Titanium-Nickel (TiNiCC) and titanium-molybdate (TiMoCC) based conversion coating solutions. The surface characterization was performed by field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measuring device. Also, the corrosion behavior was assessed by the means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. FESEM and AFM study show that the TiNiCC is denser and more uniform than that TiCC and TiMoCC since, TiMoCC conversion coating presents network feature, and there were abundant micro-cracks on the surface of the coating. XPS results confirmed the precipitation of Ti and Ni oxide/hydroxide, Mn dioxide/trioxide on the surface of different Ti-based conversion coatings. Electrochemical results revealed that all Ti-based conversion coatings have better anti-corrosion properties than bare CRS. Moreover, TiNiCC treatment inhibited the corrosion of CRS to a significant degree (polarization resistance (Rp) = 5510 Ω cm2) in comparison with TiCC (Rp = 2705 Ω cm2) and TiMoCC (Rp = 805 Ω cm2).

Proteomics-Derived Cerebrospinal Fluid Markers of Autopsy-Confirmed Alzheimer’s Disease

PubMed Central

Roher, Alex E.; Maarouf, Chera L.; Sue, Lucia I.; Hu, Yiran; Wilson, Jeffrey; Beach, Thomas G.

2010-01-01

The diagnostic performance of several candidate cerebrospinal fluid (CSF) protein biomarkers of neuropathologically-confirmed Alzheimer’s disease (AD), non-demented (ND) elderly controls and non-AD dementias (NADD) was assessed. Candidate markers were selected on the basis of initial 2-dimensional gel electrophoresis studies or by literature review. Markers selected by the former method included apolipoprotein A-1 (ApoA1), hemopexin (HPX), transthyretin (TTR) and pigment epithelium-derived factor (PEDF) while markers identified from the literature included Aβ1–40, Aβ1–42, total tau, phosphorylated tau, α-1 acid glycoprotein (A1GP), haptoglobin, zinc α-2 glycoprotein (Z2GP) and apolipoprotein E (ApoE). Ventricular CSF concentrations of the markers were measured by ELISA. The concentrations of Aβ1–42, ApoA1, A1GP, ApoE, HPX and Z2GP differed significantly among AD, ND and NADD subjects. Logistic regression analysis for the diagnostic discrimination of AD from ND found that Aβ1–42, ApoA1 and HPX each had significant and independent associations with diagnosis. The CSF concentrations of these three markers distinguished AD from ND subjects with 84% sensitivity and 72% specificity, with 78% of subjects correctly classified. By comparison, using Aβ1–42 alone gave 79% sensitivity and 61% specificity, with 68% of subjects correctly classified. For the diagnostic discrimination of AD from NADD, only the concentration of Aβ1–42 was significantly related to diagnosis, with a sensitivity of 58%, specificity of 86% and 86% correctly classified. The results indicate that for the discrimination of AD from ND control subjects, measurement of a set of markers including Aβ1–42, ApoA1 and HPX improved diagnostic performance over that obtained by measurement of Aβ1–42 alone. For the discrimination of AD from NADD subjects, measurement of Aβ1–42 alone was superior. PMID:19863188

Structural, magnetic, dielectric, and electrical properties of NiFe2O4 spinel ferrite nanoparticles prepared by honey-mediated sol-gel combustion

NASA Astrophysics Data System (ADS)

Yadav, Raghvendra Singh; Kuřitka, Ivo; Vilcakova, Jarmila; Havlica, Jaromir; Masilko, Jiri; Kalina, Lukas; Tkacz, Jakub; Enev, Vojtěch; Hajdúchová, Miroslava

2017-08-01

In this study, NiFe2O4 nanoparticles were synthesized using a honey-mediated sol-gel combustion method. The synthesized nanoparticles and samples annealed at 800 °C and 1100 °C were characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). XRD and Raman spectroscopy confirmed the formation of a cubic spinel ferrite structure. FE-SEM demonstrated the octahedral morphology of the NiFe2O4 spinel ferrite nanoparticles with sizes ranging from 10 to 70 nm. Quantitative analysis based on XPS suggested a mixed spinel structure comprising NiFe2O4 nanoparticles. XPS analysis determined occupation formulae of (Ni0.212+ Fe0.443+)[Ni0.792+ Fe1.563+]O4 and (Ni0.232+ Fe0.503+)[Ni0.772+ Fe1.503+]O4, for the as-prepared NiFe2O4 nanoparticles and those annealed at 1100 °C, respectively. Magnetic measurements showed that the saturation magnetization increased with the crystallite size from 32.3 emu/g (20 nm) to 49.9 emu/g (163 nm), whereas the coercivity decreased with the crystallite size from 162 Oe (20 nm) to 47 Oe (163 nm). Furthermore, the dielectric constant, dielectric loss tangent, and AC conductivity of the NiFe2O4 nanoparticles were dependent on the frequency (1-107 Hz) and grain size. The influence of the grain size was also observed by modulus spectroscopy based on the Cole-Cole plot.

Diabetes services in the UK: third national survey confirms continuing deficiencies.

PubMed

Jefferson, I G; Swift, P G F; Skinner, T C; Hood, G K

2003-01-01

To determine the current level of diabetes services and to compare the results with previous national surveys. A questionnaire was mailed to all paediatricians in the UK identified as providing care for children with diabetes aged under 16 years. Information was sought on staffing, personnel, clinic size, facilities, and patterns of care. Responses were compared with results of two previous national surveys. Replies were received from 244 consultant paediatricians caring for an estimated 17 192 children. A further 2234 children were identified as being cared for by other consultants who did not contribute to the survey. Of 244 consultants, 78% expressed a special interest in diabetes and 91% saw children in a designated diabetic clinic. In 93% of the clinics there was a specialist nurse (44% were not trained to care for children; 47% had nurse:patient ratio >1:100), 65% a paediatric dietitian, and in 25% some form of specialist psychology or counselling available. Glycated haemoglobin was measured routinely at clinics in 88%, retinopathy screening was performed in 87%, and microalbuminuria measured in 66%. Only 34% consultants used a computer database. There were significant differences between the services provided by paediatricians expressing a special interest in diabetes compared with "non-specialists", the latter describing less frequent clinic attendance of dietitians or psychologists, less usage of glycated haemoglobin measurements, and less screening for vascular complications. Non-specialist clinics met significantly fewer of the recommendations of good practice described by Diabetes UK. The survey shows improvements in services provided for children with diabetes, but serious deficiencies remain. There is a shortage of diabetes specialist nurses trained to care for children and paediatric dietitians, and a major shortfall in the provision of psychology/counselling services. The services described confirm the need for more consultant paediatricians to

Surface modification of EPDM rubber by plasma treatment.

PubMed

Grythe, Kai Frode; Hansen, Finn Knut

2006-07-04

The effect of argon, oxygen, and nitrogen plasma treatment of solvent cast EPDM rubber films has been investigated by means of atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and surface energy measurements. Plasma treatment leads to changes in the surface energy from 25 to 70 mN/m. Treatment conditions influenced both the changes in surface energy and the stability, and it became more difficult to obtain good contact angle measurements after longer (> ca. 4 min) treatment times, probably because of an increasingly uneven surface structure. XPS analyses revealed that up to 20 at. % oxygen can be easily incorporated and that variations of approximately 5% can be controlled by the plasma conditions. Oxygen was mainly found in hydroxyl groups, but also as carbonyl and carboxyl. XPS analyses showed more stable surfaces than expected from contact angles, probably because XPS analysis is less surface sensitive than contact angle measurements. AFM measurements revealed different surface structures with the three gases. The surface roughness increased generally with treatment time, and dramatic changes could be observed at longer times. At short times, surface energy changes were much faster than the changes in surface structure, showing that plasma treatment conditions can be utilized to tailor both surface energies and surface structure of EPDM rubber.

Infrared reduction, an efficient method to control the non-linear optical property of graphene oxide in femtosecond regime

NASA Astrophysics Data System (ADS)

Bhattacharya, S.; Maiti, R.; Saha, S.; Das, A. C.; Mondal, S.; Ray, S. K.; Bhaktha, S. B. N.; Datta, P. K.

2016-04-01

Graphene Oxide (GO) has been prepared by modified Hummers method and it has been reduced using an IR bulb (800-2000 nm). Both as grown GO and reduced graphene oxide (RGO) have been characterized using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectra shows well documented Dband and G-band for both the samples while blue shift of G-band confirms chemical functionalization of graphene with different oxygen functional group. The XPS result shows that the as-prepared GO contains 52% of sp2 hybridized carbon due to the C=C bonds and 33% of carbon atoms due to the C-O bonds. As for RGO, increment of the atomic % of the sp2 hybridized carbon atom to 83% and rapid decrease in atomic % of C=O bonds confirm an efficient reduction with infrared radiation. UV-Visible absorption spectrum also confirms increment of conjugation with increased reduction. Non-linear optical properties of both GO and RGO are measured using single beam open aperture Z-Scan technique in femtosecond regime. Intensity dependent nonlinear phenomena are observed. Depending upon the intensity, both saturable absorption and two photon absorption contribute to the non-linearity of both the samples. Saturation dominates at low intensity (~ 127 GW/cm2) while two photon absorption become prominent at higher intensities (from 217 GW/cm2 to 302 GW/cm2). We have calculated the two-photon absorption co-efficient and saturation intensity for both the samples. The value of two photon absorption co-efficient (for GO~ 0.0022-0.0037 cm/GW and for RGO~ 0.0128-0.0143 cm/GW) and the saturation intensity (for GO~57 GW/cm2 and for RGO~ 194GW/cm2) is increased with reduction. Increase in two photon absorption coefficient with increasing intensity can also suggest that there may be multi-photon absorption is taking place.

Microstructural, electrical and frequency-dependent properties of Au/p-Cu2ZnSnS4/n-GaN heterojunction.

PubMed

Rajagopal Reddy, V; Janardhanam, V; Won, Jonghan; Choi, Chel-Jong

2017-08-01

An Au/Cu 2 ZnSnS 4 (CZTS)/n-GaN heterojunction (HJ) is fabricated with a CZTS interlayer and probed its chemical states, structural, electrical and frequency-dependent characteristics by XPS, TEM, I-V and C-V measurements. XPS and TEM results confirmed that the CZTS films are formed on the n-GaN surface. The band gap of deposited CZTS film is found to be 1.55eV. The electrical properties of HJ correlated with the Au/n-GaN Schottky junction (SJ). The Au/CZTS/n-GaN HJ reveals a good rectification nature with high barrier height (0.82eV) compared to the Au/n-GaN SJ (0.69eV), which suggests the barrier height is influenced by the CZTS interlayer. The barrier height values assessed by I-V, Cheung's and Norde functions are closely matched with one other, thus the methods used here are reliable and valid. The extracted interface state density (N SS ) of Au/CZTS/n-GaN HJ is lower compared to the Au/n-GaN SJ that suggests the CZTS interlayer plays an important role in the reduction of N SS . Moreover, the capacitance-frequency (C-f) and conductance-frequency (G-f) characteristics of SJ and HJ are measured in the range of 1kHz-1MHz, and found that the capacitance and conductance strappingly dependent on frequency. It is found that the N SS estimated from C-f and G-f characteristics is lower compared to those estimated from I-V characteristics. Analysis confirmed that Poole-Frenkel emission dominates the reverse leakage current in both SJ and HJ, probably related to the structural defects and trap levels in the CZTS interlayer. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis of TiN/a-Si3N4 thin film by using a Mather type dense plasma focus system

NASA Astrophysics Data System (ADS)

Hussain, T.; R., Ahmad; Khalid, N.; A. Umar, Z.; Hussnain, A.

2013-05-01

A 2.3 kJ Mather type pulsed plasma focus device was used for the synthesis of a TiN/a-Si3N4 thin film at room temperature. The film was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The XRD pattern confirms the growth of polycrystalline TiN thin film. The XPS results indicate that the synthesized film is non-stoichiometric and contains titanium nitride, silicon nitride, and a phase of silicon oxy-nitride. The SEM and AFM results reveal that the surface of the synthesized film is quite smooth with 0.59 nm roughness (root-mean-square).

Confirming nasogastric tube placement: Is the colorimeter as sensitive and specific as X-ray? A diagnostic accuracy study.

PubMed

Mordiffi, Siti Zubaidah; Goh, Mien Li; Phua, Jason; Chan, Yiong-Huak

2016-09-01

The effect of delivering enteral nutrition or medications via a nasogastric tube that is inadvertently located in the tracheobronchial tract can cause respiratory complications. Although radiographic examination is accepted as the gold standard for confirming the position of patients' enteral tubes, it is costly, involves risks of radiation, and is not failsafe. Studies using carbon dioxide sensors to detect inadvertent nasogastric tube placements have been conducted in intensive care settings. However, none involved patients in general wards. The objective of this study was to ascertain the diagnostic measure of colorimeter, with radiographic examination as the reference standard, to confirm the location of nasogastric tubes in patients. A prospective observational study of a diagnostic test. This study was conducted in the general wards of an approximately 1100-bed acute care tertiary hospital of an Academic Medical Center in Singapore. Adult patients with nasogastric tubes admitted to the general wards were recruited into the study. The colorimeter was attached to the nasogastric tube to detect for the presence of carbon dioxide, suggestive of a tracheobronchial placement. The exact location of the nasogastric tube was subsequently confirmed by a radiographic examination. A total of 192 tests were undertaken. The colorimeter detected carbon dioxide in 29 tested nasogastric tubes, of which radiographic examination confirmed that four tubes were located in the tracheobronchial tract. The colorimeter failed to detect carbon dioxide in one nasogastric tube that was located in the tracheobronchial tract, thus, demonstrating a sensitivity of 0.80 [95% CI (0.376, 0.964)]. The colorimeter detected absence of carbon dioxide in 163 tested nasogastric tubes in which radiographic examination confirmed 160 gastrointestinal and one tracheobronchial placements, demonstrating a specificity of 0.865 [95% CI (0.808, 0.907)]. The colorimeter detected one tracheobronchial

Lay Evaluation of Financial Experts: The Action Advice Effect and Confirmation Bias.

PubMed

Zaleskiewicz, Tomasz; Gasiorowska, Agata; Stasiuk, Katarzyna; Maksymiuk, Renata; Bar-Tal, Yoram

2016-01-01

The goal of this experimental project was to investigate lay peoples' perceptions of epistemic authority (EA) in the field of finance. EA is defined as the extent to which a source of information is treated as evidence for judgments independently of its objective expertise and based on subjective beliefs. Previous research suggested that EA evaluations are biased and that lay people tend to ascribe higher EA to experts who advise action (in the case of medical experts) or confirm clients' expectations (in the case of politicians). However, there has been no research into biases in lay evaluations of financial experts and this project is aimed to fill this gap. Experiment 1 showed that lay people tended to ascribe greater authority to financial consultants who gave more active advice to clients considering taking out a mortgage. Experiment 2 confirmed the action advice effect found in Experiment 1. However, the outcomes of Experiments 2 and - particularly - 3 suggested that this bias might also be due to clients' desire to confirm their own opinions. Experiment 2 showed that the action advice effect was moderated by clients' own opinions on taking loans. Lay people ascribed the greatest EA to the advisor in the scenario in which he advised taking action and where this coincided with the client's positive opinion on the advisability of taking out a loan. In Experiment 3 only participants with a positive opinion on the financial product ascribed greater authority to experts who recommended it; participants whose opinion was negative tended to rate consultants who advised rejecting the product more highly. To conclude, these three experiments revealed that lay people ascribe higher EA to financial consultants who advise action rather than maintenance of the status quo , but this effect is limited by confirmation bias: when the client's a priori opinion is salient, greater authority is ascribed to experts whose advice confirms it. In this sense, results presented in the

Lay Evaluation of Financial Experts: The Action Advice Effect and Confirmation Bias

PubMed Central

Zaleskiewicz, Tomasz; Gasiorowska, Agata; Stasiuk, Katarzyna; Maksymiuk, Renata; Bar-Tal, Yoram

2016-01-01

The goal of this experimental project was to investigate lay peoples’ perceptions of epistemic authority (EA) in the field of finance. EA is defined as the extent to which a source of information is treated as evidence for judgments independently of its objective expertise and based on subjective beliefs. Previous research suggested that EA evaluations are biased and that lay people tend to ascribe higher EA to experts who advise action (in the case of medical experts) or confirm clients’ expectations (in the case of politicians). However, there has been no research into biases in lay evaluations of financial experts and this project is aimed to fill this gap. Experiment 1 showed that lay people tended to ascribe greater authority to financial consultants who gave more active advice to clients considering taking out a mortgage. Experiment 2 confirmed the action advice effect found in Experiment 1. However, the outcomes of Experiments 2 and – particularly – 3 suggested that this bias might also be due to clients’ desire to confirm their own opinions. Experiment 2 showed that the action advice effect was moderated by clients’ own opinions on taking loans. Lay people ascribed the greatest EA to the advisor in the scenario in which he advised taking action and where this coincided with the client’s positive opinion on the advisability of taking out a loan. In Experiment 3 only participants with a positive opinion on the financial product ascribed greater authority to experts who recommended it; participants whose opinion was negative tended to rate consultants who advised rejecting the product more highly. To conclude, these three experiments revealed that lay people ascribe higher EA to financial consultants who advise action rather than maintenance of the status quo, but this effect is limited by confirmation bias: when the client’s a priori opinion is salient, greater authority is ascribed to experts whose advice confirms it. In this sense, results

Missed opportunities: refusal to confirm reactive rapid HIV tests in the emergency department.

PubMed

Ganguli, Ishani; Collins, Jamie E; Reichmann, William M; Losina, Elena; Katz, Jeffrey N; Arbelaez, Christian; Donnell-Fink, Laurel A; Walensky, Rochelle P

2013-01-01

HIV infection remains a major US public health concern. While HIV-infected individuals now benefit from earlier diagnosis and improved treatment options, progress is tempered by large numbers of newly diagnosed patients who are lost to follow-up prior to disease confirmation and linkage to care. In the randomized, controlled USHER trial, we offered rapid HIV tests to patients presenting to a Boston, MA emergency department. Separate written informed consent was required for confirmatory testing. In a secondary analysis, we compared participants with reactive results who did and did not complete confirmatory testing to identify factors associated with refusal to complete the confirmation protocol. Thirteen of 62 (21.0%, 95% CI (11.7%, 33.2%)) participants with reactive rapid HIV tests refused confirmation; women, younger participants, African Americans, and those with fewer HIV risks, with lower income, and without primary care doctors were more likely to refuse. We projected that up to four true HIV cases were lost at the confirmation stage. These findings underscore the need to better understand the factors associated with refusal to confirm reactive HIV testing and to identify interventions that will facilitate confirmatory testing and linkage to care among these populations. ClinicalTrials.gov NCT00502944; NCT01258582.

Installation Restoration Program. Phase 2. Confirmation/Quantification. Stage 1

DTIC Science & Technology

1986-03-28

Comftin,,,on Fvvem in.eea),a n dftl by bloe * numri ~A Problem Confirmation Study was conducted at Burlington Air National Guard BasE in Vermont. The...cont’d) 3. Characteristics(cont’d)- Biological Agent ( ) Volatile (4f Toxic (). Reactive ( ) 4. Toxicity: TLVs IDLHs 5. Special Hazards 6. Acute

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Laura; Harvey, Stephen P.; Teeter, Glenn

We demonstrate the potential of X-ray photoelectron spectroscopy (XPS) to characterize new carrier-selective contacts (CSC) for solar cell application. We show that XPS not only provides information about the surface chemical properties of the CSC material, but that operando XPS, i.e. under light bias condition, can also directly measure the photovoltage that develops at the CSC/absorber interface, revealing device relevant information without the need of assembling a full solar cell. We present the application of the technique to molybdenum oxide hole-selective contact films on a crystalline silicon absorber.

First confirmation of Pseudogymnoascus destructans in British bats and hibernacula.

PubMed

Barlow, A M; Worledge, L; Miller, H; Drees, K P; Wright, P; Foster, J T; Sobek, C; Borman, A M; Fraser, M

2015-07-18

White-nose syndrome (WNS) is a fatal fungal infection of bats in North America caused by Pseudogymnoascus destructans. P. destructans has been confirmed in Continental Europe but not associated with mass mortality. Its presence in Great Britain was unknown. Opportunistic sampling of bats in GB began during the winter of 2009. Any dead bats or samples from live bats with visible fungal growths were submitted to the Animal Health and Veterinary Laboratories Agency for culture. Active surveillance by targeted environmental sampling of hibernacula was carried out during the winter of 2012/2013. Six hibernacula were selected by their proximity to Continental Europe. Five samples, a combination of surface swabs or sediment samples, were collected. These were sent to the Center for Microbial Genetics and Genomics, Northern Arizona University, for P. destructans PCR. Forty-eight incidents were investigated between March 2009 and July 2013. They consisted of 46 bat carcases and 31 other samples. A suspected P. destructans isolate was cultured from a live Daubenton's bat (Myotis daubentonii) sampled in February 2013. This isolate was confirmed by the Mycology Reference Laboratory, Bristol (Public Health England), as P. destructans. A variety of fungi were isolated from the rest but all were considered to be saprophytic or incidental. P. destructans was also confirmed by the Center for Microbial Genetics and Genomics in five of the six sites surveyed. British Veterinary Association.

Modeling confirmation bias and polarization

NASA Astrophysics Data System (ADS)

Del Vicario, Michela; Scala, Antonio; Caldarelli, Guido; Stanley, H. Eugene; Quattrociocchi, Walter

2017-01-01

Online users tend to select claims that adhere to their system of beliefs and to ignore dissenting information. Confirmation bias, indeed, plays a pivotal role in viral phenomena. Furthermore, the wide availability of content on the web fosters the aggregation of likeminded people where debates tend to enforce group polarization. Such a configuration might alter the public debate and thus the formation of the public opinion. In this paper we provide a mathematical model to study online social debates and the related polarization dynamics. We assume the basic updating rule of the Bounded Confidence Model (BCM) and we develop two variations a) the Rewire with Bounded Confidence Model (RBCM), in which discordant links are broken until convergence is reached; and b) the Unbounded Confidence Model, under which the interaction among discordant pairs of users is allowed even with a negative feedback, either with the rewiring step (RUCM) or without it (UCM). From numerical simulations we find that the new models (UCM and RUCM), unlike the BCM, are able to explain the coexistence of two stable final opinions, often observed in reality. Lastly, we present a mean field approximation of the newly introduced models.

Drilling confirms hot-spot origins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-02-01

Eleven holes were drilled at 4 sites in the Emperor Seamount chain in order to test the hot-spot hypothesis of the origin of the Hawaiian and Emperor chains and several important corollaries. Basalt was penetrated at 3 sites, and the paleontological ages of the lowest sediments above basalt are consistent with a linear geochron connecting the ages of Meiji Seamount to the north, and Koko and Yuryaku seamounts to the south. The chemical composition of the upper 4 basalt flow units cored at Ojin Seamount indicates that they are typical Hawaiites. A sample of tholeiite was recovered from the bottommore » of the hole. The lava flows from Ojin, Nintoku, and Suiko have natural remanent magnetization that is relatively stable to alternating field demagnetization, as expected of oceanic-island basalts. Many of the basalts at all 3 sites have highly vesicular and oxidized flow tops and bottoms. Observations indicate that the flows were erupted subaerially, and that Ojin, Nintoku, and Suiko volcanoes once stood well above sea level. In a general way, the hot-spot origin of the Emperor Seamount chain was confirmed. (JGB)« less

Confirming Glycemic Status in the Diabetes Prevention Program: Implications for Diagnosing Diabetes in High Risk Adults

PubMed Central

Christophi, C. A.; Resnick, H. E.; Ratner, R. E.; Temprosa, M.; Fowler, S.; Knowler, W. C.; Shamoon, H.; Barrett-Connor, E.; Kahn, S. E.

2012-01-01

Aims To examine the ability of FPG and/or 2-hr glucose to confirm diabetes and to determine the proportion of participants with HbA1c ≥6.5%. Methods Diabetes confirmation rates were calculated after a single elevated FPG and/or 2-hr glucose on an oral glucose tolerance test (OGTT) using a confirmatory OGTT performed within 6 weeks. Results 772 (24%) participants had elevated FPG or 2-hr glucose on an OGTT that triggered a confirmation visit. There were 101 triggers on FPG alone, 574 on 2-hr glucose alone, and 97 on both. Only 47% of participants who triggered had confirmed diabetes. While the confirmation rate for FPG was higher than that for 2-hr glucose, the larger number of 2-hr glucose triggers resulted in 87% of confirmed cases triggering on 2-hr glucose. Confirmation rates increased to 75% among persons with FPG ≥126 mg/dl and HbA1c ≥6.5%. Conclusions Only half of persons with elevated FPG and IGT were subsequently confirmed to have diabetes. At current diagnostic levels, more persons trigger on 2-hr glucose than on FPG, but fewer of these persons have their diagnoses confirmed. In individuals with FPG ≥126 mg/dl and HbA1c ≥6.5%, the confirmation rate was increased. PMID:23140912

Confirming glycemic status in the Diabetes Prevention Program: implications for diagnosing diabetes in high risk adults.

PubMed

Christophi, C A; Resnick, H E; Ratner, R E; Temprosa, M; Fowler, S; Knowler, W C; Shamoon, H; Barrett-Connor, E; Kahn, S E

2013-01-01

To examine the ability of fasting plasma glucose (FPG) and/or 2-h glucose to confirm diabetes and to determine the proportion of participants with HbA1c ≥6.5%. Diabetes confirmation rates were calculated after a single elevated FPG and/or 2-h glucose on an oral glucose tolerance test (OGTT) using a confirmatory OGTT performed within 6 weeks. 772 (24%) participants had elevated FPG or 2-h glucose on an OGTT that triggered a confirmation visit. There were 101 triggers on FPG alone, 574 on 2-h glucose alone, and 97 on both. Only 47% of participants who triggered had confirmed diabetes. While the confirmation rate for FPG was higher than that for 2-h glucose, the larger number of 2-h glucose triggers resulted in 87% of confirmed cases triggering on 2-h glucose. Confirmation rates increased to 75% among persons with FPG ≥126 mg/dl and HbA1c ≥6.5%. Only half of the persons with elevated FPG and IGT were subsequently confirmed to have diabetes. At current diagnostic levels, more persons trigger on 2-h glucose than on FPG, but fewer of these persons have their diagnoses confirmed. In individuals with FPG ≥126 mg/dl and HbA1c ≥6.5%, the confirmation rate was increased. Copyright © 2013 Elsevier Inc. All rights reserved.

Terra Data Confirm Warm, Dry U.S. Winter

NASA Technical Reports Server (NTRS)

2002-01-01

New maps of land surface temperature and snow cover produced by NASA's Terra satellite show this year's winter was warmer than last year's, and the snow line stayed farther north than normal. The observations confirm earlier National Oceanic and Atmospheric Administration reports that the United States was unusually warm and dry this past winter. (Click to read the NASA press release and to access higher-resolution images.) For the last two years, a new sensor aboard Terra has been collecting the most detailed global measurements ever made of our world's land surface temperatures and snow cover. The Moderate-resolution Imaging Spectroradiometer (MODIS) is already giving scientists new insights into our changing planet. Average temperatures during December 2001 through February 2002 for the contiguous United States appear to have been unseasonably warm from the Rockies eastward. In the top image the coldest temperatures appear black, while dark green, blue, red, yellow, and white indicate progressively warmer temperatures. MODIS observes both land surface temperature and emissivity, which indicates how efficiently a surface absorbs and emits thermal radiation. Compared to the winter of 2000-01, temperatures throughout much of the U.S. were warmer in 2001-02. The bottom image depicts the differences on a scale from dark blue (colder this year than last) to red (warmer this year than last). A large region of warm temperatures dominated the northern Great Plains, while the area around the Great Salt Lake was a cold spot. Images courtesy Robert Simmon, NASA GSFC, based upon data courtesy Zhengming Wan, MODIS Land Science Team member at the University of California, Santa Barbara's Institute for Computational Earth System Science

Growth of transparent Zn1 - xSrxO (0.0 ≤ x ≤ 0.08) films by facile wet chemical method: Effect of Sr doping on the structural, optical and sensing properties

NASA Astrophysics Data System (ADS)

Rana, Amit Kumar; Das, Rajasree; Kumar, Yogendra; Sen, Somaditya; Shirage, Parasharam M.

2016-08-01

Zn1 - xSrxO (0.0 ≤ x ≤ 0.08) nano-rods thin films are prepared using simple wet chemical technique on transparent flexible substrate. Effect of Sr-doping on structural and optical properties of ZnO is systematically investigated. SEM and TEM confirm the nano-rods like morphology with single crystalline nature of all the samples. Rietveld refinement of XRD shows the samples belongs to P63mc space group, furthermore, a gradual increment in lattice parameters and change in Zn/oxygen occupancy ratio is observed with Sr doping. SIMS and XPS confirm the doping of Sr in the ZnO nanostructures. XPS measurements shows that increase in Sr doping creates more oxygen associated defects, which is further supported by the photoluminescence spectra indicating the gradual change in Zn vacancy (Vzn) and oxygen interstitial (Oin) point defect intensities in the films. Near band edge emission peak shows to shift toward higher wavelength in the doped films. Pure ZnO film shows Raman peaks around 99 (E2low), 333 (E2high - E2low) , 382 (A1 (TO)), 438 (E2high) and 582 (A1 (LO) +E1 (TO)) cm-1, whereas two additional defect driven vibrational modes (at 277 and 663 cm-1) are appeared in the Sr-doped films. The sensing property of the ZnO is enhanced by Sr doping and replicates as a promising material for future toxic and flammable gas sensor applications as well as for opto-electronic devices.

Quality of Life among Adults with Confirmed Dengue in Brazil

PubMed Central

Martelli, Celina Maria Turchi; Nascimento, Nazareth Elias; Suaya, Jose A.; Siqueira, Joao Bosco; Souza, Wayner Vieira; Turchi, Marilia Dalva; Guilarde, Adriana Oliveira; Peres, Joao Borges; Shepard, Donald S.

2011-01-01

The main objective of this study was to measure the quality of life (QoL) during a dengue episode. We conducted a facility-based survey in central Brazil in 2005 and recruited 372 laboratory-confirmed dengue patients greater than 12 years of age in hospital and ambulatory settings. We administered the World Health Organization QoL instrument approximately 15 days after the onset of symptoms. We used principal component analysis with varimax rotation to identify domains related to QoL. The median age of interviewees was 36 years. Most (85%) reported their general health status as very good or good before the dengue episode. Although ambulatory patients were mainly classified as having dengue fever, 44.8% of hospitalized patients had dengue hemorrhagic fever or intermediate dengue. Principal component analysis identified five principal components related to cognition, sleep and energy, mobility, self-care, pain, and discomfort, which explained 73% of the variability of the data matrix. Hospitalized patients had significantly lower mean scores for dimensions cognition, self-care, and pain than ambulatory patients. This investigation documented the generally poor QoL during a dengue episode caused by the large number of domains affected and significant differences between health care settings. PMID:21976580

Accuracy of Intravenous Electrocardiography Confirmation of Peripherally Inserted Central Catheter for Parenteral Nutrition.

PubMed

Mundi, Manpreet S; Edakkanambeth Varayil, Jithinraj; McMahon, Megan T; Okano, Akiko; Vallumsetla, Nishanth; Bonnes, Sara L; Andrews, James C; Hurt, Ryan T

2016-04-01

Parenteral nutrition (PN) is a life-saving therapy for patients with intestinal failure. Safe delivery of hyperosmotic solution requires a central venous catheter (CVC) with tip in the lower superior vena cava (SVC) or at the SVC-right atrium (RA) junction. To reduce cost and delay in use of CVC, new techniques such as intravascular electrocardiogram (ECG) are being used for tip confirmation in place of chest x-ray (CXR). The present study assessed for accuracy of ECG confirmation in home PN (HPN). Records for all patients consulted for HPN from December 17, 2014, to June 16, 2015, were reviewed for patient demographics, diagnosis leading to HPN initiation, and ECG and CXR confirmation. CXRs were subsequently reviewed by a radiologist to reassess location of the CVC tip and identify those that should be adjusted. Seventy-three patients were eligible, and after assessment for research authorization and postplacement CXR, 17 patients (30% male) with an age of 54 ± 14 years were reviewed. In all patients, postplacement intravascular ECG reading stated tip in the SVC. However, based on CXR, the location of the catheter tip was satisfactory (low SVC or SVC-RA junction) in 10 of 17 patients (59%). Due to the high osmolality of PN, CVC tip location is of paramount importance. After radiology review of CXR, we noted that 7 of 17 (41%) peripherally inserted central catheter lines were in an unsatisfactory position despite ECG confirmation. With current data available, intravenous ECG confirmation should not be used as the sole source of tip confirmation in patients receiving HPN. © 2016 American Society for Parenteral and Enteral Nutrition.

Passivation of InGaAs(001)-(2 × 4) by Self-Limiting Chemical Vapor Deposition of a Silicon Hydride Control Layer.

PubMed

Edmonds, Mary; Kent, Tyler; Chagarov, Evgueni; Sardashti, Kasra; Droopad, Ravi; Chang, Mei; Kachian, Jessica; Park, Jun Hong; Kummel, Andrew

2015-07-08

A saturated Si-Hx seed layer for gate oxide or contact conductor ALD has been deposited via two separate self-limiting and saturating CVD processes on InGaAs(001)-(2 × 4) at substrate temperatures of 250 and 350 °C. For the first self-limiting process, a single silicon precursor, Si3H8, was dosed at a substrate temperature of 250 °C, and XPS results show the deposited silicon hydride layer saturated at about 4 monolayers of silicon coverage with hydrogen termination. STS results show the surface Fermi level remains unpinned following the deposition of the saturated silicon hydride layer, indicating the InGaAs surface dangling bonds are electrically passivated by Si-Hx. For the second self-limiting process, Si2Cl6 was dosed at a substrate temperature of 350 °C, and XPS results show the deposited silicon chloride layer saturated at about 2.5 monolayers of silicon coverage with chlorine termination. Atomic hydrogen produced by a thermal gas cracker was subsequently dosed at 350 °C to remove the Si-Cl termination by replacing with Si-H termination as confirmed by XPS, and STS results confirm the saturated Si-Hx bilayer leaves the InGaAs(001)-(2 × 4) surface Fermi level unpinned. Density function theory modeling of silicon hydride surface passivation shows an Si-Hx monolayer can remove all the dangling bonds and leave a charge balanced surface on InGaAs.

A factor confirmation and convergent validity of the “areas of worklife scale” (AWS) to Spanish translation

PubMed Central

2013-01-01

Background Perceived incongruity between the individual and the job on work-life areas such as workload, control, reward, fairness, community and values have implications for the dimensions of burnout syndrome. The “Areas of Work-life Scale” (AWS) is a practical instrument to measure employees´ perceptions of their work environments. AIMS: Validate a Spanish translation of the AWS, and it relationship with Masclach Burnout Inventory dimensions. Methods The study was conducted in three medium-sized hospitals and seven rural and urban Primary Care centres (N = 871) in Spain. The “Maslach Burnout Inventory General Survey” (MBI-GS) and AWS were applied. We developed a complete psychometric analysis of its reliability, and validity. Results Data on the reliability supported a good internal consistency (Cronbach α between .71, and .85). Construct validity was confirmed by a six factor model of the AWS as a good measure of work environments (χ2(352) = 806.21, p < 0.001; χ2/df = 2.29; CFI = 0.935, RMSEA = 0.039); concurrent validity was analysed for its relationship with other measures (opposing dimensions to burnout, and MBI), and each correlation between dimensions and sub-dimensions were statistically significant; as well, predictive validity, by a series of Multiple Regression Analysis examined the resulting patterns of the Confirmatory Factor Analysis (CFA) confirms the relationship between the work-life areas and burnout dimensions. Conclusions Leiter and Maslach’s AWS has been an important instrument in exploring several work-life factors that contribute to burnout. This scale can now be used to assess the quality of work-life in order to design and assess the need for intervention programs in Spanish-speaking countries. PMID:23596987

Departure gate of acidic Ca2+ confirmed

PubMed Central

Jentsch, Thomas J; Hoegg-Beiler, Maja B; Vogt, Janis

2015-01-01

More potent, but less known than IP3 that liberates Ca2+ from the ER, NAADP releases Ca2+ from acidic stores. The notion that TPC channels mediate this Ca2+ release was questioned recently by studies suggesting that TPCs are rather PI(3,5)P2-activated Na+ channels. Ruas et al (2015) now partially reconcile these views by showing that TPCs significantly conduct both cations and confirm their activation by both NAADP and PI(3,5)P2. They attribute the failure of others to observe TPC-dependent NAADP-induced Ca2+ release in vivo to inadequate mouse models that retain partial TPC function. PMID:26022292

Forensic Drug Identification, Confirmation, and Quantification Using Fully Integrated Gas Chromatography with Fourier Transform Infrared and Mass Spectrometric Detection (GC-FT-IR-MS).

PubMed

Lanzarotta, Adam; Lorenz, Lisa; Voelker, Sarah; Falconer, Travis M; Batson, JaCinta S

2018-05-01

This manuscript is a continuation of a recent study that described the use of fully integrated gas chromatography with direct deposition Fourier transform infrared detection and mass spectrometric detection (GC-FT-IR-MS) to identify and confirm the presence of sibutramine and AB-FUBINACA. The purpose of the current study was to employ the GC-FT-IR portion of the same instrument to quantify these compounds, thereby demonstrating the ability to identify, confirm, and quantify drug substances using a single GC-FT-IR-MS unit. The performance of the instrument was evaluated by comparing quantitative analytical figures of merit to those measured using an established, widely employed method for quantifying drug substances, high performance liquid chromatography with ultraviolet detection (HPLC-UV). The results demonstrated that GC-FT-IR was outperformed by HPLC-UV with regard to sensitivity, precision, and linear dynamic range (LDR). However, sibutramine and AB-FUBINACA concentrations measured using GC-FT-IR were not significantly different at the 95% confidence interval compared to those measured using HPLC-UV, which demonstrates promise for using GC-FT-IR as a semi-quantitative tool at the very least. The most significant advantage of GC-FT-IR compared to HPLC-UV is selectivity; a higher level of confidence regarding the identity of the analyte being quantified is achieved using GC-FT-IR. Additional advantages of using a single GC-FT-IR-MS instrument for identification, confirmation, and quantification are efficiency, increased sample throughput, decreased consumption of laboratory resources (solvents, chemicals, consumables, etc.), and thus cost.

Audiometric analyses confirm a cochlear component, disproportional to age, in stapedial otosclerosis.

PubMed

Topsakal, Vedat; Fransen, Erik; Schmerber, Sébastien; Declau, Frank; Yung, Matthew; Gordts, Frans; Van Camp, Guy; Van de Heyning, Paul

2006-09-01

To report the preoperative audiometric profile of surgically confirmed otosclerosis. Retrospective, multicenter study. Four tertiary referral centers. One thousand sixty-four surgically confirmed patients with otosclerosis. Therapeutic ear surgery for hearing improvement. Preoperative audiometric air conduction (AC) and bone conduction (BC) hearing thresholds were obtained retrospectively for 1064 patients with otosclerosis. A cross-sectional multiple linear regression analysis was performed on audiometric data of affected ears. Influences of age and sex were analyzed and age-related typical audiograms were created. Bone conduction thresholds were corrected for Carhart effect and presbyacusis; in addition, we tested to see if separate cochlear otosclerosis component existed. Corrected thresholds were than analyzed separately for progression of cochlear otosclerosis. The study population consisted of 35% men and 65% women (mean age, 44 yr). The mean pure-tone average at 0.5, 1, and 2 kHz was 57 dB hearing level. Multiple linear regression analysis showed significant progression for all measured AC and BC thresholds. The average annual threshold deterioration for AC was 0.45 dB/yr and the annual threshold deterioration for BC was 0.37 dB/yr. The average annual gap expansion was 0.08 dB/year. The corrected BC thresholds for Carhart effect and presbyacusis remained significantly different from zero, but only showed progression at 2 kHz. The preoperative audiological profile of otosclerosis is described. There is a significant sensorineural component in patients with otosclerosis planned for stapedotomy, which is worse than age-related hearing loss by itself. Deterioration rates of AC and BC thresholds have been reported, which can be helpful in clinical practice and might also guide the characterization of allegedly different phenotypes for familial and sporadic otosclerosis.

Spectroscopic Confirmation of Five Galaxy Clusters at z > 1.25 in the 2500 deg^2 SPT-SZ Survey

NASA Astrophysics Data System (ADS)

Khullar, Gourav; Bleem, Lindsey; Bayliss, Matthew; Gladders, Michael; South Pole Telescope (SPT) Collaboration

2018-06-01

We present spectroscopic confirmation of 5 galaxy clusters at 1.25 < z < 1.5, discovered in the 2500 deg2 South Pole Telescope Sunyaev-Zel’dovich (SPT-SZ) survey. These clusters, taken from a nearly redshift-independent mass-limited sample of clusters, have multi-wavelength follow-up imaging data from the X-ray to the near-IR, and currently form the most homogenous massive high-redshift cluster sample in existence. We briefly describe the analysis pipeline used on the low S/N spectra of these faint galaxies, and describing the multiple techniques used to extract robust redshifts from a combination of absorption-line (Ca II H&K doublet - λλ3934,3968Å) and emission-line ([OII] λλ3727,3729Å) spectral features. We present several ensemble analyses of cluster member galaxies that demonstrate the reliability of the measured redshifts. We also identify modest [OII] emission and pronounced CN and Hδ absorption in a composite stacked spectrum of 28 low S/N passive galaxy spectra with redshifts derived primarily from Ca II H&K features. This work increases the number of spectroscopically-confirmed SPT-SZ galaxy clusters at z > 1.25 from 2 to 7, further demonstrating the efficacy of SZ selection for the highest redshift massive clusters, and enabling further detailed study of these confirmed systems.

Visual Confirmation (VICON) of Takeoff Clearance Signal System Impact Study

DOT National Transportation Integrated Search

1980-11-01

A study was performed to evaluate the impact on airport capacity and voice communications of the Visual Confirmation of Takeoff Clearance (VICON) Signal System. Befoe-and-after test data collection and analysis were conducted at Bradley International...

Infection by Streptococcus pneumoniae in children with or without radiologically confirmed pneumonia.

PubMed

Andrade, Dafne C; Borges, Igor C; Vilas-Boas, Ana Luísa; Fontoura, Maria S H; Araújo-Neto, César A; Andrade, Sandra C; Brim, Rosa V; Meinke, Andreas; Barral, Aldina; Ruuskanen, Olli; Käyhty, Helena; Nascimento-Carvalho, Cristiana M

Community-acquired pneumonia is an important cause of morbidity in childhood, but the detection of its causative agent remains a diagnostic challenge. The authors aimed to evaluate the role of the chest radiograph to identify cases of community-aquired pneumonia caused by typical bacteria. The frequency of infection by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis was compared in non-hospitalized children with clinical diagnosis of community acquired pneumonia aged 2-59 months with or without radiological confirmation (n=249 and 366, respectively). Infection by S. pneumoniae was diagnosed by the detection of a serological response against at least one of eight pneumococcal proteins (defined as an increase ≥2-fold in the IgG levels against Ply, CbpA, PspA1 and PspA2, PhtD, StkP-C, and PcsB-N, or an increase ≥1.5-fold against PcpA). Infection by H. influenzae and M. catarrhalis was defined as an increase ≥2-fold on the levels of microbe-specific IgG. Children with radiologically confirmed pneumonia had higher rates of infection by S. pneumoniae. The presence of pneumococcal infection increased the odds of having radiologically confirmed pneumonia by 2.8 times (95% CI: 1.8-4.3). The negative predictive value of the normal chest radiograph for infection by S. pneumoniae was 86.3% (95% CI: 82.4-89.7%). There was no difference on the rates of infection by H. influenzae and M. catarrhalis between children with community-acquired pneumonia with and without radiological confirmation. Among children with clinical diagnosis of community-acquired pneumonia submitted to chest radiograph, those with radiologically confirmed pneumonia present a higher rate of infection by S. pneumoniae when compared with those with a normal chest radiograph. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Optimization of Regression Models of Experimental Data Using Confirmation Points

NASA Technical Reports Server (NTRS)

Ulbrich, N.

2010-01-01

A new search metric is discussed that may be used to better assess the predictive capability of different math term combinations during the optimization of a regression model of experimental data. The new search metric can be determined for each tested math term combination if the given experimental data set is split into two subsets. The first subset consists of data points that are only used to determine the coefficients of the regression model. The second subset consists of confirmation points that are exclusively used to test the regression model. The new search metric value is assigned after comparing two values that describe the quality of the fit of each subset. The first value is the standard deviation of the PRESS residuals of the data points. The second value is the standard deviation of the response residuals of the confirmation points. The greater of the two values is used as the new search metric value. This choice guarantees that both standard deviations are always less or equal to the value that is used during the optimization. Experimental data from the calibration of a wind tunnel strain-gage balance is used to illustrate the application of the new search metric. The new search metric ultimately generates an optimized regression model that was already tested at regression model independent confirmation points before it is ever used to predict an unknown response from a set of regressors.

(001) 3C SiC/Ni contact interface: In situ XPS observation of annealing induced Ni2Si formation and the resulting barrier height changes

NASA Astrophysics Data System (ADS)

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

2017-04-01

The electronic states of the (001) 3C SiC/Ni interface prior and post annealing are investigated via an in situ XPS interface experiment, allowing direct observation of the induced band bending and the transformation from Schottky to ohmic behaviour for the first time. A single domain (001) 3C SiC sample was prepared via wet chemical etching. Nickel was deposited on the sample in multiple in situ deposition steps via RF sputtering, allowing observation of the 3C SiC/Ni interface formation. Over the course of the experiments, an upward band bending of 0.35 eV was observed, along with defect induced Fermi level pinning. This indicates a Schottky type contact behaviour with a barrier height of 0.41 eV. The subsequent annealing at 850 °C for 5 min resulted in the formation of a Ni2Si layer and a reversal of the band bending to 0.06 eV downward. Thus explaining the ohmic contact behaviour frequently reported for annealed n-type 3C SiC/Ni contacts.

Polyethylene imine modified hydrochar adsorption for chromium (VI) and nickel (II) removal from aqueous solution.

PubMed

Shi, Yuanji; Zhang, Tao; Ren, Hongqiang; Kruse, Andrea; Cui, Ruofan

2018-01-01

An adsorbent hydrochar was synthesized from corn cobs and modified with polyethylene imine (PEI). The hydrochars before and after modification were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis. FTIR and XPS revealed that the PEI was grafted onto the hydrochar via ether and imine bonds formed with glutaraldehyde. The maximum adsorption capacities for Cr(VI) (33.663mg/g) and Ni(II) (29.059mg/g) on the modified hydrochars were 365% and 43.7% higher, respectively, than those on the unmodified hydrochar. A pseudo-second-order model described the adsorption of Ni(II) and Cr(VI) on all the adsorbents. The adsorption of Cr(VI) was endothermic, spontaneous, increased disorder, and obeyed the Langmuir model. By contrast, the adsorption of Ni(II) was exothermic, spontaneous, decreased disorder, and obeyed the Freundlich model. XPS confirmed that the adsorption sites and mechanisms for Ni(II) and Cr(VI) on the modified hydrochars were different. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deposition and characterization of stoichiometric films of V2O5 on Pd(111)

NASA Astrophysics Data System (ADS)

Feng, Xu; Abdel-Rahman, Mohammed K.; Kruppe, Christopher M.; Trenary, Michael

2017-10-01

A simple and efficient method has been used to grow V2O5 thin films on Pd(111) at a substrate temperature of 300 K through physical vapor deposition by heating a fine powder of V2O5 in a non-oxidative, UHV environment. X-ray photoelectron spectroscopy (XPS), reflection absorption infrared spectroscopy (RAIRS) and low energy electron diffraction (LEED) were used to characterize the thin films. When the as-grown films exceed a minimum thickness, characteristic features of V2O5 were revealed by XPS and RAIRS, which confirms the presence of stoichiometric V2O5. LEED indicates no long range order of the as-grown films at 300 K. Annealing to temperatures between 600 and 700 K causes a reduction of V2O5 to VO2 as identified by XPS and the formation of ordered structures as determined by LEED, and VO2 is predominant after annealing to 800 K. After further annealing to 1000 K, only an ordered form of V2O3 is present on Pd(111).

UV irradiation study of a tripeptide isolated in an argon matrix: A tautomerism process evidenced by infrared and X-ray photoemission spectroscopies

NASA Astrophysics Data System (ADS)

Mateo-Marti, E.; Pradier, C. M.

2013-05-01

Matrix isolation is a powerful tool for studying photochemical processes occurring in isolated molecules. In this way, we characterized the chemical modifications occurring within a tri peptide molecule, IGF, when exposed to the influence of Ultraviolet (UV) irradiation. This paper first describes the successful formation of the tripeptide (IGF) argon matrix under vacuum conditions, followed by the in situ UV irradiation and characterization of the molecular matrix reactivity after UV-irradiation. These studies have been performed by combining two complementary spectroscopic techniques, Fourier-Transform Reflexion Absorption Spectroscopy (FT-IRRAS) and X-ray Photoelectron Spectroscopy (XPS). The IR spectra of the isolated peptide-matrix, before and after UV irradiation, revealed significant differences that could be associated either to a partial deprotonation of the molecule or to a tautomeric conversion of some amide bonds to imide ones on some peptide molecules. XPS analyses undoubtedly confirmed the second hypothesis; the combination of IRRAS and XPS results provide evidence that UV irradiation of peptides induces a chemical reaction, namely a shift of the double bond, meaning partial conversion from amide tautomer into an imidic acid tautomer.

Atomic layer deposition of ruthenium surface-coating on porous platinum catalysts for high-performance direct ethanol solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Jeong, Heon Jae; Kim, Jun Woo; Jang, Dong Young; Shim, Joon Hyung

2015-09-01

Pt-Ru bi-metallic catalysts are synthesized by atomic layer deposition (ALD) of Ru surface-coating on sputtered Pt mesh. The catalysts are evaluated in direct ethanol solid oxide fuel cells (DESOFCs) in the temperature range of 300-500 °C. Island-growth of the ALD Ru coating is confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy (XPS) analyses. The performance of the DESOFCs is evaluated based on the current-voltage output and electrochemical impedance spectroscopy. Genuine reduction of the polarization impedance, and enhanced power output with improved surface kinetics are achieved with the optimized ALD Ru surface-coating compared to bare Pt. The chemical composition of the Pt/ALD Ru electrode surface after fuel cell operation is analyzed via XPS. Enhanced cell performance is clearly achieved, attributed to the effective Pt/ALD Ru bi-metallic catalysis, including oxidation of Cdbnd O by Ru, and de-protonation of ethanol and cleavage of C-C bonds by Pt, as supported by surface morphology analysis which confirms formation of a large amount of carbon on bare Pt after the ethanol-fuel-cell test.

Pathological confirmation of nerve-sparing types performed during robot-assisted radical prostatectomy (RARP).

PubMed

Ko, Woo Jin; Hruby, Gregory W; Turk, Andrew T; Landman, Jaime; Badani, Ketan K

2013-03-01

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Incremental nerve-sparing techniques (NSTs) improve postoperative erectile function after robot-assisted radical prostatectomy (RARP). However, there are no studies to date that histologically confirm the surgeon intended NST. Thus, in the present study, we histologically confirmed that the surgeon performed the nerve preservation as his intended NSTs during RARP. Also, we found that there was more variability in fascia width outcome on the left side compared with the right. Therefore, when performing nerve preservation on the surgeon's non-dominant side, we need to pay more close attention. To confirm that the surgeon achieved true intended histological nerve sparing during robot-assisted radical prostatectomy (RARP) by studying RP specimens. To aid the novice robotic surgeon to develop the skills of RARP. Between June 2008 and May 2009, 122 consecutive patients underwent RARP by a single surgeon (K.K.B.). The degree of nerve sparing (wide resection [WR], interfascial nerve sparing [ITE-NS], intrafascial nerve sparing [ITR-NS]) on both sides was recorded. The posterior sectors of RP specimens from distal, mid, and proximal parts were evaluated. Fascia width (FW) of each position in RP specimens were compared across nerve-sparing types (NSTs). FW was recorded at 15 ° intervals (3-9 o'clock position), measured as the distance between the outermost prostate gland and surgical margin. The slides were reviewed by an experienced uropathologist who was 'blinded' to the NST. In all, 93 men were included. The overall mean (sd) FW was the greatest in the order of WR, ITE-NS, and ITR-NS, at 2.42 (1.62), 1.71 (1.40) and 1.16 (1.08) mm, respectively (P < 0.001). FW was statistically significantly correlated with the surgical technique used. When the surgeon intended to perform various levels of nerve sparing, these were reflected in the FW. Interestingly, the left-side FW showed more variability than the

Synthesis and characterization of (3-Aminopropyl)trimethoxy-silane (APTMS) functionalized Gd2O3:Eu(3+) red phosphor with enhanced quantum yield.

PubMed

Jain, Akhil; Hirata, G A; Farías, M H; Castillón, F F

2016-02-12

We report the surface modification of nanocrystalline Gd2O3:Eu(3+) phosphor by (3-Aminopropyl)trimethoxysilane (APTMS). The nanoparticles were first coated with silica using the Stöber process, and then annealed at 650 °C for 2 h. Afterwards, APTMS was functionalized onto the silica layer to obtain Gd2O3:Eu(3+) nanoparticles bearing amine groups on the surface. The effect of silica coating, and the subsequent annealing process on the crystallization of the nanophosphor were analyzed by x-ray diffraction (XRD). High-resolution transmission electron microscopy (HR-TEM) confirmed the presence of a silica layer of ∼45 nm thickness. X-ray photoelectron (XPS) and Fourier transform infrared (FTIR) spectroscopy confirmed the presence of silica and the amine groups. Photoluminescence (PL) analysis demonstrated an increased emission after functionalization of nanoparticles. Absolute quantum yield (QY) measurements revealed an 18% enhancement in QY in functionalized nanoparticles compared with unmodified nanoparticles, which is of great importance for their biomedical applications.

Synthesis and characterization of (3-Aminopropyl)trimethoxy-silane (APTMS) functionalized Gd2O3:Eu3+ red phosphor with enhanced quantum yield

NASA Astrophysics Data System (ADS)

Jain, Akhil; Hirata, G. A.; Farías, M. H.; Castillón, F. F.

2016-02-01

We report the surface modification of nanocrystalline Gd2O3:Eu3+ phosphor by (3-Aminopropyl)trimethoxysilane (APTMS). The nanoparticles were first coated with silica using the Stöber process, and then annealed at 650 °C for 2 h. Afterwards, APTMS was functionalized onto the silica layer to obtain Gd2O3:Eu3+ nanoparticles bearing amine groups on the surface. The effect of silica coating, and the subsequent annealing process on the crystallization of the nanophosphor were analyzed by x-ray diffraction (XRD). High-resolution transmission electron microscopy (HR-TEM) confirmed the presence of a silica layer of ∼45 nm thickness. X-ray photoelectron (XPS) and Fourier transform infrared (FTIR) spectroscopy confirmed the presence of silica and the amine groups. Photoluminescence (PL) analysis demonstrated an increased emission after functionalization of nanoparticles. Absolute quantum yield (QY) measurements revealed an 18% enhancement in QY in functionalized nanoparticles compared with unmodified nanoparticles, which is of great importance for their biomedical applications.

Dielectric relaxation and electronic structure of double perovskite Sr{sub 2}FeSbO{sub 6}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dutta, Alo; Sinha, T. P.; Shannigrahi, Santiranjan

2008-09-15

The dielectric property and the electronic structure of a double perovskite, Sr{sub 2}FeSbO{sub 6} (SFS) synthesized by solid state reaction technique are investigated. The x-ray diffraction of the sample taken at room temperature shows cubic phase. The scanning electron micrograph of the sample also confirms the formation of the single phase of the material. We have measured the capacitance and conductance of SFS in a frequency range from 50 Hz to 1 MHz and in a temperature range from 163 to 463 K. A relaxation is observed in the entire temperature range as a gradual decrease in {epsilon}{sup '}({omega}) andmore » as a broad peak in {epsilon}{sup ''}({omega}). The frequency dependent electrical data are analyzed in the framework of conductivity and electric modulus formalisms. The frequencies corresponding to the maxima of the imaginary electric modulus at various temperatures are found to obey an Arrhenius law with an activation energy of 0.74 eV. The Cole-Cole model is used to study the dielectric relaxation of SFS. The scaling behavior of imaginary part of electric modulus suggests that the relaxation describes the same mechanism at various temperatures. The frequency dependent conductivity spectra follow the universal power law. The electronic structure of the SFS is studied by x-ray photoemission spectroscopy (XPS). Its valence band consists mainly of the oxygen 2p-states hybridized with the Fe 3d-states. The XPS spectra are investigated by the first principles full potential linearized augmented plane wave method. The angular momentum projected total and partial density of states obtained from first principles calculation are used to analyze the XPS results of the sample. The calculated electronic structures of SFS are qualitatively similar to those of the XPS spectra in terms of spectral features, energy positions, and relative intensities. The electronic structure calculation reveals that the electrical properties of SFS are dominated by the interaction

Using the National Assessment of Educational Progress To Confirm State Test Results. A Report of the Ad Hoc Committee on Confirming Test Results.

ERIC Educational Resources Information Center

National Assessment Governing Board, Washington, DC.

The National Assessment Governing Board has recognized the need to study associated policy and technical issues to ensure that the National Assessment of Educational Progress (NAEP) is ready to do the best job possible if called on to confirm the results of state achievement testing under the No Child Left Behind Act. This report describes the…

1300929

NASA Image and Video Library

2013-08-15

ARTHUR BROWN (AST, AEROSPACE METALLIC MATERIALS) LOADS A CERAMIC COATED SILICON WAFER INTO A KRATOS (ELECTRON SPECTROSCOPY FOR CHEMICAL ANALYSIS) TO PERFORM X-RAY PHOTOELECTRON SPECTROSCOPY (XPS). XPS IS A TECHNIQUE THAT ANALYZES THE SURFACE CHEMISTRY OF A SAMPLE BY IRRADIATING IT WITH X-RAYS AND MEASURING THE NUMBER AND KINETIC ENERGY OF ELECTRON THAT ESCAPE.

Low-cost and eco-friendly nebulizer spray coated CuInAlS2 counter electrode for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Dhas, C. Ravi; Christy, A. Jennifer; Venkatesh, R.; Esther Santhoshi Monica, S.; Panda, Subhendu K.; Subramanian, B.; Ravichandran, K.; Sudhagar, P.; Raj, A. Moses Ezhil

2018-05-01

CuInAlS2 thin films for different substrate temperatures were deposited by a novel nebulizer spray technique. The polycrystalline CIAS thin film exhibited tetragonal structure with the preferential orientation of (1 1 2) plane. Nanoflakes were observed from the surface morphology of CIAS film. The peak position of core level spectra confirms the presence of CuInAlS2 from XPS analysis. The absorbance spectra and optical band gap were observed from the optical property. The activation energy, carrier concentration, hole mobility and resistivity were determined by linear four probe and Hall effect measurements. The CIAS film was used as a counter electrode (CE) in dye-sensitized solar cells (DSSCs) and is characterized by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel measurements. DSSC fabricated with the CIAS CE achieved the photo conversion efficiency of about 2.55%.

The Relationship Between the Expansion Speed and Radial Speed of CMEs Confirmed Using Quadrature Observations of the 2011 February 15 CME

NASA Astrophysics Data System (ADS)

Gopalswamy, N.; Makela, P.; Yashiro, S.; Davila, J. M.

2012-08-01

It is difficult to measure the true speed of Earth-directed CMEs from a coronagraph along the Sun-Earth line because of the occulting disk. However, the expansion speed (the speed with which the CME appears to spread in the sky plane) can be measured by such coronagraph. In order to convert the expansion speed to radial speed (which is important for space weather applications) one can use empirical relationship between the two that assumes an average width for all CMEs. If we have the width information from quadrature observations, we can confirm the relationship between expansion and radial speeds derived by Gopalswamy et al. (2009a). The STEREO spacecraft were in qudrature with SOHO (STEREO-A ahead of Earth by 87oand STEREO-B 94obehind Earth) on 2011 February 15, when a fast Earth-directed CME occurred. The CME was observed as a halo by the Large-Angle and Spectrometric Coronagraph (LASCO) on board SOHO. The sky-plane speed was measured by SOHO/LASCO as the expansion speed, while the radial speed was measured by STEREO-A and STEREO-B. In addition, STEREO-A and STEREO-B images measured the width of the CME, which is unknown from Earth view. From the SOHO and STEREO measurements, we confirm the relationship between the expansion speed (Vexp) and radial speed (Vrad) derived previously from geometrical considerations (Gopalswamy et al. 2009a): Vrad=1/2 (1 + cot w)Vexp, where w is the half width of the CME. STEREO-B images of the CME, we found that CME had a full width of 7 6o, so w=3 8o. This gives the relation as Vrad=1.1 4 Vexp. From LASCO observations, we measured Vexp=897 km/s, so we get the radial speed as 10 2 3 km/s. Direct measurement of radial speed yields 945 km/s (STEREO-A) and 105 8 km/s (STEREO-B). These numbers are different only by 7.6 % and 3.4 % (for STEREO-A and STEREO-B, respectively) from the computed value.

76 FR 42769 - Recordkeeping and Confirmation Requirements for Securities Transactions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Recordkeeping and Confirmation Requirements for Securities Transactions AGENCY: Office of Thrift Supervision (OTS), Treasury. ACTION: Notice... 1995, 44 U.S.C. 3507. The Office of Thrift Supervision within the Department of the Treasury will...

First flux surface measurements on W7-X

NASA Astrophysics Data System (ADS)

Pedersen, Thomas Sunn; Otte, Matthias; Biedermann, Christoph; Bozhenkov, Sergey; Braeuer, Torsten; Lazerson, Samuel; W7-X Team

2015-11-01

Wendelstein 7-X is rapidly approaching first plasma operation. The full operational B-field of 2.5 T has been reached using the 70 superconducting coils. The first flux surface measurements have recently been successfully performed. This talk will describe the W7-X flux surface measurement system, and show and analyze the first results from this diagnostic, which, at the time of writing this abstract, can be summarized as follows: Confirmation of the existence of nested, closed flux surfaces, first measurements of iota, and detection of the expected internal 5/6 island chain of the OP1.1 configuration. The data obtained so far agree with expectations, and provide a first confirmation of the accuracy of the coil geometry and assembly, as well as diagnostic installation. They also confirm that, with respect to the magnetic topology, plasma operation can start. Plans for, and potentially first results of, measurements of any remnant field errors, will be reported separately at this meeting.

KECK/LRIS SPECTROSCOPIC CONFIRMATION OF COMA CLUSTER DWARF GALAXY MEMBERSHIP ASSIGNMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiboucas, Kristin; Tully, R. Brent; Marzke, Ronald O.

2010-11-01

Keck/LRIS multi-object spectroscopy has been carried out on 140 of some of the lowest and highest surface brightness faint (19 < R < 22) dwarf galaxy candidates in the core region of the Coma Cluster. These spectra are used to measure redshifts and establish membership for these faint dwarf populations. The primary goal of the low surface brightness sample is to test our ability to use morphological and surface brightness criteria to distinguish between Coma Cluster members and background galaxies using high resolution Hubble Space Telescope/Advanced Camera for Surveys images. Candidates were rated as expected members, uncertain, or expected background.more » From 93 spectra, 51 dwarf galaxy members and 20 background galaxies are identified. Our morphological membership estimation success rate is {approx}100% for objects expected to be members and better than {approx}90% for galaxies expected to be in the background. We confirm that low surface brightness is a very good indicator of cluster membership. High surface brightness galaxies are almost always background with confusion arising only from the cases of the rare compact elliptical (cE) galaxies. The more problematic cases occur at intermediate surface brightness. Many of these galaxies are given uncertain membership ratings, and these were found to be members about half of the time. Including color information will improve membership determination but will fail for some of the same objects that are already misidentified when using only surface brightness and morphology criteria. cE galaxies with B-V colors {approx}0.2 mag redward of the red sequence in particular require spectroscopic follow up. In a sample of 47 high surface brightness, ultracompact dwarf candidates, 19 objects have redshifts which place them in the Coma Cluster, while another 6 have questionable redshift measurements but may also prove to be members. Redshift measurements are presented and the use of indirect means for establishing cluster

Melorheostosis with recurrent soft-tissue components: a histologically confirmed case.

PubMed

Hasegawa, Shoichi; Kanda, Shotaro; Imada, Hiroki; Yamaguchi, Takehiko; Akiyama, Toru

2017-03-01

Melorheostosis is a very rare disorder characterized by irregular cortical thickening seen on radiographs. In this paper, we present a case of melorheostosis with microscopically confirmed soft-tissue components. The patient was a 51-year-old man who complained of severe pain in the lateral aspect of his right knee. The excision of an ossified soft-tissue lesion relieved intractable pain that had lasted 20 years. Microscopically, the cortex of the affected fibula was composed of thick compact bone and the soft-tissue component consisted of dense compact bone without endochondral ossification. The presence of soft-tissue osseous nodules around the joints is one of the specific conditions for melorheostosis and should be differentiated from synovial chondromatosis. The ossified soft-tissue lesion in our patient is to our knowledge the first reported case of the histologically confirmed soft-tissue component of melorheostosis, which differs from that of synovial chondromatosis.

Mycobacterium avium subspecies paratuberculosis confirmed following serological surveillance of small ruminants in Grenada, West Indies.

PubMed

Kumthekar, Sachin; Manning, Elizabeth J B; Ghosh, Pallab; Tiwari, Keshaw; Sharma, Ravindra N; Hariharan, Harry

2013-07-01

Surveillance for Mycobacterium avium subsp. paratuberculosis (Map) infection in small ruminants of Grenada was undertaken using a commercial enzyme-linked immunosorbent assay (ELISA). Among the 479 sheep tested, 11 (2.3%) were ELISA positive while only 1 out of 260 goats (0.3%) was ELISA positive. Five of the 12 ELISA-positive animals were also positive in a commercial agar gel immunodiffusion (AGID) assay, and 4 of these showed acid-fast rods consistent with Map in fecal smears. Two sheep that were test-positive by ELISA, AGID, and fecal smears were euthanized and necropsied. Both had gross and histological lesions of paratuberculosis affecting the ileocecal area of small intestines and adjacent lymph nodes. These tissues were successfully cultured in 2 of 3 variants of Middlebrook 7H10 medium. The identity of acid-fast organisms isolated from the tissues was confirmed as Map by multiplex conventional polymerase chain reaction. Using IS1311 amplification and Hinf I restriction digest analysis, isolates were identified as cattle (C) strains of Map. The current study describes Map infection in Grenada and confirms the presence of C type in sheep on the island of Carriacou. The low seroprevalence in clinically normal animals on the islands of Grenada and Carriacou suggests that control measures implemented in the near future may have a good chance of preventing spread of the infection.

Molecular confirmation of Lassa fever imported into Ghana

PubMed Central

Nyarko, Edward O.; Ohene, Sally-Ann; Amankwa, Joseph; Ametepi, Ralph K.; Nimo-Paintsil, Shirley C.; Sarkodie, Badu; Agbenohevi, Prince; Adjabeng, Michael; Kyei, Nicholas N.A.; Bel-Nono, Samuel; Ampofo, William K.

2016-01-01

Background Recent reports have shown an expansion of Lassa virus from the area where it was first isolated in Nigeria to other areas of West Africa. Two Ghanaian soldiers on a United Nations peacekeeping mission in Liberia were taken ill with viral haemorrhagic fever syndrome following the death of a sick colleague and were referred to a military hospital in Accra, Ghana, in May 2013. Blood samples from the soldiers and five asymptomatic close contacts were subjected to laboratory investigations. Objective We report the results of these investigations to highlight the importance of molecular diagnostic applications and the need for heightened awareness about Lassa fever in West Africa. Methods We used molecular assays on sera from the two patients to identify the causative organism. Upon detection of positive signals for Lassa virus ribonucleic material by two different polymerase chain reaction assays, sequencing and phylogenetic analyses were performed. Results The presence of Lassa virus in the soldiers’ blood samples was shown by L-gene segment homology to be the Macenta and las803792 strains previously isolated in Liberia, with close relationships then confirmed by phylogenetic tree construction. The five asymptomatic close contacts were negative for Lassa virus. Conclusions The Lassa virus strains identified in the two Ghanaian soldiers had molecular epidemiological links to strains from Liberia. Lassa virus was probably responsible for the outbreak of viral haemorrhagic fever in the military camp. These data confirm Lassa fever endemicity in West Africa. PMID:28879105

Molecular confirmation of Lassa fever imported into Ghana.

PubMed

Bonney, Joseph H K; Nyarko, Edward O; Ohene, Sally-Ann; Amankwa, Joseph; Ametepi, Ralph K; Nimo-Paintsil, Shirley C; Sarkodie, Badu; Agbenohevi, Prince; Adjabeng, Michael; Kyei, Nicholas N A; Bel-Nono, Samuel; Ampofo, William K

2016-01-01

Recent reports have shown an expansion of Lassa virus from the area where it was first isolated in Nigeria to other areas of West Africa. Two Ghanaian soldiers on a United Nations peacekeeping mission in Liberia were taken ill with viral haemorrhagic fever syndrome following the death of a sick colleague and were referred to a military hospital in Accra, Ghana, in May 2013. Blood samples from the soldiers and five asymptomatic close contacts were subjected to laboratory investigations. We report the results of these investigations to highlight the importance of molecular diagnostic applications and the need for heightened awareness about Lassa fever in West Africa. We used molecular assays on sera from the two patients to identify the causative organism. Upon detection of positive signals for Lassa virus ribonucleic material by two different polymerase chain reaction assays, sequencing and phylogenetic analyses were performed. The presence of Lassa virus in the soldiers' blood samples was shown by L-gene segment homology to be the Macenta and las803792 strains previously isolated in Liberia, with close relationships then confirmed by phylogenetic tree construction. The five asymptomatic close contacts were negative for Lassa virus. The Lassa virus strains identified in the two Ghanaian soldiers had molecular epidemiological links to strains from Liberia. Lassa virus was probably responsible for the outbreak of viral haemorrhagic fever in the military camp. These data confirm Lassa fever endemicity in West Africa.

Metal-passivated PbS nanoparticles: fabrication and characterization.

PubMed

Tchaplyguine, M; Mikkelä, M-H; Mårsell, E; Polley, C; Mikkelsen, A; Zhang, W; Yartsev, A; Hetherington, C J D; Wallenberg, L R; Björneholm, O

2017-03-08

Organic-shell-free PbS nanoparticles have been produced in the size range relevant for quantum-dot solar cells (QDSCs) by a vapor aggregation method involving magnetron reactive sputtering. This method creates a beam of free 5-10 nm particles in a vacuum. The dimensions of the particles were estimated after their deposition on a substrate by imaging them using ex situ SEM and HRTEM electron microscopy. The particle structure and chemical composition could be deduced "on the fly", prior to deposition, using X-ray photoelectron spectroscopy (XPS) with tunable synchrotron radiation. Our XPS results suggest that under certain conditions it is possible to fabricate particles with a semiconductor core and 1 to 2 monolayer shells of metallic lead. For this case the absolute energy of the highest occupied molecular orbital (HOMO) in PbS has been determined to be (5.0 ± 0.5) eV below the vacuum level. For such particles deposited on a substrate HRTEM has confirmed the XPS-based conclusions on the crystalline PbS structure of the semiconductor core. Absorption spectroscopy on the deposited film has given a value of ∼1 eV for the lowest exciton. Together with the valence XPS results this has allowed us to reconstruct the energy level scheme of the particles. The results obtained are discussed in the context of the properties of PbS QDSCs.

Dynamometer-based measure of spasticity confirms limited association between plantarflexor spasticity and walking function in persons with multiple sclerosis

PubMed Central

Kremer, Theodore R.; Van Dillen, Linda R.; Wagner, Joanne M.

2017-01-01

The literature shows inconsistent evidence regarding the association between clinically assessed plantarflexor (PF) spasticity and walking function in ambulatory persons with multiple sclerosis (pwMS). The use of a dynamometer-based spasticity measure (DSM) may help to clarify this association. Our cohort included 42 pwMS (27 female, 15 male; age: 42.9 +/− 10.2 yr) with mild clinical disability (Expanded Disability Status Scale score: 3.6 +/− 1.6). PF spasticity was assessed using a clinical measure, the modified Ashworth Scale (MAS), and an instrumented measure, the DSM. Walking function was assessed by the timed 25-foot walk test (T25FWT), the 6-minute walk test (6MWT), and the 12-item Multiple Sclerosis Walking Scale (MSWS-12). Spearman rho correlations were used to evaluate relationships between spasticity measures, measures of walking speed and endurance, and self-perceived limitations in walking. The correlation was small between PF spasticity and the T25FWT (PF maximum [Max] MAS rho = 0.27, PF Max DSM rho = 0.26), the 6MWT (PF Max MAS rho = −0.20, PF Max DSM rho = −0.21), and the MSWS-12 (PF Max MAS rho = 0.11, PF Max DSM rho = 0.26). Our results are similar to reports in other neurologic clinical populations, wherein spasticity has a limited association with walking dysfunction. PMID:25356797