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Sample records for comparative nexafs examination

  1. Electronic structure modification and Fermi level shifting in niobium-doped anatase titanium dioxide thin films: a comparative study of NEXAFS, work function and stiffening of phonons.

    PubMed

    Gautam, Subodh K; Das, Arkaprava; Ojha, S; Shukla, D K; Phase, D M; Singh, Fouran

    2016-02-01

    The electronic structure and tuning of work function (WF) by electronic excitations (EEs) induced by swift heavy ions (SHIs) in anatase niobium-doped titanium dioxide (NTO) thin films is reported. The densities of EEs were varied using 80 MeV O, 130 MeV Ni and 120 MeV Ag ions for irradiation. The EE-induced modifications in electronic structure were studied by O K-edge and Ti L3,2 edge absorption spectra using near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The reduction of hybridized O 2p and Ti 3d unoccupied states in the conduction band with a decrease in energy of the crystal field strength of ∼ 480 meV and the correlated effect on the decrease in the WF value of ∼ 520 meV upon increasing the total energy deposition in the lattice are evident from the study of NEXAFS and scanning Kelvin probe microscopy (SKPM), respectively. The observed stiffening in the low frequency Raman mode (LFRM) of ∼ 9 cm(-1) further validates the electronic structure modification under the influence of EE-induced strain in TiO6 octahedra. The reduction of hybridized valence states, stiffening behavior of LFRM and decrease in WF by nano-crystallization followed by amorphization and defects in NTO lattice are explained in terms of continuous, discontinuous amorphous ion tracks containing intestinally created defects and non-stoichiometry in the lattice. These studies are very appropriate for better insights of electronic structure modification during phase transformation and controlled Fermi level shifting, which plays a crucial role in controlling the charge carrier injection efficiency in opto-electronic applications and also provides a deeper understanding of the involved physical processes. PMID:26752253

  2. TXM-NEXAFS of TiO2-Based Nanostructures

    NASA Astrophysics Data System (ADS)

    Guttmann, P.; Bittencourt, C.; Ke, X.; Van Tendeloo, G.; Umek, P.; Arcon, D.; Ewels, C. P.; Rehbein, S.; Heim, S.; Schneider, G.

    2011-09-01

    In this work, electronic properties of individual TiOx-pristine nanoribbons (NR) prepared by hydrothermal treatment of anatase TiO2 micro-particles were studied using the HZB transmission x-ray microscope (TXM) at the BESSY II undulator beamline U41-FSGM. NEXAFS is ideally suited to study TiO2-based materials because both the O K-edge and Ti L-edge features are very sensitive to the local bonding environment, providing diagnostic information about the crystal structures and oxidation states of various forms of titanium oxides and sub-oxides. TXM-NEXAFS combines full-field x-ray microscopy with spectroscopy, allowing the study of the electronic structure of individual nanostructures with spatial resolution better than 25 nm and a spectral resolution of up to E/ΔE = 10000. The typical image field in TXM-NEXAFS measurements is about 10 μm×10 μm, which is large compared to the individual nanoparticle. Therefore, one image stack already contains statistically significant data. In addition, the directional electric field vector (Ē) of the x-rays can be used as a "search tool" for the direction of chemical bonds of the atom selected by its absorption edge.

  3. Sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) of thiol and thioether compounds

    SciTech Connect

    Beyhan, Shirin; Urquhart, Stephen G.; Hu Yongfeng

    2011-06-28

    The speciation and quantification of sulfur species based on sulfur K-edge x-ray absorption spectroscopy is of wide interest, particularly for biological and petroleum science. These tasks require a firm understanding of the sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) spectra of relevant species. To this end, we have examined the gas phase sulfur 1s NEXAFS spectra of a group of simple thiol and thioether compounds. These high-resolution gas phase spectra are free of solid-state broadening, charging, and saturation effects common in the NEXAFS spectra of solids. These experimental data have been further analyzed with the aid of improved virtual orbital Hartree-Fock ab initio calculations. The experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve assignment of spectroscopic features relevant for the speciation and quantification of the sulfur compounds.

  4. NEXAFS and XPS studies of nitrosyl chloride.

    PubMed

    Schio, Luca; Li, Cui; Monti, Susanna; Salén, Peter; Yatsyna, Vasyl; Feifel, Raimund; Alagia, Michele; Richter, Robert; Falcinelli, Stefano; Stranges, Stefano; Zhaunerchyk, Vitali; Carravetta, Vincenzo

    2015-04-14

    The electronic structure of nitrosyl chloride (ClNO) has been investigated in the gas phase by X-ray Photoelectron (XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy at the Cl 2p, Cl 2s, N 1s and O 1s edges in a combined experimental and theoretical study. The theoretical calculations at different levels of approximation predict ionization potential values in good agreement with the experimental data and allow us to assign the main features of the absorption spectra. An unexpected failure of the density functional model is, however, observed in the calculation of the Cl 2s binding energy, which is related to a large self-interaction error. Largely different photoabsorption cross-section patterns are experimentally observed in core excitations from the investigated quantum shells (n = 1, 2). This finding is confirmed by the oscillator strength distributions calculated at different absorption edges; in the case of the n = 2 shell the bands below the threshold are extremely weak and most of the absorption intensity is due to excitations in the continuum. PMID:25754872

  5. TXM-NEXAFS of TiO{sub 2}-Based Nanostructures

    SciTech Connect

    Guttmann, P.; Rehbein, S.; Heim, S.; Schneider, G.; Bittencourt, C.; Ke, X.; Van Tendeloo, G.; Umek, P.; Arcon, D.; Ewels, C. P.

    2011-09-09

    In this work, electronic properties of individual TiO{sub x}-pristine nanoribbons (NR) prepared by hydrothermal treatment of anatase TiO{sub 2} micro-particles were studied using the HZB transmission x-ray microscope (TXM) at the BESSY II undulator beamline U41-FSGM. NEXAFS is ideally suited to study TiO{sub 2}-based materials because both the O K-edge and Ti L-edge features are very sensitive to the local bonding environment, providing diagnostic information about the crystal structures and oxidation states of various forms of titanium oxides and sub-oxides. TXM-NEXAFS combines full-field x-ray microscopy with spectroscopy, allowing the study of the electronic structure of individual nanostructures with spatial resolution better than 25 nm and a spectral resolution of up to E/{Delta}E = 10000. The typical image field in TXM-NEXAFS measurements is about 10 {mu}mx10 {mu}m, which is large compared to the individual nanoparticle. Therefore, one image stack already contains statistically significant data. In addition, the directional electric field vector (E-bar) of the x-rays can be used as a 'search tool' for the direction of chemical bonds of the atom selected by its absorption edge.

  6. Composition and Morphology of Individual Combustion, Biomass Burning, and Secondary Organic Particle Types Obtained Using ATOFMS and STXM-NEXAFS Measurements (Invited)

    NASA Astrophysics Data System (ADS)

    Russell, L. M.; Bahadur, R.; Liu, S.; Takahama, S.; Prather, K. A.

    2010-12-01

    Complementary single particle measurements of organic aerosols using aerosol time-of-flight mass spectrometry (ATOFMS) and Scanning Transmission X-ray Microscopy—Near Edge X-ray Absorption Fine Structure (STXM-NEXAFS) are compared to examine the relationships between particle morphologies and chemical composition of particles having similar sources. ATOFMS measurements from field campaigns in polluted or urban (Riverside/SOAR 2005; Mexico City/MILAGRO 2006; Port of Long Beach 2007) and clean or marine (Arabian Sea/INDOEX 1999; Sea of Japan/ACE-Asia 2001; Trinidad Head/CIFEX 2004) locations illustrate regional differences in the amount and types of organic particles. The majority (≥ 85%) of the number of submicron particles are carbonaceous (including elemental and organic carbon), but represent less than 10% of the number of supermicron particles. Organic carbon (OC) particles are classified into three meta-classes corresponding to (1) combustion-generated OC/EC internalmixtures, (2) biomass burning generated K/OC mixtures, and (3) OC/High MassOC (HMOC) mixtures containing secondary markers of atmospheric processing. Normalized dot products are used to quantify similarity among fragment spectra and indicate that OC particle types are consistent across (and within) platforms. Single particle carbon STXM-NEXAFS measurements during ACE-Asia 2001 and MILAGRO 2006 yield similar source categories based on relative abundances of aromatic, alkane, and carboxylic acid functional groups. All three organic particle types correspond to a variety of very heterogeneous particle morphologies, although the highly oxygenated OC particles with likely secondary organic contributions frequently are nearly spherical, liquid-like particles. Similar particle types are observed at many other locations, including recent measurements at Bakersfield, Tijuana, and the R/V Atlantis as part of CalNex and CalMex. Size-resolved number fractions of the major ATOFMS organic particle types show

  7. NEXAFS Study of Air Oxidation for Mg Nanoparticle Thin Film

    NASA Astrophysics Data System (ADS)

    Ogawa, S.; Murakami, S.; Shirai, K.; Nakanishi, K.; Ohta, T.; Yagi, S.

    2013-03-01

    The air oxidation reaction of Mg nanoparticle thin film has been investigated by Mg K-edge NEXAFS technique. It is revealed that MgO is formed on the Mg nanoparticle surfaces at the early stage of the air oxidation for Mg nanoparticle thin film. The simulation of NEXAFS spectrum using standard spectra indicates the existence of complex magnesium carbonates (x(MgCO3).yMg(OH2).z(H2O)) in addition to MgO at the early stage of the air oxidation.

  8. The Structure of p-Aminobenzoic Acid in Water: Studies Combining UV-Vis, NEXAFS and RIXS Spectroscopies

    NASA Astrophysics Data System (ADS)

    Gainar, A.; Stevens, J. S.; Suljoti, E.; Xiao, J.; Golnak, R.; Aziz, E. F.; Schroeder, S. L. M.

    2016-05-01

    NEXAFS-RIXS and home laboratory-based UV-Vis absorption spectroscopy are combined to examine the speciation and electronic structure of para-aminobenzoic acid (PABA) in aqueous solution as a function of pH. DFT and TD-DFT electronic structure calculations reproduce the experimental trends and provide a correlation between the experimental HOMO↔LUMO gap as well as the electronic transitions between molecular orbitals in the non-ionic, anionic and cationic forms of PABA.

  9. On the importance of nuclear quantum motions in near edge x-ray absorption fine structure (NEXAFS) spectroscopy of molecules

    SciTech Connect

    Schwartz, Craig P.; Uejio, Janel S.; Saykally, Richard J.; Prendergast, David

    2009-02-26

    We report the effects of sampling nuclear quantum motion with path integral molecular dynamics (PIMD) on calculations of the nitrogen K-edge spectra of two isolated organic molecules. S-triazine, a prototypical aromatic molecule occupying primarily its vibrational ground state at room temperature, exhibits substantially improved spectral agreement when nuclear quantum effects are included via PIMD, as compared to the spectra obtained from either a single fixed-nuclei based calculation or from a series of configurations extracted from a classical molecular dynamics trajectory. Nuclear quantum dynamics can accurately explain the intrinsic broadening of certain features. Glycine, the simplest amino acid, is problematic due to large spectral variations associated with multiple energetically accessible conformations at the experimental temperature. This work highlights the sensitivity of NEXAFS to quantum nuclear motions in molecules, and the necessity of accurately sampling such quantum motion when simulating their NEXAFS spectra.

  10. Vulcanization reaction of squalene and S8 powder studied by Sulfur K-edge NEXAFS under liquid phase

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    Vulcanized rubber materials are useful in our surroundings. However, detail structure and reaction are not revealed even in present. Since squalene molecule possesses some same properties compared with natural rubber, we have prepared the samples of vulcanized squalene at 140 °C for several hours. To understand the vulcanization reaction,sulfur K-edge NEXAFS measurements have been carried out for the vulcanized squalene under liquid phase with He-path system and fluorescence detection mode. Moreover, we have tried curve fitting analysis of NEXAFS spectra. The results indicate that the squalene has been vulcanized by the S8 molecule at 140 °C and the S8 molecule length is shortened from 8 to 5-6 after the vulcanization reaction.

  11. NEXAFS and XMCD studies of single-phase Co doped ZnO thin films.

    PubMed

    Singh, Abhinav Pratap; Kumar, Ravi; Thakur, P; Brookes, N B; Chae, K H; Choi, W K

    2009-05-01

    A study of the electronic structure and magnetic properties of Co doped ZnO thin films synthesized by ion implantation followed by swift heavy ion irradiation is presented using near-edge x-ray absorption fine structure (NEXAFS) and x-ray magnetic circular dichroism (XMCD) measurements. The spectral features of NEXAFS at the Co L(3,2)-edge show entirely different features than that of metallic Co clusters and other Co oxide phases. The atomic multiplet calculations are performed to determine the valence state, symmetry and the crystal field splitting, which show that in the present system Co is in the 2+ state and substituted at the Zn site in tetrahedral symmetry with 10Dq = -0.6 eV. The ferromagnetic character of these materials is confirmed through XMCD spectra. To rule out the possibilities of defect induced magnetism, the results are compared with Ar annealed and Ar-ion implanted pure ZnO thin films. The presented results confirm the substitution of Co at the Zn site in the ZnO matrix, which is responsible for room temperature ferromagnetism. PMID:21825451

  12. Aging induced changes on NEXAFS fingerprints in individual combustion particles

    NASA Astrophysics Data System (ADS)

    Zelenay, V.; Mooser, R.; Tritscher, T.; Křepelová, A.; Heringa, M. F.; Chirico, R.; Prévôt, A. S. H.; Weingartner, E.; Baltensperger, U.; Dommen, J.; Watts, B.; Raabe, J.; Huthwelker, T.; Ammann, M.

    2011-11-01

    Soot particles can significantly influence the Earth's climate by absorbing and scattering solar radiation as well as by acting as cloud condensation nuclei. However, despite their environmental (as well as economic and political) importance, the way these properties are affected by atmospheric processing of the combustion exhaust gases is still a subject of discussion. In this work, individual soot particles emitted from two different vehicles, a EURO 2 transporter, a EURO 3 passenger car, and a wood stove were investigated on a single-particle basis. The emitted exhaust, including the particulate and the gas phase, was processed in a smog chamber with artificial solar radiation. Single particle specimens of both unprocessed and aged soot were characterized using near edge X-ray absorption fine structure spectroscopy (NEXAFS) and scanning electron microscopy. Comparison of NEXAFS spectra from the unprocessed particles and those resulting from exhaust photooxidation in the chamber revealed changes in the carbon functional group content. For the wood stove emissions, these changes were minor, related to the relatively mild oxidation conditions. For the EURO 2 transporter emissions, the most apparent change was that of carboxylic carbon from oxidized organic compounds condensing on the primary soot particles. For the EURO 3 car emissions oxidation of primary soot particles upon photochemical aging has likely contributed as well. Overall, the changes in the NEXAFS fingerprints were in qualitative agreement with data from an aerosol mass spectrometer. Furthermore, by taking full advantage of our in situ microreactor concept, we show that the soot particles from all three combustion sources changed their ability to take up water under humid conditions upon photochemical aging of the exhaust. Due to the selectivity and sensitivity of the NEXAFS technique for the water mass, also small amounts of water taken up into the internal voids of agglomerated particles could be

  13. The NEXAFS of biological calcium phosphates

    SciTech Connect

    Buckley, C.J.; Bellamy, S.J. ); Zhang, X. ); Dermody, G. ); Hulbert, S. )

    1995-02-01

    The absorption cross section of a number of calcium salts has been assessed at the calcium [ital L] edge by measuring the total electron yield (TEY) at the NSLS U13UA beamline. TEY was used because of distortions introduced by instrumentation when using a transmission signal. The effect of these distortions has been evaluated and is presented. The TEY signal was normalized to the incident beam using the signal from a new beam monitor which is detailed here. Comparative spectra are presented for some calcium salts associated with osteoarthritis.

  14. Tradeoffs in Examination Policies: An International Comparative Perspective.

    ERIC Educational Resources Information Center

    Noah, Harold J.; Eckstein, Max A.

    1989-01-01

    Reports on recent changes in examination policy and practice in China, England and Wales, the Federal Republic of Germany, France, Japan, Sweden, the United States, and the Soviet Union. Identifies and discusses some significant trade-offs arising from the implementation of examination policy. Discusses four nearly universal dilemmas of…

  15. High-Throughput Analysis of Molecular Orientation on Surfaces by NEXAFS Imaging of Curved Sample Arrays

    PubMed Central

    Baio, Joe E.; Jaye, Cherno; Fischer, Daniel A.; Weidner, Tobias

    2015-01-01

    Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy provides detailed information about the orientation and alignment of thin films. NEXAFS is a synchrotron-based technique—the availability of beam-time per user is typically limited to no more than a few weeks per year. The limited availability is currently a true barrier for using NEXAFS in combinatorial studies of molecular alignment. We have recently demonstrated how large area full field NEXAFS imaging allows users to pursue combinatorial studies of surface chemistry. Now we report an extension of this approach which allows the acquisition of orientation information from a single NEXAFS image. An array with 80 elements (samples), containing eight series of different surface modifications, was mounted on a curved substrate allowing the collection of NEXAFS spectra with a range of orientations with respect to the X-ray beam. Images collected from this array show how hyperspectral NEXAFS data collected from curved surfaces can be used for high-throughput molecular orientation analysis. PMID:25046426

  16. Primary and Secondary Contributions to the Organic Aerosol Over the Amazon Determined by STXM-NEXAFS

    NASA Astrophysics Data System (ADS)

    Andreae, M. O.; Pöhlker, C.; Wiedemann, K. T.; Sinha, B.; Artaxo, P.; Kilcoyne, D.; Smith, M. L.; Martin, S. T.; Poeschl, U.

    2011-12-01

    We investigated the morphology and chemical composition of aerosol samples from a pristine tropical environment, the Amazon Basin, using Scanning Transmission X-ray Microscopy - Near Edge X-ray Absorption Fine Structure (STXMNEXAFS) analysis. The NEXAFS spectra were used to estimate the elemental ratios of C, N and O, as well as the chemical bonding state of these elements. The aim of this study was to investigate the microphysical and chemical properties of a tropical background aerosol and its internal mixing state. The samples were collected in the Amazonian rainforest during the rainy season and can be regarded as a nearly pristine background aerosol. Lab-generated SOA-samples (produced by the (photo)oxidation of isoprene, alpha-pinene and beta-caryophyllene), microtome slices of fungal spores, and aerosolized authentic organic compounds were measured as reference samples. The STXM-NEXAFS results of the lab-generated SOA have been analyzed and compared to SOA from the Amazonian region. In the lab samples, SOA occurred as droplets of different sizes, sometimes exhibiting internal structures ('raisin-like' structure). The spectral characteristics of the lab samples depend on the precursors applied for their generation. The Amazonian aerosol was found to be dominated by drop-like organic particles in the fine mode (often in internal mixture with solid particles), and Primary Biological Aerosol Particles (PBAP) in the coarse mode. Liquid organic aerosol coatings were also frequently observed on the PBAPs. Unexpectedly, many ambient SOA samples show a high content of N (around 20% or even more) as well as the frequent occurrence of potassium. Furthermore, the spectra exhibit characteristic signal patterns for different functional groups. In most cases, the spectrum near the C-edge is dominated by either the hydroxyl or the carboxylate signal, but prominent peaks for ketone carbonyls, alkanes and alkenes have also been observed. Based on these results, a new

  17. NEXAFS Depth Profiling of Surface Segregation in Block Copolymer Thin Films

    SciTech Connect

    Krishnan, S.; Paik, M; Ober, C; Martinelli, E; Galli, G; Sohn, K; Kramer, E; Fischer, D

    2010-01-01

    NEXAFS spectroscopy was used to probe the surface composition and under-water surface reconstruction of thin films of comb-like diblock copolymers with cylindrical and spherical microphases. The polymers consisted of a polystyrene block, and a second block prepared from a styrenic monomer grafted with fluoroalkyl-tagged poly(ethylene glycol) side chains. Compositional depth profiling of the microphase separated block copolymer films, in the top 1-3 nm of the film, was performed to understand the role of block copolymer microstructure and self-assembly on surface composition. Using experimentally determined concentration profiles, the surface concentration of phenyl ring carbon atoms was quantified and compared with those of homopolymer and random copolymer controls. The carbon atoms from the relatively high surface energy phenyl groups were depleted or excluded from the surface, in favor of the low surface-energy fluoroalkyl groups. While it is expected that block copolymer surfaces will be completely covered by a wetting lamellar layer of the lower surface energy block, a significant amount of the higher surface energy polystyrene block was found to be present in the surface region of the cylinder-forming block copolymer. Evidently, the spontaneous formation of the cylindrical polystyrene microdomains in the near-surface region compensated for the lowering of the free energy that could have been achieved by completely covering the surfaces with a lamellar layer of the lower surface energy fluorinated block. All surfaces underwent molecular reconstruction after immersion in water. The experimental concentration depth profiles indicated an increased surface depletion of phenyl ring carbon atoms in the water-immersed thin films, due to the tendency of hydrophilic PEG side groups to be present at the polymer-water interface. Such a detailed characterization of the outermost layers of the block copolymer surfaces was possible because of the exceptional depth resolution

  18. Youth, Life, and Politics: Examining the Everyday in Comparative Politics

    ERIC Educational Resources Information Center

    Ortuoste, Maria

    2012-01-01

    The traditional way of introducing comparative politics to freshmen, which is through the study of institutions, is contrasted with an alternative approach. An everyday-politics approach compares the daily struggles of global youth--how they cope in times of peace and war, and with issues of wealth and poverty, identity, education and employment,…

  19. Comparative Television Advertising: Examining Its Nature and Frequency

    ERIC Educational Resources Information Center

    Brown, Stephen W.; Jackson, Donald W.

    1977-01-01

    Reports on the findings of a content analysis of 896 nationally televised advertisements which showed that strictly defined, comparative advertisements are a relatively small percentage of total national television advertisements and that certain product types (drugs, household, and foods) are more likely to utilize comparisons. (MB)

  20. Comparative examination of probe labeling methods for microarray hybridization

    NASA Astrophysics Data System (ADS)

    Burke, David I.; Woodward, Karen; Setterquist, Robert A.; Kawasaki, Ernest S.

    2001-06-01

    For detection of differential gene expression, confocal laser based scanners are now capable of analyzing microarrays using one to five wavelengths. This allows investigators to choose among several labeling methods. Here we compare direct incorporation and indirect methods (amino-allyl and dendrimers) for labeling cDNA probes. We assessed reproducible sensitivity of each probe preparation method in two ways. First, by comparing hybridization intensities for limit of signal detection and second by measuring the lowest detectable concentration of a known ratio of mixed DNA (spikes). Limit of detection assay was done using arrays of mixed targets consisting of a serially diluted human specific gene fragment (HU1) and an undiluted DNA of chloramphenicol acetyl tranferase (CAT) gene. Then, individual single target arrays of CAT and HU1 DNA were used to determine the lowest detectable spike ratio of each labeling method. The results of this study will be presented and their significance for the analysis of microarrays will be discussed.

  1. Comparative testing of nondestructive examination techniques for concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight A.; Smith, Cyrus M.

    2014-03-01

    A multitude of concrete-based structures are typically part of a light water reactor (LWR) plant to provide foundation, support, shielding, and containment functions. Concrete has been used in the construction of nuclear power plants (NPPs) because of three primary properties, its inexpensiveness, its structural strength, and its ability to shield radiation. Examples of concrete structures important to the safety of LWR plants include containment building, spent fuel pool, and cooling towers. Comparative testing of the various NDE concrete measurement techniques requires concrete samples with known material properties, voids, internal microstructure flaws, and reinforcement locations. These samples can be artificially created under laboratory conditions where the various properties can be controlled. Other than NPPs, there are not many applications where critical concrete structures are as thick and reinforced. Therefore, there are not many industries other than the nuclear power plant or power plant industry that are interested in performing NDE on thick and reinforced concrete structures. This leads to the lack of readily available samples of thick and heavily reinforced concrete for performing NDE evaluations, research, and training. The industry that typically performs the most NDE on concrete structures is the bridge and roadway industry. While bridge and roadway structures are thinner and less reinforced, they have a good base of NDE research to support their field NDE programs to detect, identify, and repair concrete failures. This paper will summarize the initial comparative testing of two concrete samples with an emphasis on how these techniques could perform on NPP concrete structures.

  2. [Comparative examination of preparation time in docetaxel hydrate formulation].

    PubMed

    Arii, Daisuke; Ikeno, Yohei; Narita, Kumi; Murooka, Kunihiko; Nojima, Michio; Kidokoro, Akio

    2012-12-01

    Docetaxel hydrate(DTX), a taxane anticancer drug, is known to be effective against a wide range of cancers, including breast cancer and non-small cell lung cancer. The DTX preparation Taxotere(2-vial DTX)has conventionally required dissolution in the attached solvent, while Onetaxotere(1-vial DTX), a newer product, is provided as a solution. This allows reduction of preparation time, so that improvement in operational efficiency can be expected. In this study, we measured the actual preparation time for 2-vial DTX and 1-vial DTX to compare their usefulness. The median preparation time for 2-vial DTX(n=84)and 1-vial DTX(n=84)was significantly different, with the respective values being 6. 52 minutes and 2. 67 minutes(p<0. 01). By switching to 1-vial DTXfrom 2-vial DTX, which requires preparation of a premix solution with the attached solvent, the preparation procedure in daily practice becomes more convenient. This is because of a shorter preparation time as well as a lower risk of contamination, suggesting the usefulness of 1-vial DTX. PMID:23235174

  3. Nanoscale spectroscopy with polarized X-rays by NEXAFS-TXM

    NASA Astrophysics Data System (ADS)

    Guttmann, Peter; Bittencourt, Carla; Rehbein, Stefan; Umek, Polona; Ke, Xiaoxing; van Tendeloo, Gustaaf; Ewels, Chris P.; Schneider, Gerd

    2012-01-01

    Near-edge X-ray absorption spectroscopy (NEXAFS) is an essential analytical tool in material science. Combining NEXAFS with scanning transmission X-ray microscopy (STXM) adds spatial resolution and the possibility to study individual nanostructures. Here, we describe a full-field transmission X-ray microscope (TXM) that generates high-resolution, large-area NEXAFS data with a collection rate two orders of magnitude faster than is possible with STXM. The TXM optical design combines a spectral resolution of E/ΔE = 1 × 104 with a spatial resolution of 25 nm in a field of view of 15-20 µm and a data acquisition time of ~1 s. As an example, we present image stacks and polarization-dependent NEXAFS spectra from individual anisotropic sodium and protonated titanate nanoribbons. Our NEXAFS-TXM technique has the advantage that one image stack visualizes a large number of nanostructures and therefore already contains statistical information. This new high-resolution NEXAFS-TXM technique opens the way to advanced nanoscale science studies.

  4. Self-association of organic solutes in solution: a NEXAFS study of aqueous imidazole.

    PubMed

    Thomason, M J; Seabourne, C R; Sattelle, B M; Hembury, G A; Stevens, J S; Scott, A J; Aziz, E F; Schroeder, S L M

    2015-01-01

    N K-edge near-edge X-ray absorption fine-structure (NEXAFS) spectra of imidazole in concentrated aqueous solutions have been acquired. The NEXAFS spectra of the solution species differ significantly from those of imidazole monomers in the gas phase and in the solid state of imidazole, demonstrating the strong sensitivity of NEXAFS to the local chemical and structural environment. In a concentration range from 0.5 to 8.2 mol L(-1) the NEXAFS spectrum of aqueous imidazole does not change strongly, confirming previous suggestions that imidazole self-associates are already present at concentrations more dilute than the range investigated here. We show that various types of electronic structure calculations (Gaussian, StoBe, CASTEP) provide a consistent and complete interpretation of all features in the gas phase and solid state spectra based on ground state electronic structure. This suggests that such computational modelling of experimental NEXAFS will permit an incisive analysis of the molecular interactions of organic solutes in solutions. It is confirmed that microhydrated clusters with a single imidazole molecule are poor models of imidazole in aqueous solution. Our analysis indicates that models including both a hydrogen-bonded network of hydrate molecules, and imidazole-imidazole interactions, are necessary to explain the electronic structure evident in the NEXAFS spectra. PMID:25873522

  5. A detailed assignment of NEXAFS resonances of imidazolium based ionic liquids.

    PubMed

    Ehlert, Christopher; Holzweber, Markus; Lippitz, Andreas; Unger, Wolfgang E S; Saalfrank, Peter

    2016-03-16

    In Near Edge X-Ray Absorption Fine Structure (NEXAFS) spectroscopy X-Ray photons are used to excite tightly bound core electrons to low-lying unoccupied orbitals of the system. This technique offers insight into the electronic structure of the system as well as useful structural information. In this work, we apply NEXAFS to two kinds of imidazolium based ionic liquids ([CnC1im](+)[NTf2](-) and [C4C1im](+)[I](-)). A combination of measurements and quantum chemical calculations of C K and N K NEXAFS resonances is presented. The simulations, based on the transition potential density functional theory method (TP-DFT), reproduce all characteristic features observed by the experiment. Furthermore, a detailed assignment of resonance features to excitation centers (carbon or nitrogen atoms) leads to a consistent interpretation of the spectra. PMID:26948544

  6. Do Different Approaches to Examining Construct Comparability in Multilanguage Assessments Lead to Similar Conclusions?

    ERIC Educational Resources Information Center

    Oliveri, Maria E.; Ercikan, Kadriye

    2011-01-01

    In this study, we examine the degree of construct comparability and possible sources of incomparability of the English and French versions of the Programme for International Student Assessment (PISA) 2003 problem-solving measure administered in Canada. Several approaches were used to examine construct comparability at the test- (examination of…

  7. Density functional theory study of NEXAFS spectra of 4-methylbenzenethiol molecule

    NASA Astrophysics Data System (ADS)

    Song, Xiuneng; Wang, Guangwei; Ma, Yong; Jiang, Shouzhen; Yue, Weiwei; Xu, Shicai; Wang, Chuankui

    2016-02-01

    We have employed density functional theory (DFT) to calculate the carbon K-edge NEXAFS spectroscopy of 4-methylbenzenethiol (4-MBT) on gold surface. Polarization-dependent NEXAFS spectra of 4-MBT at different orientation angles are systematically analyzed. The π* resonance at 285 eV, which is the result of the transitions from 1s orbitals of carbon atoms in benzene ring to the lowest unoccupied molecular orbital (LUMO), is selected to study the orientation of 4-MBT molecule on the gold surface. In comparison with the experimental results, it is found that the benzene ring of 4-MBT is tilted by 33° with respect to the gold surface.

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

    SciTech Connect

    Lee,C.; Gong, P.; Harbers, G.; Grainger, D.; Castner, D.; Gamble, L.

    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{yields}{pi}* 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

  9. Conformations of polyaniline molecules adsorbed on Au(111) probed by in situ STM and ex situ XPS and NEXAFS.

    PubMed

    Lee, YiHui; Chang, ChinZen; Yau, ShuehLin; Fan, LiangJen; Yang, YawWen; Yang, LiangYueh Ou; Itaya, Kingo

    2009-05-13

    In situ scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure (NEXAFS) have been used to examine the conformation of a monolayer of polyaniline (PAN) molecules produced on a Au(111) single-crystal electrode by anodization at 1.0 V [vs reversible hydrogen electrode (RHE)] in 0.10 M H(2)SO(4) containing 0.030 M aniline. The as-produced PAN molecules took on a well-defined linear conformation stretching for 500 A or more, as shown by in situ and ex situ STM. The XPS and NEXAFS results indicated that the linear PAN seen at 1.0 V assumed the form of an emeraldine salt made of PAN chains and (bi)sulfate anions. Shifting the potential from 1.0 to 0.7 V altered the shape of the PAN molecules from straight to crooked, which was ascribed to restructuring of the Au(111) electrified interface on the basis of voltammetric and XPS results. In situ STM showed that further decreasing the potential to 0.5 V transformed the crooked PAN threads into a mostly linear form again, with preferential alignment and formation of some locally ordered structures. PAN molecules could be reduced from emeraldine to leucoemeraldine as the potential was decreased to 0.2 V or less. In situ STM showed that the fully reduced PAN molecules were straight but mysteriously shortened to approximately 50 A in length. The conformation of PAN did not recuperate when the potential was shifted positively to 1.0 V. PMID:19361217

  10. Overview of nanoscale NEXAFS performed with soft X-ray microscopes.

    PubMed

    Guttmann, Peter; Bittencourt, Carla

    2015-01-01

    Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM) as well as full-field transmission X-ray microscopes (TXM) allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB) at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples. PMID:25821700

  11. Overview of nanoscale NEXAFS performed with soft X-ray microscopes

    PubMed Central

    Bittencourt, Carla

    2015-01-01

    Summary Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM) as well as full-field transmission X-ray microscopes (TXM) allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB) at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples. PMID:25821700

  12. Factors Influencing Student Preference When Comparing Handwriting and Typing for Essay Style Examinations

    ERIC Educational Resources Information Center

    Mogey, Nora; Fluck, Andrew

    2015-01-01

    It seems anachronistic that we expect students to handwrite essay examinations when almost all their other work is mediated by computer. Two universities, one in the UK and one in Australia, are exploring the use of computers in free text response examinations. This paper compares both the attitudes and the behaviours of their students concerning…

  13. Anatomy Practical Examinations: How Does Student Performance on Computerized Evaluation Compare with the Traditional Format?

    ERIC Educational Resources Information Center

    Inuwa, Ibrahim Muhammad; Taranikanti, Varna; Al-Rawahy, Maimouna; Habbal, Omar

    2012-01-01

    Practical examinations in anatomy are usually conducted on specimens in the anatomy laboratory (referred to here as the "traditional" method). Recently, we have started to administer similar examinations online using the quiz facility in Moodle[TM]. In this study, we compare student scores between two assessment environments viz. online and…

  14. A Comparative Study Examining Academic Cohorts with Transnational Migratory Intentions towards Canada and Australia

    ERIC Educational Resources Information Center

    Hopkins, John

    2016-01-01

    This research examines the issue of transnational academic mobility of academic staff, those choosing to migrate to higher education institutions in different countries as part of their career development, and performs a comparative study between the characteristics of academics examining Australia as a possible migratory destination with those…

  15. Examining Sensory Modulation in Individuals with Autism as Compared to Community Controls

    ERIC Educational Resources Information Center

    Kern, Janet K.; Garver, Carolyn R.; Carmody, Thomas; Andrews, Alonzo A.; Mehta, Jyutika A.; Trivedi, Madhukar H.

    2008-01-01

    The purpose of the study was to examine sensory modulation items on the Sensory Profile in individuals with autism as compared to community controls. The data for this study were collected as part of a cross-sectional study that examined sensory processing, using the Sensory Profile, in 103 individuals with autism and/or pervasive developmental…

  16. The Brief Cognitive Status Examination (BCSE): Comparing Diagnostic Utility and Equating Scores to the Mini-Mental State Examination (MMSE).

    PubMed

    Hilsabeck, Robin C; Holdnack, James A; Cullum, C Munro; Drozdick, Lisa Whipple; Edelstein, Barry; Fiske, Amy; Lacritz, Laura; McCoy, Karin J M; Wahlstrom, Dustin

    2015-08-01

    The study purpose was to compare the diagnostic utility of the Brief Cognitive Status Exam (BCSE) to that of the Mini-Mental State Examination (MMSE) and to develop equated scores to facilitate comparisons. One hundred and eighty-two patients underwent cognitive evaluation and were placed into three groups: dementia (DEM), cognitive impairment, no dementia (CIND), and no cognitive impairment (NCI). One hundred and eighty-two healthy controls from the BCSE standardization sample served as a comparison group. On both measures, the DEM group obtained significantly lower scores than the other two groups, and the CIND group scored significantly lower than the NCI group. The BCSE was more sensitive in all clinical groups, although at extremely low scores, the two tests displayed similar sensitivity. Results indicate the BCSE has diagnostic utility as a cognitive screening measure in a mixed clinical sample and is more sensitive at detecting cognitive impairment, particularly milder levels, than the MMSE. PMID:26085478

  17. Comparability of GCSE Examinations in Different Subjects: An Application of the Rasch Model

    ERIC Educational Resources Information Center

    Coe, Robert

    2008-01-01

    The comparability of examinations in different subjects has been a controversial topic for many years and a number of criticisms have been made of statistical approaches to estimating the "difficulties" of achieving particular grades in different subjects. This paper argues that if comparability is understood in terms of a linking construct then…

  18. NEXAFS and XPS of p-Aminobenzoic Acid Polymorphs: The Influence of Local Environment

    NASA Astrophysics Data System (ADS)

    Stevens, J. S.; Gainar, A.; Jaye, C.; Fischer, D. A.; Schroeder, S. L. M.

    2016-05-01

    Nitrogen K-edge XPS and NEXAFS of the two polymorphic forms of para- aminobenzoic acid (PABA) are significantly different reflecting variation in hydrogen bonding. Alteration in hydrogen bonding at the amino group leads to a shift to high energy for both the XPS N 1s core level and the 3π* NEXAFS resonance with β-PABA. Participation of the amine group in the aromatic system causes the 1π* resonance to be sensitive to the nature of the intermolecular bonding at the para-carboxylic acid group, and a shift to low energy for α- PABA is observed due to hydrogen-bonded carboxylic acid dimer formation. FEFF calculations also successfully reproduce both the energy and intensity variations observed for the σ* shape resonance associated with the C-N bond, with the majority of the decrease in energy observed for b-PABA arising from the longer C-N bond.

  19. Oxidation of a potassium monolayer on Ru(001) studied with photoemission, NEXAFS and vibrational EELS

    NASA Astrophysics Data System (ADS)

    Hoffmann, F. M.; Weisel, M.; Eberhardt, W.; Fu, Zugen

    1990-08-01

    The interaction of oxygen with a monolayer of potassium on a Ru(001) surface has been investigated with photoemission and NEXAFS. O 1s core-level data exhibit for low exposures of oxygen a single peak at 531.8 eV. This indicates together with the earlier observation of KO bond formation by EELS that a single K xO y species with equivalent oxygen atoms is formed. NEXAFS data indicate a partially filled O π* orbital and a strongly shifted σ-resonance. Photoemission, vibrational and Auger data suggest an ionic species which is close to potassium Superoxide with the OO bond oriented parallel to the surface.

  20. Dopamine adsorption on anatase TiO2(101): a photoemission and NEXAFS spectroscopy study.

    PubMed

    Syres, K; Thomas, A; Bondino, F; Malvestuto, M; Grätzel, M

    2010-09-21

    The adsorption of dopamine onto an anatase TiO(2)(101) single crystal has been studied using photoemission and NEXAFS techniques. Photoemission results suggest that the dopamine molecule adsorbs on the surface in a bidentate geometry, resulting in the removal of band gap states in the TiO(2) valence band. Using the searchlight effect, carbon K-edge NEXAFS spectra indicate that the phenyl rings in the dopamine molecules are orientated normal to the surface. A combination of experimental and computational results indicates the appearance of new unoccupied states arising following adsorption. The possible role of these states in the charge-transfer mechanism of the dopamine-TiO(2) system is discussed. PMID:20735026

  1. NEXAFS Chemical State and Bond Lengths of p-Aminobenzoic Acid in Solution and Solid State

    NASA Astrophysics Data System (ADS)

    Stevens, J. S.; Gainar, A.; Suljoti, E.; Xiao, J.; Golnak, R.; Aziz, E. F.; Schroeder, S. L. M.

    2016-05-01

    Solid-state and solution pH-dependent NEXAFS studies allow direct observation of the electronic state of para-aminobenzoic acid (PABA) as a function of its chemical environment, revealing the chemical state and bonding of the chemical species. Variations in the ionization potential (IP) and 1s→π* resonances unequivocally identify the chemical species (neutral, cationic, or anionic) present and the varying local environment. Shifts in σ* shape resonances relative to the IP in the NEXAFS spectra vary with C-N bond length, and the important effect of minor alterations in bond length is confirmed with nitrogen FEFF calculations, leading to the possibility of bond length determination in solution.

  2. Bonding and charge transfer in nitrogen-donor uranyl complexes: insights from NEXAFS spectra.

    PubMed

    Pemmaraju, C D; Copping, Roy; Wang, Shuao; Janousch, Markus; Teat, Simon J; Tyliszcak, Tolek; Canning, Andrew; Shuh, David K; Prendergast, David

    2014-11-01

    We investigate the electronic structure of three newly synthesized nitrogen-donor uranyl complexes [(UO2)(H2bbp)Cl2], [(UO)2(Hbbp)(Py)Cl], and [(UO2)(bbp)(Py)2] using a combination of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy experiments and simulations. The complexes studied feature derivatives of the tunable tridentate N-donor ligand 2,6-bis(2-benzimidazyl)pyridine (bbp) and exhibit discrete chemical differences in uranyl coordination. The sensitivity of the N K-edge X-ray absorption spectrum to local bonding and charge transfer is exploited to systematically investigate the evolution of structural as well as electronic properties across the three complexes. A thorough interpretation of the measured experimental spectra is achieved via ab initio NEXAFS simulations based on the eXcited electron and Core-Hole (XCH) approach and enables the assignment of spectral features to electronic transitions on specific absorbing sites. We find that ligand-uranyl bonding leads to a signature blue shift in the N K-edge absorption onset, resulting from charge displacement toward the uranyl, while changes in the equatorial coordination shell of the uranyl lead to more subtle modulations in the spectral features. Theoretical simulations show that the flexible local chemistry at the nonbinding imidazole-N sites of the bbp ligand is also reflected in the NEXAFS spectra and highlights potential synthesis strategies to improve selectivity. In particular, we find that interactions of the bbp ligand with solvent molecules can lead to changes in ligand-uranyl binding geometry while also modulating the K-edge absorption. Our results suggest that NEXAFS spectroscopy combined with first-principles interpretation can offer insights into the coordination chemistry of analogous functionalized conjugated ligands. PMID:25330350

  3. NEXAFS Sensitivity to Bond Lengths in Complex Molecular Materials: A Study of Crystalline Saccharides.

    PubMed

    Gainar, Adrian; Stevens, Joanna S; Jaye, Cherno; Fischer, Daniel A; Schroeder, Sven L M

    2015-11-12

    Detailed analysis of the C K near-edge X-ray absorption fine structure (NEXAFS) spectra of a series of saccharides (fructose, xylose, glucose, galactose, maltose monohydrate, α-lactose monohydrate, anhydrous β-lactose, cellulose) indicates that the precise determination of IPs and σ* shape resonance energies is sensitive enough to distinguish different crystalline saccharides through the variations in their average C-OH bond lengths. Experimental data as well as FEFF8 calculations confirm that bond length variations in the organic solid state of 10(-2) Å can be experimentally detected, opening up the possibility to use NEXAFS for obtaining incisive structural information for molecular materials, including noncrystalline systems without long-range order such as dissolved species in solutions, colloids, melts, and similar amorphous phases. The observed bond length sensitivity is as good as that originally reported for gas-phase and adsorbed molecular species. NEXAFS-derived molecular structure data for the condensed phase may therefore be used to guide molecular modeling as well as to validate computationally derived structure models for such systems. Some results indicate further analytical value in that the σ* shape resonance analysis may distinguish hemiketals from hemiacetals (i.e., derived from ketoses and aldoses) as well as α from β forms of otherwise identical saccharides. PMID:26459024

  4. Comparing results of clinical versus ultrasonographic examination in developmental dysplasia of hip

    PubMed Central

    Arti, Hamidreza; Mehdinasab, Seyed Abdoulhossein; Arti, Sara

    2013-01-01

    Background: Developmental dysplasia of hip (DDH) is one of the congenital anomalies in newborns that if not diagnosed and treated on time can lead to a severe disability. Although clinical examination is a very useful way for screening, but in some patients, a confirmatory diagnostic method such as ultrasonography is needed. The aim of the present study is to compare the sensitivity and specificity of clinical examination and ultrasonography in early detecting of DDH. Materials and Methods: A total of 5800 of newborns were examined by orthopedic surgeon as a screening method. The newborns with risk factors or suspicious on clinical examination were introduced to repeat clinical and ultrasonographic examination of hip. The results were collected and recorded by a check list and then the sensitivity and specificity of clinical examination were calculated. Results: Of 5701 newborns (11402 hips) who were studied by two methods of clinical examination and ultrasonography (by Graf method), the overall incidence of DDH was 29 per 1000. Only 94 hips (13.5%) of 694 disordered ones according to clinical examination were involved on ultrasonographic evaluation. A total of 240 hips of 334 (72%) involved hips according to ultrasonography (Graf type IIb or more) were diagnosed normal on clinical examination, considering ultrasonography as a gold standard method of evaluating DDH, the sensitivity and specificity of clinical examination were calculated 28.1% and 94.5%, respectively. Conclusion: According to the present study, ultrasonogeraphic examination has a high valuable in screening of DDH and the clinical examination done by an experienced orthopedic surgeon has an acceptable value in primary screening of DDH in developing countries for detecting of healthy neonates, but if the newborn has a risk factor or is suspicious on clinical examination, it will be necessary to get assistance from ultrasonography by an experienced sonographer. PMID:24523795

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

    SciTech Connect

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

    2015-02-07

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

  6. Examination of Remedial Reading and Writing Course Outcomes Using a Causal-Comparative Approach

    ERIC Educational Resources Information Center

    Wilson-Mighty, Roseta

    2011-01-01

    The current study examined differences in student performance and retention rates for those who completed remedial reading or remedial writing courses and those who did not in a private university in South Florida. International students also were compared to non-international students on academic performance and retention rates. The conceptual…

  7. Comparative Analyses of Physics Candidates Scores in West African and National Examinations Councils

    ERIC Educational Resources Information Center

    Utibe, Uduak James; Agah, John Joseph

    2015-01-01

    The study is a comparative analysis of physics candidates' scores in West African and National Examinations Councils. It also investigates influence of gender. Results of 480 candidates were randomly selected form three randomly selected Senior Science Colleges using the WASSCE and NECOSSCE computer printout sent to the schools, transformed using…

  8. Comparing Two Examination Results Using Means of Sample Means and Control Charts

    ERIC Educational Resources Information Center

    Alabi-Labaika, A. Bisi; Ahani, E.

    2015-01-01

    Some examination candidates submit their scripts first, sometimes, for recognition as being brilliant, and some do for not knowing what to write. However, some equally submit last because they want to dot i's and cross t's. The objective of this research is to compare the results of both the earliest and latest submissions with the aim of finding…

  9. Comparing Multidimensional and Continuum Models of Vocabulary Acquisition: An Empirical Examination of the Vocabulary Knowledge Scale

    ERIC Educational Resources Information Center

    Stewart, Jeffrey; Batty, Aaron Olaf; Bovee, Nicholas

    2012-01-01

    Second language vocabulary acquisition has been modeled both as multidimensional in nature and as a continuum wherein the learner's knowledge of a word develops along a cline from recognition through production. In order to empirically examine and compare these models, the authors assess the degree to which the Vocabulary Knowledge Scale (VKS;…

  10. A Three-Phase Examination of Academic Comparative Optimism and Perceived Academic Control

    ERIC Educational Resources Information Center

    Ruthig, Joelle C.; Hanson, Bridget L.; Marino, Joanna M.

    2009-01-01

    Early academic perceptions are critical to undergraduate students' success in college. This 3-phase study examined stability of and links between academic comparative optimism (ACO; positive expectations about future performance) and perceived academic control (PAC; sense of influence over academic outcomes) among 68 undergraduate students. ACO…

  11. Similarities in STXM-NEXAFS Spectra of Atmospheric Particles and Secondary Organic Aerosol Generated from Glyoxal, α-Pinene, Isoprene, 1,2,4-Trimethylbenzene, and d-Limonene

    SciTech Connect

    Shakya, Kabindra M.; Liu, Shang; Takahama, Satoshi; Russell, Lynn M.; Keutsch, Frank N.; Galloway, Melissa M.; Shilling, John E.; Hiranuma, Naruki; Song, Chen; Kim, Hwajin; Paulson, Suazanne E.; Pfaffenberger, Lisa; Barmet, Peter; Slowik, J. G.; Prevot, A. S. H.; Dommen, J.; Baltensperger, Urs

    2013-02-06

    Functional group composition of particles produced in smog chambers are examined using scanning transmission X-ray microscopy (STXM) with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy in order to identify characteristic spectral signatures for secondary organic aerosol (SOA). Glyoxal uptake studies showed absorption for mainly alkyl, carbon-nitrogen (C-N), and carboxylic carbonyl groups. The SOA formed from the photooxidation of α-pinene (with and without isoprene) showed stronger absorptions for alkyl and carbonyl groups than the glyoxal studies. The mass ratio of carbonyl to acid group was larger in α-pinene-only experiments relative to the mixed α-pinene-isoprene experiments. The chamber particle spectra were compared with the ambient particle spectra from multiple field campaigns to understand the potential SOA sources. One hundred nineteen particles from six field campaigns had spectral features that were considered similar to the chamber-SOA particles: MILAGRO-2006 (9 particles), VOCALS-2008 (42 particles), Whistler-2008 (22 particles), Scripps Pier-2009 (9 particles), Bakersfield-2010 (25 particles), and Whistler-2010 (12 particles). These similarities with SOA formed from glyoxal, α-pinene (with and without isoprene), 1,2,4-trimethylbenzene, and limonene provide spectroscopic evidence of SOA products from these precursors in ambient particles.

  12. Double-blind comparative examination of ketoconazole 1% cream and clotrimazole 2% ointment in superficial dermatomycosis.

    PubMed

    Török, I; Stehlich, G

    1993-01-01

    Comparative examinations were performed with ketoconazole (Nizoral) 1% cream and clotrimazole (Canesten) 2% ointment in 41 patients suffering from superficial dermatomycosis. Twenty-one patients were treated with ketoconazole, twenty patients, with clotrimazole twice daily, for a maximum 4 weeks. The results of the clinical and mycological examinations showed no significant differences when comparing the two groups treated with the different products. Trichophyton rubrum was the most frequently isolated strain in both groups. Side-effect occurred in two of the patients treated with ketoconazole cream (erythema, burning sensation) which did not require the discontinuation of therapy. In the clotrimazole-treated group the therapy had to be discontinued in 3 patients because of dryness of skin, burning sensation, and aggravation of inflammatory symptoms. PMID:8278940

  13. An Analysis of the NEXAFS Spectra of a molecular crystal: alpha-Glycine

    SciTech Connect

    Schwartz, Craig P.; Saykally, Richard J.; Prendergast, David

    2010-06-18

    The nitrogen K-edge Near Edge X-ray Absorption Fine Structure (NEXAFS) spectrum of alpha-crystalline glycine has been calculated for temperatures ranging from 0 K to 450 K. Significant temperature dependent spectral changes are predicted. The calculated room temperature spectrum is in good agreement with experiment. At high temperatures, molecular motions strongly influence the spectrum, as any unique spectrum from an individual instantaneous configuration does not resemble the experimental result or the average calculated spectrum; complex coupled motions in this prototypical molecular crystal underlie the observed spectral changes.

  14. The nature of nitrate at the ice surface studied by XPS and NEXAFS.

    PubMed

    Krepelová, Adéla; Newberg, John; Huthwelker, Thomas; Bluhm, Hendrik; Ammann, Markus

    2010-08-21

    Trace contaminants such as strong acids have been suggested to affect the thickness of the quasi-liquid layer at the ice/air interface, which is at the heart of heterogeneous chemical reactions between snowpacks or cirrus clouds and the surrounding air. We used X-ray photoelectron spectroscopy (XPS) and electron yield near edge X-ray absorption fine structure (NEXAFS) spectroscopy at the Advanced Light Source (ALS) to probe the ice surface in the presence of HNO(3) formed from the heterogeneous hydrolysis of NO(2) at 230 K. We studied the nature of the adsorbed species at the ice/vapor interfaces as well as the effect of HNO(3) on the hydrogen bonding environment at the ice surface. The NEXAFS spectrum of ice with adsorbed HNO(3) can be represented as linear combination of the clean ice and nitrate solution spectrum, thus indicating that in the presence of HNO(3) the ice surface consists of a mixture of clean ice and nitrate ions that are coordinated as in a concentrated solution at the same temperature but higher HNO(3) pressures. PMID:20532376

  15. C-1s NEXAFS spectroscopy reveals chemical fractionation of humic acid by cation-induced coagulation

    SciTech Connect

    Christl,I.; Kretzschmar, R.

    2007-01-01

    The influence of cation-induced coagulation on the chemical composition of dissolved and coagulated fractions of humic acid was investigated in batch coagulation experiments for additions of aluminum at pH 4 and 5, iron at pH 4, and calcium and lead at pH 6. The partitioning of organic carbon and metals was determined by analyzing total organic carbon and total metal contents of the dissolved phase. Both the dissolved and the coagulated humic acid fractions were characterized using synchrotron scanning transmission X-ray microscopy (STXM) and C-1s near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Intensities of {pi}* transitions of carboxyl carbon and {sigma}* transitions of alkyl, O-alkyl, and carboxyl carbon decreased with increasing metal concentration for the dissolved humic acid fractions. This decrease was accompanied by an increase of the respective intensities in the coagulated fraction as shown for lead. Intensities of aromatic and phenolic carbon were affected to a larger extent only by aluminum and iron additions. The changes observed in the C-1s NEXAFS spectra coincided with an increasing removal of organic carbon from the dissolved phase with increasing total metal concentrations. We conclude that humic acid was chemically fractionated by cation-induced coagulation, which preferentially removed functional groups involved in metal-cation binding from solution.

  16. Vibrationally resolved high-resolution NEXAFS and XPS spectra of phenanthrene and coronene

    SciTech Connect

    Fronzoni, Giovanna; Baseggio, Oscar; Stener, Mauro; Hua, Weijie; Tian, Guangjun; Luo, Yi; Apicella, Barbara; Alfé, Michela; Simone, Monica de; Kivimäki, Antti; Coreno, Marcello

    2014-07-28

    We performed a combined experimental and theoretical study of the C1s Near-Edge X-ray Absorption Fine-Structure (NEXAFS) spectroscopy and X-ray Photoelectron Spectroscopy in the gas phase of two polycyclic aromatic hydrocarbons (phenanthrene and coronene), typically formed in combustion reactions. In the NEXAFS of both molecules, a double-peak structure appears in the C1s → LUMO region, which differ by less than 1 eV in transition energies. The vibronic coupling is found to play an important role in such systems. It leads to weakening of the lower-energy peak and strengthening of the higher-energy one because the 0 − n (n > 0) vibrational progressions of the lower-energy peak appear in nearly the same region of the higher-energy peak. Vibrationally resolved theoretical spectra computed within the Frank-Condon (FC) approximation and linear coupling model agree well with the high-resolution experimental results. We find that FC-active normal modes all correspond to in-plane vibrations.

  17. Detection of enthesitis in children with Enthesitis-related arthritis: dolorimeter examination compared to ultrasonography

    PubMed Central

    Weiss, Pamela F.; Chauvin, Nancy A.; Klink, Andrew J.; Localio, Russell; Feudtner, Chris; Jaramillo, Diego; Colbert, Robert A.; Sherry, David D.; Keren, Ron

    2014-01-01

    Objective To evaluate the distribution of enthesitis and accuracy of physical examination with a dolorimeter for the detection of enthesitis in children, using ultrasound (US) assessment as the reference standard. Methods We performed a prospective cross-sectional study of 30 enthesitis-related arthritis (ERA) and 30 controls subjects. The following tendon insertion sites were assessed by standardized physical examination with a dolorimeter and US: common extensor on the lateral humerus epicondyle, common flexor on the medial humerus epicondyle, quadriceps at the superior patella, patellar ligament at the inferior patella, Achilles, and plantar fascia at the calcaneus. Results Abnormal US findings were detected most commonly at the insertions of the quadriceps (30% [18 of 60 sites]), common extensor (12% [7 of 60]), and Achilles (10% [6 of 60]) tendons. The intrarater reliability of US (kappa) was 0.78 (95% confidence interval [95% CI] 0.63–0.93) and the interrater reliability was 0.81 (95% CI 0.67–0.95). Tenderness as detected by standardized dolorimeter exam had poor positive predictive value for US-confirmed enthesitis. In comparison to controls, ERA patients reported more pain and had lower pain thresholds at every site, including control sites (P <0.01 for all comparisons). The interrater reliability of dolorimeter exam for detection of enthesitis was low (κ = 0.49 [95% CI 0.33–0.65]). Conclusions Compared to US, standardized dolorimeter examination for the detection of enthesitis in children has poor accuracy and reliability. The decreased pain threshold of ERA patients likely contributed to the limited accuracy of physical examination. Future research regarding the utility of US for identifying enthesitis at JIA diagnosis, accurately predicting disease progression, and guiding therapeutic decisions is warranted. PMID:24449586

  18. Probing the Orientation of Surface-Immobilized Protein G B1 Using ToF-SIMS Sum Frequency Generation and NEXAFS Spectroscopy

    SciTech Connect

    L Baugh; T Weidner; J Baio; P Nguyen; L Gamble; P Stayton; D Castner

    2011-12-31

    The ability to orient active proteins on surfaces is a critical aspect of many medical technologies. An important related challenge is characterizing protein orientation in these surface films. This study uses a combination of time-of-flight secondary ion mass spectrometry (ToF-SIMS), sum frequency generation (SFG) vibrational spectroscopy, and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to characterize the orientation of surface-immobilized Protein G B1, a rigid 6 kDa domain that binds the Fc fragment of IgG. Two Protein G B1 variants with a single cysteine introduced at either end were immobilized via the cysteine thiol onto maleimide-oligo(ethylene glycol)-functionalized gold and bare gold substrates. X-ray photoelectron spectroscopy was used to measure the amount of immobilized protein, and ToF-SIMS was used to measure the amino acid composition of the exposed surface of the protein films and to confirm covalent attachment of protein thiol to the substrate maleimide groups. SFG and NEXAFS were used to characterize the ordering and orientation of peptide or side chain bonds. On both substrates and for both cysteine positions, ToF-SIMS data showed enrichment of mass peaks from amino acids located at the end of the protein opposite to the cysteine surface position as compared with nonspecifically immobilized protein, indicating end-on protein orientations. Orientation on the maleimide substrate was enhanced by increasing pH (7.0-9.5) and salt concentration (0-1.5 M NaCl). SFG spectral peaks characteristic of ordered {alpha}-helix and {beta}-sheet elements were observed for both variants but not for cysteine-free wild type protein on the maleimide surface. The phase of the {alpha}-helix and {beta}-sheet peaks indicated a predominantly upright orientation for both variants, consistent with an end-on protein binding configuration. Polarization dependence of the NEXAFS signal from the N 1s to {pi}* transition of {beta}-sheet peptide bonds also

  19. C K-edge NEXAFS spectra of graphene with physical and chemical defects: a study based on density functional theory.

    PubMed

    Ehlert, Christopher; Unger, Wolfgang E S; Saalfrank, Peter

    2014-07-21

    Recently, C K-edge Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra of graphite (HOPG) surfaces have been measured for the pristine material, and for HOPG treated with either bromine or krypton plasmas (Lippitz et al., Surf. Sci., 2013, 611, L1). Changes of the NEXAFS spectra characteristic for physical (krypton) and/or chemical/physical modifications of the surface (bromine) upon plasma treatment were observed. Their molecular origin, however, remained elusive. In this work we study by density functional theory, the effects of selected point and line defects as well as chemical modifications on NEXAFS carbon K-edge spectra of single graphene layers. For Br-treated surfaces, also Br 3d X-ray Photoelectron Spectra (XPS) are simulated by a cluster approach, to identify possible chemical modifications. We observe that some of the defects related to plasma treatment lead to characteristic changes of NEXAFS spectra, similar to those in experiment. Theory provides possible microscopic origins for these changes. PMID:24901898

  20. Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy for mapping nano-scale distribution of organic carbon forms in soil: Application to black carbon particles

    NASA Astrophysics Data System (ADS)

    Lehmann, Johannes; Liang, Biqing; Solomon, Dawit; Lerotic, Mirna; LuizãO, Flavio; Kinyangi, James; SchäFer, Thorsten; Wirick, Sue; Jacobsen, Chris

    2005-03-01

    Small-scale heterogeneity of organic carbon (C) forms in soils is poorly quantified since appropriate analytical techniques were not available up to now. Specifically, tools for the identification of functional groups on the surface of micrometer-sized black C particles were not available up to now. Scanning Transmission X-ray Microscopy (STXM) using synchrotron radiation was used in conjunction with Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy to investigate nano-scale distribution (50-nm resolution) of C forms in black C particles and compared to synchrotron-based FTIR spectroscopy. A new embedding technique was developed that did not build on a C-based embedding medium and did not pose the risk of heat damage to the sample. Elemental sulfur (S) was melted to 220°C until it polymerized and quenched with liquid N2 to obtain a very viscous plastic S in which the black C could be embedded until it hardened to a noncrystalline state and was ultrasectioned. Principal component and cluster analysis followed by singular value decomposition was able to resolve distinct areas in a black carbon particle. The core of the studied biomass-derived black C particles was highly aromatic even after thousands of years of exposure in soil and resembled the spectral characteristics of fresh charcoal. Surrounding this core and on the surface of the black C particle, however, much larger proportions of carboxylic and phenolic C forms were identified that were spatially and structurally distinct from the core of the particle. Cluster analysis provided evidence for both oxidation of the black C particle itself as well as adsorption of non-black C. NEXAFS spectroscopy has great potential to allow new insight into black C properties with important implications for biogeochemical cycles such as mineralization of black C in soils and sediments, and adsorption of C, nutrients, and pollutants as well as transport in the geosphere, hydrosphere, and atmosphere.

  1. Comparative Examination of Plasmoid Ejection at Mercury, Earth, Jupiter, and Saturn

    NASA Technical Reports Server (NTRS)

    Slavin, James A.; Jackman, Caitriona M.; Vogt, Marissa F.

    2011-01-01

    The onset of magnetic reconnection in the near-tail of Earth, long known to herald the fast magnetospheric convection that leads to geomagnetic storms and substorms, is very closely associated with the formation and down-tail ejection of magnetic loops or flux ropes called plasmoids. Plasmoids form as a result of the fragmentation of preexisting cross-tail current sheet as a result of magnetic reconnection. Depending upon the number, location, and intensity of the individual reconnection X-lines and how they evolve, some of these loop-like or helical magnetic structures may also be carried sunward. At the inner edge of the tail they are expected to "re-reconnect' with the planetary magnetic field and dissipate. Plasmoid ejection has now been observed in the magnetotails of Mercury, Earth, Jupiter, and Saturn. These magnetic field and charged particle measurements have been taken by the MESSENGER, Voyager, Galileo, Cassini, and numerous Earth missions. Here we present a comparative examination of the structure and dynamics of plasmoids observed in the magnetotails of these 5 planets. The results are used to learn more about how these magnetic structures form and to assess similarities and differences in the nature of magnetotail reconnection at these planets.

  2. Examining the architecture of cellular computing through a comparative study with a computer.

    PubMed

    Wang, Degeng; Gribskov, Michael

    2005-06-22

    The computer and the cell both use information embedded in simple coding, the binary software code and the quadruple genomic code, respectively, to support system operations. A comparative examination of their system architecture as well as their information storage and utilization schemes is performed. On top of the code, both systems display a modular, multi-layered architecture, which, in the case of a computer, arises from human engineering efforts through a combination of hardware implementation and software abstraction. Using the computer as a reference system, a simplistic mapping of the architectural components between the two is easily detected. This comparison also reveals that a cell abolishes the software-hardware barrier through genomic encoding for the constituents of the biochemical network, a cell's "hardware" equivalent to the computer central processing unit (CPU). The information loading (gene expression) process acts as a major determinant of the encoded constituent's abundance, which, in turn, often determines the "bandwidth" of a biochemical pathway. Cellular processes are implemented in biochemical pathways in parallel manners. In a computer, on the other hand, the software provides only instructions and data for the CPU. A process represents just sequentially ordered actions by the CPU and only virtual parallelism can be implemented through CPU time-sharing. Whereas process management in a computer may simply mean job scheduling, coordinating pathway bandwidth through the gene expression machinery represents a major process management scheme in a cell. In summary, a cell can be viewed as a super-parallel computer, which computes through controlled hardware composition. While we have, at best, a very fragmented understanding of cellular operation, we have a thorough understanding of the computer throughout the engineering process. The potential utilization of this knowledge to the benefit of systems biology is discussed. PMID:16849179

  3. A comparative study of nucleation parameterizations: 1. Examination and evaluation of the formulations

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; McMurry, Peter H.; Yu, Fangqun; Jacobson, Mark Z.

    2010-10-01

    Large uncertainty exists in the nucleation parameterizations that may be propagated into climate change predictions through affecting aerosol direct and indirect effects. These parameterizations are derived either empirically from laboratory/field measurements or from theoretical models for nucleation rates. A total of 12 nucleation parameterizations (7 binary, 3 ternary, and 2 power laws) that are currently used in three-dimensional air quality models are examined comparatively under a variety of atmospheric conditions from polluted surface to very clean mesosphere environments and evaluated using observations from several laboratory experiments and a field campaign conducted in a sulfate-rich urban environment in the southeastern United States (i.e., Atlanta, Georgia). Significant differences (by up to 18 orders of magnitude) are found among the nucleation rates calculated with different parameterizations under the same meteorological and chemical conditions. All parameterizations give nucleation rates that increase with the number concentrations of sulfuric acid but differ in terms of the magnitude of such increases. Differences exist in their dependencies on temperatures, relative humidity, and the mixing ratios of ammonia in terms of both trends and magnitudes. Among the 12 parameterizations tested, the parameterizations of Kuang et al. (2008), Sihto et al. (2006), and Harrington and Kreidenweis (1998) give the best agreement with the observed nucleation rates in most laboratory studies and in Atlanta during a summer season field campaign and either do not exceed or rarely exceed the upper limits of the nucleation rates (i.e., the dimer formation rate) and new particle formation rates (i.e., the formation rate of particles with 2 nm diameter). They are thus the most plausible nucleation parameterizations for applications in the planetary boundary layer of polluted sulfate-rich urban areas. Limitation with the two power laws are that they were derived

  4. Comparative College Examinations: More Gain, Less Pain When Students Share Information and Grades.

    ERIC Educational Resources Information Center

    Zimbardo, Phillip G.; Butler, Lisa D.; Wolfe, Valerie A.

    2003-01-01

    Examination performance of introductory psychology students (n=576) was significantly enhanced in each of 4 separate comparisons of those taking tests with a partner versus traditional solo testing. Found positive effects in both assigned and freely chosen teams. (SLD)

  5. Characterization of microscale wear in a ploysilicon-based MEMS device using AFM and PEEM-NEXAFS spectromicroscopy.

    SciTech Connect

    Grierson, D. S.; Konicek, A. R.; Wabiszewski, G. E.; Sumant, A. V.; de Boer, M. P.; Corwin, A. D.; Carpick, R. W.

    2009-12-01

    Mechanisms of microscale wear in silicon-based microelectromechanical systems (MEMS) are elucidated by studying a polysilicon nanotractor, a device specifically designed to conduct friction and wear tests under controlled conditions. Photoelectron emission microscopy (PEEM) was combined with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and atomic force microscopy (AFM) to quantitatively probe chemical changes and structural modification, respectively, in the wear track of the nanotractor. The ability of PEEM-NEXAFS to spatially map chemical variations in the near-surface region of samples at high lateral spatial resolution is unparalleled and therefore ideally suited for this study. The results show that it is possible to detect microscopic chemical changes using PEEM-NEXAFS, specifically, oxidation at the sliding interface of a MEMS device. We observe that wear induces oxidation of the polysilicon at the immediate contact interface, and the spectra are consistent with those from amorphous SiO{sub 2}. The oxidation is correlated with gouging and debris build-up in the wear track, as measured by AFM and scanning electron microscopy (SEM).

  6. Examining the Legitimacy of Unrecognised Low-Fee Private Schools in India: Comparing Different Perspectives

    ERIC Educational Resources Information Center

    Ohara, Yuki

    2012-01-01

    Studies to date show how low-fee private (LFP) schools, including unrecognised ones, have gained practical legitimacy and continue to increase in number. However, little explanation is offered regarding the legal legitimacy of such unrecognised LFP schools. This paper intends to fill this gap by examining the legal legitimacy of unrecognised…

  7. Examining Metacognition in Hearing and Deaf/Hard of Hearing Students: A Comparative Study.

    ERIC Educational Resources Information Center

    Al-Hilawani, Yasser A.

    2001-01-01

    The metacognitive performance of 87 Arab typically developing adolescents and 20 Arab adolescents with deafness was examined. There was no significant difference between the students in metacognitive performance, nor were there gender-based differences among students with deafness. However, hearing female students scored significantly higher on…

  8. Examining Perspectives of Entry-Level Teacher Candidates: A Comparative Study

    ERIC Educational Resources Information Center

    Liu, Ping

    2010-01-01

    This study examines entry-level teacher candidates on career choice, professional goals and view on a teacher's role. The candidates were enrolled in two elementary teacher education programs in the People's Republic of China and the United States of America. A total of 66 participants responded in writing to three questions about why they decided…

  9. Typing Compared with Handwriting for Essay Examinations at University: Letting the Students Choose

    ERIC Educational Resources Information Center

    Mogey, Nora; Paterson, Jessie; Burk, John; Purcell, Michael

    2010-01-01

    Students at the University of Edinburgh do almost all their work on computers, but at the end of the semester they are examined by handwritten essays. Intuitively it would be appealing to allow students the choice of handwriting or typing, but this raises a concern that perhaps this might not be "fair"--that the choice a student makes, to write or…

  10. Examining a Classwide Application of Cover-Copy-Compare with and without Goal Setting to Enhance Mathematics Fluency

    ERIC Educational Resources Information Center

    Codding, Robin S.; Chan-Iannetta, Lisa; Palmer, Molley; Lukito, Grace

    2009-01-01

    The purpose of this study was to compare the effects of cover-copy-compare alone and combined with two forms of goal setting to a control condition on the mathematics fluency of 173 third-grade students. Treatment sessions occurred twice weekly for a total of 6 weeks, and multilevel modeling was used to examine progress across intervention…

  11. Plasma bromination of HOPG surfaces: A NEXAFS and synchrotron XPS study

    NASA Astrophysics Data System (ADS)

    Lippitz, Andreas; Friedrich, Jörg F.; Unger, Wolfgang E. S.

    2013-05-01

    Br bonding on plasma brominated graphite surfaces has been studied by using Near Edge X-ray Absorption Fine Structure (NEXAFS) and X-ray Photoelectron Spectroscopy (XPS). Br2 and bromoform were used as plasma gases in an r.f. cw low pressure plasma process. Kr plasma had been used to study separately the physical and chemical plasma etching effects. At early steps of plasma bromination which lead to only small XPS Br surface concentration values a quick decay of aromaticity has been observed. At low Br surface concentration radical or even electrophilic addition of bromine onto sp2 carbon atoms is discussed as the dominating reaction pathway. At higher Br surface concentrations the inherent formation of sp3 defects in the graphene network by chemical etching processes promotes nucleophilic substitution of bromine at sp3 carbons as a competing reaction pathway. Both reaction pathways lead to C-Br species characterized by the same Br 3d XPS binding energy. However more than one Br 3d component in XP spectra has been found at lower Br2 plasma induced Br surface concentrations and complexation of bromine at HOPG is assumed as a third way of interaction with Br2 plasma.

  12. Nuclear quantum effects in the structure and lineshapes of the N2 NEXAFS spectrum

    SciTech Connect

    Fatehi, Shervin; Schwartz, Craig P.; Saykally, Richard J.; Prendergast, David

    2009-12-04

    We study the relative ability of several models of the X-ray absorption spectrum to capture the Franck-Condon structure apparent from an experiment on gaseous nitrogen. In doing so, we adopt the Born-Oppenheimer approximation and a constrained density functional theory method for computing the energies of the X-ray-excited molecule. Starting from an otherwise classical model for the spectrum, we systematically introduce more realistic physics, first by substituting the quantum mechanical nuclear radial density in the bond separation R for the classical radial density, then by adding the effect of zero-point energy and other level shifts, and finally by including explicit rovibrational quantization of both the ground and excited states. The quantization is determined exactly, using a discrete variable representation. We show that the NEXAFS spectrum can be predicted semiquantiatively within this framework. We also address the possibility of non-trivial temperature dependence in the spectrum. Finally, we show that it is possible to improve the predicted spectrum by using constrained DFT in combination with more accurate potentials.

  13. Mathematics Teachers' Didactic Strategies: Examining the Comparative Potential of Low Inference Generic Descriptors

    ERIC Educational Resources Information Center

    Andrews, Paul

    2009-01-01

    An increasingly common approach to comparative education research, particularly with respect to mathematics education, has been the exploitation of video technology, not least because the use of video cameras offers several advantages over traditional methods such as direct observation. It is important to acknowledge, however, that video…

  14. Examining metacognition in hearing and deaf/hard of hearing students: a comparative study.

    PubMed

    al-Hilawani, Y A

    2001-03-01

    The metacognitive performance of 87 hearing and 20 deaf/hard of hearing students was examined. The hearing students consisted of 42 males (mean age 15.6 years) and 45 females (mean age 15.4 years). The deaf/hard of hearing students consisted of 13 males (mean age 16.9 years) and 7 females (mean age 15.9 years). Metacognition was conceptualized in terms of choosing the best response to problematic situations drawing upon problem-solving and logical reasoning skills. In the test, pictures represented various daily life interactions. There was no significant difference between hearing and deaf/hard of hearing students in metacognitive performance, nor was there a gender-based significant difference among the deaf/hard of hearing students. However, hearing female students scored significantly higher on the metacognitive test than hearing male students. Further analysis of the study findings possibly would show students' overall performance on the metacognitive test to be independent of grade point average. Analysis did show, however, a significant negative correlation between test performance and grades in Arabic among deaf/hard of hearing students. PMID:11355077

  15. Skin Self-Examinations and Visual Identification of Atypical Nevi: Comparing Individual and Crowdsourcing Approaches

    PubMed Central

    King, Andy J.; Gehl, Robert; Grossman, Douglas; Jensen, Jakob D.

    2013-01-01

    Purpose Skin self-examination (SSE) is one method for identifying atypical nevi among members of the general public. Unfortunately, past research has shown that SSE has low sensitivity in detecting atypical nevi. The current study investigates whether crowdsourcing (collective effort) can improve SSE identification accuracy. Collective effort is potentially useful for improving people’s visual identification of atypical nevi during SSE because, even when a single person has low reliability at a task, the pattern of the group can overcome the limitations of each individual. Methods Adults (N = 500) were recruited from a shopping mall in the Midwest. Participants viewed educational pamphlets about SSE and then completed a mole identification task. For the task, participants were asked to circle mole images that appeared atypical. Forty nevi images were provided; nine of the images were of nevi that were later diagnosed as melanoma. Results Consistent with past research, individual effort exhibited modest sensitivity (.58) for identifying atypical nevi in the mole identification task. As predicted, collective effort overcame the limitations of individual effort. Specifically, a 19% collective effort identification threshold exhibited superior sensitivity (.90). Conclusions The results of the current study suggest that limitations of SSE can be countered by collective effort, a finding that supports the pursuit of interventions promoting early melanoma detection that contain crowdsourcing visual identification components. PMID:24075797

  16. A Comparative Examination of two Fmoc Removal Reagents for Process Improvement to Produce Peptide Drugs

    NASA Astrophysics Data System (ADS)

    Srivastava, K.; Davis, M.

    The importance of peptides as therapeutics has been recognized since they were found responsible for a wide variety of biological functions. The recent approval of peptide drugs such as Byetta® (Amylin Pharmaceuticals, Inc.), Fuzeon® (Hoffman-LaRoche Inc.), Integrelin™ (CDR Therapeutics, Inc.), Natrecor® (SCIOS Inc.), Symlin® (Amylin), Teriparatide, and Ziconotide, etc., which demonstrated applications for treatment of such problems as bone metabolism disorders, cardiovascular diseases, diabetes, viral infections and severe chronic pain control, has further endorsed the growing interest in peptides as a potential drug. This growing trend for peptide drugs has drawn our attention for their production in a cost-effective manner. To do so, the improvement in the quality of crude peptides during synthesis, the most critical parameter in the process, is important to prevent yield losses during the more expensive purification step. To accomplish it, we decided to examine the efficacy of the commonly used nucleophilic base piperidine and non-neucleophilic base DBU (1,8-Diazabicyclo[5.4.0]undec-7-ene) for the complete removal of Fmoc group during the synthesis of peptides. According to our investigation, application of piperidine was found more effective than DBU in solid phase synthesis. Details of the investigation will be discussed.

  17. Comparative Examination of Reconnection-Driven Magnetotail Dynamics at Mercury and Earth

    NASA Astrophysics Data System (ADS)

    Slavin, J. A.

    2014-12-01

    MESSENGER plasma and magnetic field observations of Mercury's magnetotail are reviewed and compared to that of Earth. Mercury's magnetosphere is created by the solar wind interaction with its highly dipolar, spin-axis aligned magnetic field. However, its equatorial magnetic field is ~ 150 times weaker than at Earth. As a result the altitude of its subsolar magnetopause is typically only ~ 1000 km and there is no possibility for trapped radiation belts. Magnetopause reconnection at Mercury does not exhibit the "half-wave rectifier" response to interplanetary magnetic field (IMF) direction observed at Earth. Rather magnetopause reconnection occurs for all non-zero shear angles with plasma β as the primary parameter controlling its rate. The cross-magnetosphere electric potential drop derived from magnetopause and plasma mantle structure is ~ 30 kV in contrast to ~ 100 kV at Earth. This large potential drop at Mercury relative to its small size appears due to the lack of an electrically conducting ionosphere and the strong IMF found in the inner heliosphere. Structurally these magnetotails are very similar in most respects, but the magnetic field intensities and plasma densities and temperatures are all higher at Mercury. Plasma sheet composition indicates solar wind origin, but with 10% Na+ derived from it tenuous exosphere. Given Mercury's very slow rotation rate, once every 59 Earth days, most sunward plasma sheet convection will impact the nightside of the planet. Magnetic flux loading/unloading in Mercury's tail is similar to that seen at Earth during substorms. However, the duration and amplitude of these cycles are ~ 2 - 3 min and ~ 30 to 50 %, respectively, as compared to ~ 1 - 2 hr and 10 - 25 % at Earth. These episodic, substorm-like events are accompanied by plasmoid ejection and near-tail dipolarization similar what is seen at Earth. Mercury can also exhibit Earth-like steady magnetospheric convection during which plasmoid ejection and dipolarization

  18. A Comparative Examination of Plasmoid Structure and Dynamics at Mercury, Earth, Jupiter, and Saturn

    NASA Technical Reports Server (NTRS)

    Slavin, James A.

    2010-01-01

    The circulation of plasma and magnetic flux within planetary magnetospheres is governed by the solar wind-driven Dungey and planetary rotation-driven cycles. The Dungey cycle is responsible for all circulation at Mercury and Earth. Jupiter and Saturn's magnetospheres are dominated by the Vasyliunas cycle, but there is evidence for a small Dungey cycle contribution driven by the solar wind. Despite these fundamental differences, all well-observed magnetospheres eject relatively large parcels of the hot plasma, termed plasmoids, down their tails at high speeds. Plasmoids escape from the restraining force of the planetary magnetic field through reconnection in the equatorial current sheet separating the northern and southern hemispheres of the magnetosphere. The reconnection process gives the magnetic field threading plasmoids a helical or flux rope-type topology. In the Dungey cycle reconnection also provides the primary tailward force that accelerates plasmoids to high speeds as they move down the tail. We compare the available observations of plasmoids at Mercury, Earth, Jupiter, and Saturn for the purpose of determining the relative role of plasmoids and the reconnection process in the dynamics these planetary magnetic tails.

  19. Processing of atmospheric particles caught in the act via STXM/NEXAFS

    NASA Astrophysics Data System (ADS)

    Steimer, S.; Lampimäki, M.; Grzinic, G.; Coz, E.; Watts, B.; Raabe, J.; Ammann, M.

    2012-12-01

    Atmospheric aerosols are an important focus of environmental research due to their effect on climate and human health. Among their main constituents are mineral dust and organic particles. Both types of particles directly and indirectly affect our climate through scattering and absorption of radiation and through acting as cloud condensation nuclei respectively. Organic particles are also of significant concern with respect to their health effects. Mineral dust particles in addition serve as a primary external iron source to the open ocean and the bioavailability of iron from these particles is highly dependent on the oxidation state of the metal. The environmental impact of atmospheric particles depends on their physical and chemical properties, which might change upon chemical ageing. In this study we therefore investigated the changes in chemical composition and morphology of mineral dust and organic particle proxies (Arizona test dust and shikimic acid, respectively) upon in situ exposure to ozone or nitrogen oxides in presence of humidity. This was achieved by monitoring changes at the C and O K-edges as well as the metal L-edges via scanning transmission X-ray microscopy (STXM) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Measurements were conducted at the PolLux beamline at Swiss Light Source. All experiments were conducted in an environmental micro reactor, designed specifically for the end station, to enable the investigation in situ. We observed oxidation of shikimic acid particles in situ during exposure to ozone at different humidities, whereby humidity was found to be a critical factor controlling the rate of the reaction. We also obtained well resolved iron distribution maps from the individual submicrometer size mineral dust particles before and after exposure to nitrogen oxides.

  20. Examination of a Physical Education Personal Health Science Course: Face-to-Face Classroom Compared to Online Hybrid Instruction

    ERIC Educational Resources Information Center

    Frimming, Renee Elizabeth; Bower, Glenna G.; Choi, Chulhwan

    2013-01-01

    Many studies have compared traditional face-to-face courses to online or distance education courses. The purpose of this study was to examine academic performance, perceptions, and experiences of participants enrolled in different academic learning environments. Pre and Post Content Knowledge Tests and a student evaluation were used to measure…

  1. A Comparative Cross-Cultural Examination of Community Art Education Programs in South Korea and the United States

    ERIC Educational Resources Information Center

    Shin, Ryan; Kim, Junghee

    2014-01-01

    The authors conducted comparative cross-cultural research to examine a select group of the available and more noteworthy art education organizations and their programs after observing significant differences in the community art education programs offered in Tucson, Arizona, and Anyang, South Korea. The study reports several major differences…

  2. Testicular biopsy in psittacine birds (Psittaciformes): comparative evaluation of testicular reproductive status by endoscopic, histologic, and cytologic examination.

    PubMed

    Hänse, Maria; Krautwald-Junghanns, Maria-Elisabeth; Reitemeier, Susanne; Einspanier, Almuth; Schmidt, Volker

    2013-12-01

    Knowledge of the reproductive cycle of male parrots is important for examining the male genital tract and for successful breeding, especially of endangered species. To evaluate different diagnostic methods and criteria concerning the classification of reproductive stages, we examined 20 testicular samples obtained at necropsy in psittacine birds of different species and testicular biopsy samples collected from 9 cockatiels (Nymphicus hollandicus) and 7 rose-ringed parakeets (Psittacula krameri) by endoscopy 4 times over a 12-month period. The testicular reproductive status was assessed histologically and then compared with the macroscopic appearance of the testicles and cytologic results. The histologic examination was nondiagnostic in 19 of 59 testicular biopsy samples. By contrast, the cytologic preparations were diagnostic in 57 of 59 biopsy samples. The results of the cytologic examination coincided with the histologic results in 34 of 38 biopsy samples and 18 of 20 necropsy samples. Macroscopic parameters displayed some differences between reproductive stages but provided an unreliable indication of the reproductive status. These results suggest that microscopic examination of a testicular biopsy sample is a reliable method for evaluating the reproductive status of male parrots and is preferable to the macroscopic evaluation of the testicle. Cytologic examination provides fast preliminary results, even when the histologic preparation is not sufficient for evaluation, but results may be erroneous. Thus, a combination of histologic and cytologic examination is recommended for evaluating testicular reproductive status. PMID:24640925

  3. Comparative assessment of three image reconstruction techniques for image quality and radiation dose in patients undergoing abdominopelvic multidetector CT examinations

    PubMed Central

    Desai, G S; Thabet, A; Elias, A Y A; Sahani, D V

    2013-01-01

    Objective To compare image quality and radiation dose of abdominal CT examinations reconstructed with three image reconstruction techniques. Methods In this Institutional Review Board-approved study, contrast-enhanced (CE) abdominopelvic CT scans from 23 patients were reconstructed using filtered back projection (FBP), adaptive statistical iterative reconstruction (ASiR) and iterative reconstruction in image space (IRIS) and were reviewed by two blinded readers. Subjective (acceptability, sharpness, noise and artefacts) and objective (noise) measures of image quality were recorded for each image data set. Radiation doses in CT dose index (CTDI) dose–length product were also calculated for each examination type and compared. Imaging parameters were compared using the Wilcoxon signed rank test and a paired t-test. Results All 69 CECT examinations were of diagnostic quality and similar for overall acceptability (mean grade for ASiR, 3.9±0.3; p=0.2 for Readers 1 and 2; IRIS, 3.9±0.4, p=0.2; FBP, 3.8±0.9). Objective noise was considerably lower with both iterative techniques (p<0.0001 and 0.0016 for ASiR and IRIS). Recorded mean radiation dose, i.e. CTDIvol, was 24% and 10% less with ASiR (11.4±3.4 mGy; p<0.001) and IRIS (13.5±3.7 mGy; p=0.06), respectively, than with FBP: 15.0±3.5 mGy. Conclusion At the system parameters used in this study, abdominal CT scans reconstructed with ASiR and IRIS provide diagnostic images with reduced image noise and 10–24% lower radiation dose than FBP. Advances in knowledge CT images reconstructed with FBP are frequently noisy on lowering the radiation dose. Newer iterative reconstruction techniques have different approaches to produce images with less noise; ASiR and IRIS provide diagnostic abdominal CT images with reduced image noise and radiation dose compared with FBP. This has been documented in this study. PMID:23255538

  4. NEXAFS spectroscopy and site-specific fragmentation of N-methylformamide, N,N-dimethylformamide, and N,N-dimethylacetamide

    NASA Astrophysics Data System (ADS)

    Salén, Peter; Yatsyna, Vasyl; Schio, Luca; Feifel, Raimund; Richter, Robert; Alagia, Michele; Stranges, Stefano; Zhaunerchyk, Vitali

    2016-06-01

    Near-edge X-ray absorption fine-structure (NEXAFS) spectra measured at the C, N, and O K-edges for three molecules containing the amide moiety, N-methylformamide (HCONHCH3), N,N-dimethylformamide (HCON(CH3)2), and N,N-dimethylacetamide (CH3CON(CH3)2) are presented. These molecules have similar structures and differ by the number of methyl groups located at the molecular ends. The fragmentation of these molecules after resonant excitation at different K-edge resonances is also investigated, using a 3D-ion imaging time-of-flight spectrometer. A comparison between the molecules with respect to the relative contributions of the fragments created upon excitation at distinct resonances reveals site-specific fragmentation. Further information about the character of the core-excitation and dissociation process is obtained from the angular distributions of the ion fragments.

  5. Nanoscale Biogeocomplexity of the Organomineral Assemblage in Soil: Application of STXM Microscopy and C 1s-NEXAFS Spectroscopy

    SciTech Connect

    Kinyangi,J.; Solomon, D.; Liang, B.; Lerotic, M.; Wirick, S.; Lehmann, J.

    2006-01-01

    Methodological constraints limit the extent to which existing soil aggregation models explain carbon (C) stabilization in soil. We hypothesize that the physical infrastructure of microaggregates plays a major role in determining the chemistry of the occluded C and intimate associations between particulate C, chemically stabilized C and the soil mineral matrix. We employed synchrotron-based scanning transmission X-ray microscopy (STXM) coupled with near-edge X-ray absorption fine structure (C 1s-NEXAFS) spectroscopy to investigate the nanoscale physical assemblage and C chemistry of 150-{micro}m microaggregates from a Kenyan Oxisol. Ultra-thin sections were obtained after embedding microaggregates in a sulfur block and sectioning on a cryo-microtome at -55 degrees C. Principal component and cluster analyses revealed four spatially distinct features: pore surfaces, mineral matter, organic matter, and their mixtures. The occurrence of these features did not vary between exterior and interior locations; however, the degree of oxidation decreased while the complexity and occurrence of aliphatic C forms increased from exterior to interior regions of the microaggregate. At both locations, compositional mapping rendered a nanoscale distribution of oxidized C clogging pores and coating pore cavities on mineral surface. Hydrophobic organic matter of aromatic and aliphatic nature, representing particulate C forms appeared physically occluded in 2- to 5-{micro}m pore spaces. Our findings demonstrate that organic matter in microaggregates may be found as either oxidized C associated with mineral surfaces or aromatic and aliphatic C in particulate form. Using STXM and C 1s-NEXAFS we are for the first time able to resolve the nanoscale biogeocomplexity of unaltered soil microaggregates.

  6. The Eating Disorders Examination in Adolescent Males with Anorexia Nervosa: How Does It Compare to Adolescent Females?

    PubMed Central

    Darcy, Alison M.; Doyle, Angela Celio; Lock, James; Peebles, Rebecka; Doyle, Peter; Le Grange, Daniel

    2010-01-01

    Objective The study aimed to explore the Eating Disorder Examination (EDE) for adolescent males with eating disorders (EDs) compared with adolescent females with EDs. Method Data were collected from 48 males and matched on percent median body weight (MBW) and age to 48 females at two sites. Results Adolescent males with anorexia nervosa-type presentation scored significantly lower than matched females on Shape Concern, Weight Concern, and Global score. They also scored lower on a number of individual items. Discussion The EDE has clinical utility with adolescent males with anorexic-type presentation although males’ scoring ranges are consistently lower than those from adolescent females with similar clinical presentations. Males scored significantly lower on a number of items representing core symptoms such as desire to lose weight. More research is needed to gain a better understanding of the experience of adolescent males with EDs, particularly in relation to the nature of shape concern. PMID:22170022

  7. Metal-ion Complexation Effects in C 1s-NEXAFS Spectra of Carboxylic Acids—Evidence by Quantum Chemical Calculations

    SciTech Connect

    Armbruster, M.; Schimmelpfennig, B; Plaschke, M; Rothe, J; Denecke, M; Klenze, R

    2009-01-01

    Previous systematic C 1s-NEXAFS studies carried out for humic acid (HA) loaded with polyvalent metal cations (Mn+) reveal spectral features which were postulated to result from metal ion complexation: a strong decrease of the C 1s (COO-) ? p*Cdouble bond; length as m-dashO transition intensity and the appearance of a new absorption feature at slightly lower energy adjacent to the carboxyl resonance. Although spectroscopic results for the Mn+-PAA (polyacrylic acid) system (selected as model for structurally ill-defined HA) reveal the same spectral features, evidence by an independent approach for interpretation of these features is desirable. It is well established that quantum chemical calculations are capable of reproducing transition features in C 1s core excitation spectra of small organic molecules, e.g., acetate, which is chosen here as a fragment containing the complexing group to model the macromolecular HA and PAA systems. In this study, the RI-ADC(2) approach, as implemented in the TURBOMOLE program package, is applied to calculate vertical core excitation spectra of various metal acetates and the acetate anion. An energy shift (?f) between the C 1s (COO-) ? p*Cdouble bond; length as m-dashO transition of the acetate anion and various metal cation acetates is established. Calculated shifts are very similar to the experimentally observed values for the energy difference between the C 1s (COO-) ? p*Cdouble bond; length as m-dashO peak and the absorption feature appearing after metal ion complexation in Mn+-PAA/PAA. According to our computations, structural changes of the acetate complexes (e.g., the O-CeO bond angle) compared to the free acetate anion are predominantly responsible for the spectral changes observed upon metal ion complexation.

  8. An experimental NEXAFS and computational TDDFT and ΔDFT study of the gas-phase core excitation spectra of nitroxide free radical TEMPO and its analogues.

    PubMed

    Ljubić, Ivan; Kivimäki, Antti; Coreno, Marcello

    2016-04-21

    Core-hole spectroscopy adds to the fundamental understanding of the electronic structure of stable nitroxide free radicals thus paving way for a sensible design of new analogues with desired functionalities. We study the gas-phase C 1s, N 1s and O 1s excitation spectra of three nitroxide free radicals - TEMPO and two of its amide-substituted analogues - using the experimental NEXAFS technique and the theoretical TDDFT and ΔDFT methods in the unrestricted setting. The short-range corrected SRC1-BLYP and SRC2-BLYP exchange-correlation functionals are used with TDDFT, and the standard B3LYP functional with ΔDFT. The TDDFT-based detailed spectral assignment includes the valence, mixed valence-Rydberg and Rydberg portions of the spectra from the onset of absorptions to the vicinity of the core-ionization thresholds. The relative overlaps between the experimental and TDDFT-modelled spectra are reasonably good, in the range of 0.7-0.8, 0.6-0.8, and 0.7-0.8 for the C 1s, N 1s, and O 1s spectra, respectively. The extent of spin contamination within the unrestricted framework and its effect on the accuracy of the calculated excitation energies and dipole intensities are discussed in detail. It is concluded that, despite the sizeable spin contamination, the presently used methods are capable of predicting the core-excitation spectra of comparatively large free radical species fairly reliably over a wide spectral range. PMID:27020039

  9. Nature of the empty states and signature of the charge density wave instability and upper Peierls transition of TTF-TCNQ by temperature-dependent NEXAFS spectroscopy

    NASA Astrophysics Data System (ADS)

    Chernenkaya, Alisa; Medjanik, Katerina; Nagel, Peter; Merz, Michael; Schuppler, Stefan; Canadell, Enric; Pouget, Jean-Paul; Schönhense, Gerd

    2015-01-01

    The electronic structure of TTF-TCNQ was studied by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy in order to detect a spectroscopic signature of the phase transitions, especially that occurring at 54 K, which is related to a Peierls gap opening on the TCNQ stacks. All unoccupied TCNQ orbitals predicted by first-principles calculations and, in particular the pair σ ∗( π( a g , b 3 u )), located in the cyano groups, are clearly resolved in our experimental data. The latter orbital was observed for the first time in our NEXAFS spectra. The temperature dependence of NEXAFS peak intensities gives evidence of a subtle modification of the electronic structure when the charge density wave (CDW) fluctuations develop as the Peierls transition of the TCNQ stacks is approached from higher temperatures. These changes are explained on the basis of the charge transfer, the shape of the lower empty TCNQ molecular orbitals and the deformation of TCNQ during the pre-transitional CDW fluctuations. Finally the data suggest that the internal stack deformation consisting in a substantial out of plane displacement of the central ring with respect to the cyano-groups allows to gain C α -C α bonding energy which helps the stabilization of the Peierls transition on the TCNQ stack.

  10. Nano-scale spatial assessment of calcium distribution in coccolithophores using synchrotron-based nano-CT and STXM-NEXAFS.

    PubMed

    Sun, Shiyong; Yao, Yanchen; Zou, Xiang; Fan, Shenglan; Zhou, Qing; Dai, Qunwei; Dong, Faqin; Liu, Mingxue; Nie, Xiaoqin; Tan, Daoyong; Li, Shuai

    2014-01-01

    Calcified coccolithophores generate calcium carbonate scales around their cell surface. In light of predicted climate change and the global carbon cycle, the biomineralization ability of coccoliths has received growing interest. However, the underlying biomineralization mechanism is not yet well understood; the lack of non-invasive characterizing tools to obtain molecular level information involving biogenic processes and biomineral components remain significant challenges. In the present study, synchrotron-based Nano-computed Tomography (Nano-CT) and Scanning Transmission X-ray Microscopy-Near-edge X-ray Absorption Fine Structure Spectromicroscopy (STXM-NEXAFS) techniques were employed to identify Ca spatial distribution and investigate the compositional chemistry and distinctive features of the association between biomacromolecules and mineral components of calcite present in coccoliths. The Nano-CT results show that the coccolith scale vesicle is similar as a continuous single channel. The mature coccoliths were intracellularly distributed and immediately ejected and located at the exterior surface to form a coccoshpere. The NEXAFS spectromicroscopy results of the Ca L edge clearly demonstrate the existence of two levels of gradients spatially, indicating two distinctive forms of Ca in coccoliths: a crystalline-poor layer surrounded by a relatively crystalline-rich layer. The results show that Sr is absorbed by the coccoliths and that Sr/Ca substitution is rather homogeneous within the coccoliths. Our findings indicate that synchrotron-based STXM-NEXAFS and Nano-CT are excellent tools for the study of biominerals and provide information to clarify biomineralization mechanism. PMID:25530614

  11. Nano-Scale Spatial Assessment of Calcium Distribution in Coccolithophores Using Synchrotron-Based Nano-CT and STXM-NEXAFS

    PubMed Central

    Sun, Shiyong; Yao, Yanchen; Zou, Xiang; Fan, Shenglan; Zhou, Qing; Dai, Qunwei; Dong, Faqin; Liu, Mingxue; Nie, Xiaoqin; Tan, Daoyong; Li, Shuai

    2014-01-01

    Calcified coccolithophores generate calcium carbonate scales around their cell surface. In light of predicted climate change and the global carbon cycle, the biomineralization ability of coccoliths has received growing interest. However, the underlying biomineralization mechanism is not yet well understood; the lack of non-invasive characterizing tools to obtain molecular level information involving biogenic processes and biomineral components remain significant challenges. In the present study, synchrotron-based Nano-computed Tomography (Nano-CT) and Scanning Transmission X-ray Microscopy-Near-edge X-ray Absorption Fine Structure Spectromicroscopy (STXM-NEXAFS) techniques were employed to identify Ca spatial distribution and investigate the compositional chemistry and distinctive features of the association between biomacromolecules and mineral components of calcite present in coccoliths. The Nano-CT results show that the coccolith scale vesicle is similar as a continuous single channel. The mature coccoliths were intracellularly distributed and immediately ejected and located at the exterior surface to form a coccoshpere. The NEXAFS spectromicroscopy results of the Ca L edge clearly demonstrate the existence of two levels of gradients spatially, indicating two distinctive forms of Ca in coccoliths: a crystalline-poor layer surrounded by a relatively crystalline-rich layer. The results show that Sr is absorbed by the coccoliths and that Sr/Ca substitution is rather homogeneous within the coccoliths. Our findings indicate that synchrotron-based STXM-NEXAFS and Nano-CT are excellent tools for the study of biominerals and provide information to clarify biomineralization mechanism. PMID:25530614

  12. Comparing the Transfusion Medicine Content of the NBME's Examinations in 1984-85 and 1989-90.

    ERIC Educational Resources Information Center

    Murray, Sara F.; And Others

    1992-01-01

    A study investigated the degree to which enhancement of instruction in blood transfusion medicine (TM) in the medical school curriculum is reflected in performance on 1989-90 National Board of Medical Examiners examinations in comparison with 1984-85. Students performed better on TM-related items than on items generally in 1989-90, suggesting more…

  13. Comparability of ophthalmic diagnoses by clinical and Reading Center examiners in the Visual Acuity Impairment Survey Pilot Study.

    PubMed

    Sperduto, R D; Hiller, R; Podgor, M J; Palmberg, P; Ferris, F L; Wentworth, D

    1986-12-01

    Technologic advances in ophthalmic equipment offer the possibility of replacing direct clinical examinations with Reading Center evaluations of data recorded in epidemiologic studies. Clinical and Reading Center examiners made independent ophthalmic diagnoses of 133 right and 132 left eyes of 138 adults in the Visual Acuity Impairment Survey Pilot Study, carried out in three US cities, Boston, Detroit, and Minneapolis, in August 1981-December 1982. The Reading Center diagnosed eye conditions using only photographic and visual field data collected at the time of the clinical examination. In the comparisons of clinical and Reading Center evaluations reported here, only eyes judged by the examiners to have pathology severe enough to reduce visual acuity to 6/9 or worse were classified as having pathology. (No visual acuity criterion was required for the diagnosis of glaucoma or diabetic retinopathy.) There was agreement in diagnostic assessments between clinical and Reading Center examiners in about 80% of eyes. The kappa statistic, which adjusts for chance agreement, was in the fair to good range: 0.60 for 133 right eyes and 0.62 for 132 left eyes. When the Reading Center examiners were provided with additional information on medical history, refractive error and best corrected visual acuity, the agreement between clinical and Reading Center assessments among the subset of eyes with 6/9 or worse vision again was in the fair to good range, with kappas of 0.61 for 45 right eyes and 0.68 for 48 left eyes. Inter-observer agreement between Reading Center examiners in diagnosing pathology was in the good to excellent range. Use of Reading Centers in future epidemiologic studies should be considered, but elimination of the clinical examinations is not recommended until modifications in the protocol described here have been made and shown to improve levels of agreement between clinical and Reading Center examiners. PMID:3776982

  14. Investigation of reactions between trace gases and functional CuO nanospheres and octahedrons using NEXAFS-TXM imaging

    PubMed Central

    Henzler, Katja; Heilemann, Axel; Kneer, Janosch; Guttmann, Peter; Jia, He; Bartsch, Eckhard; Lu, Yan; Palzer, Stefan

    2015-01-01

    In order to take full advantage of novel functional materials in the next generation of sensorial devices scalable processes for their fabrication and utilization are of great importance. Also understanding the processes lending the properties to those materials is essential. Among the most sought-after sensor applications are low-cost, highly sensitive and selective metal oxide based gas sensors. Yet, the surface reactions responsible for provoking a change in the electrical behavior of gas sensitive layers are insufficiently comprehended. Here, we have used near-edge x-ray absorption fine structure spectroscopy in combination with x-ray microscopy (NEXAFS-TXM) for ex-situ measurements, in order to reveal the hydrogen sulfide induced processes at the surface of copper oxide nanoparticles, which are ultimately responsible for triggering a percolation phase transition. For the first time these measurements allow the imaging of trace gas induced reactions and the effect they have on the chemical composition of the metal oxide surface and bulk. This makes the new technique suitable for elucidating adsorption processes in-situ and under real operating conditions. PMID:26631608

  15. Investigation of reactions between trace gases and functional CuO nanospheres and octahedrons using NEXAFS-TXM imaging

    NASA Astrophysics Data System (ADS)

    Henzler, Katja; Heilemann, Axel; Kneer, Janosch; Guttmann, Peter; Jia, He; Bartsch, Eckhard; Lu, Yan; Palzer, Stefan

    2015-12-01

    In order to take full advantage of novel functional materials in the next generation of sensorial devices scalable processes for their fabrication and utilization are of great importance. Also understanding the processes lending the properties to those materials is essential. Among the most sought-after sensor applications are low-cost, highly sensitive and selective metal oxide based gas sensors. Yet, the surface reactions responsible for provoking a change in the electrical behavior of gas sensitive layers are insufficiently comprehended. Here, we have used near-edge x-ray absorption fine structure spectroscopy in combination with x-ray microscopy (NEXAFS-TXM) for ex-situ measurements, in order to reveal the hydrogen sulfide induced processes at the surface of copper oxide nanoparticles, which are ultimately responsible for triggering a percolation phase transition. For the first time these measurements allow the imaging of trace gas induced reactions and the effect they have on the chemical composition of the metal oxide surface and bulk. This makes the new technique suitable for elucidating adsorption processes in-situ and under real operating conditions.

  16. Investigation of reactions between trace gases and functional CuO nanospheres and octahedrons using NEXAFS-TXM imaging.

    PubMed

    Henzler, Katja; Heilemann, Axel; Kneer, Janosch; Guttmann, Peter; Jia, He; Bartsch, Eckhard; Lu, Yan; Palzer, Stefan

    2015-01-01

    In order to take full advantage of novel functional materials in the next generation of sensorial devices scalable processes for their fabrication and utilization are of great importance. Also understanding the processes lending the properties to those materials is essential. Among the most sought-after sensor applications are low-cost, highly sensitive and selective metal oxide based gas sensors. Yet, the surface reactions responsible for provoking a change in the electrical behavior of gas sensitive layers are insufficiently comprehended. Here, we have used near-edge x-ray absorption fine structure spectroscopy in combination with x-ray microscopy (NEXAFS-TXM) for ex-situ measurements, in order to reveal the hydrogen sulfide induced processes at the surface of copper oxide nanoparticles, which are ultimately responsible for triggering a percolation phase transition. For the first time these measurements allow the imaging of trace gas induced reactions and the effect they have on the chemical composition of the metal oxide surface and bulk. This makes the new technique suitable for elucidating adsorption processes in-situ and under real operating conditions. PMID:26631608

  17. Electronic Structure and Chemistry of Iron-Based Metal Oxide Nanostructured Materials: A NEXAFS Investigation of BiFeO3, Bi2Fe4O9, α-Fe2O3, γ-Fe2O3, and Fe/Fe3O4

    SciTech Connect

    Park,T.; Sambasivan, S.; Fischer, D.; Yoon, W.; Misewich, J.; Wong, S.

    2008-01-01

    We present a systematic and detailed near edge X-ray absorption fine structure (NEXAFS) experimental investigation of the electronic structure and chemistry of iron-based metal oxide nanostructured (FeMONS) materials including BiFeO3, Bi2Fe4O9, a-Fe2O3, ?-Fe2O3, and Fe/Fe3O4. Correlations of the electronic structure and structural chemistry of these intriguing nanomaterials are presented, ranging from the nano to the bulk scale. In this work, variations in the shape, position, and intensity of the O K-edge and Fe L-edge NEXAFS spectra have been analyzed in terms of electronic structure and surface chemistry of the FeMONS materials as compared with that of the bulk. We hypothesize that surface imperfection and surface strain anisotropies in nanoparticles induce distortion and site inequivalency of the oxygen Oh sites around the Fe ion located close to the surface, resulting in an increase in the degree of multiplicity as well as in nonstoichiometric effects in FeMONS materials.

  18. Examining the Internal Validity and Statistical Precision of the Comparative Interrupted Time Series Design by Comparison with a Randomized Experiment

    ERIC Educational Resources Information Center

    St.Clair, Travis; Cook, Thomas D.; Hallberg, Kelly

    2014-01-01

    Although evaluators often use an interrupted time series (ITS) design to test hypotheses about program effects, there are few empirical tests of the design's validity. We take a randomized experiment on an educational topic and compare its effects to those from a comparative ITS (CITS) design that uses the same treatment group as the…

  19. An Analysis of Advanced Placement (AP®) Examinations in Economics and Comparative Government and Politics. Research Report No. 2001-4. ETS RR-01-17

    ERIC Educational Resources Information Center

    Breland, Hunter M.; Oltman, Philip K.

    2001-01-01

    Advanced Placement Program® (AP®) Examinations in Macroeconomics, Microeconomics, and Comparative Government and Politics were studied to examine college course performance and gender differences. It was concluded that students who had received college credit for AP performed as well or better in higher-level college courses in Macroeconomics and…

  20. Examining Teacher Job Satisfaction and Principals' Instructional Supervision Behaviours: A Comparative Study of Turkish Private and Public School Teachers

    ERIC Educational Resources Information Center

    Sungu, Hilmi; Ilgan, Abdurrahman; Parylo, Oksana; Erdem, Mustafa

    2014-01-01

    In spite of a strong body of research examining teacher job satisfaction and teachers' assessment of their principals' behaviours, most studies focus on the educational systems in the first world countries. This quantitative study focuses on a lesser-examined educational context by comparing school teachers' job satisfaction levels…

  1. Rationale and design of the Randomized Evaluation of patients with Stable angina Comparing Utilization of noninvasive Examinations (RESCUE) trial.

    PubMed

    Stillman, Arthur E; Gatsonis, Constantine; Lima, João A C; Black, William C; Cormack, Jean; Gareen, Ilana; Hoffmann, Udo; Liu, Tao; Mavromatis, Kreton; Schnall, Mitchell D; Udelson, James E; Woodard, Pamela K

    2016-09-01

    RESCUE is a phase III, randomized, controlled, multicenter, comparative efficacy study, designed to compare two diagnostic imaging/treatment paradigms that use coronary computed tomography angiography (CCTA) or single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) for assisting in the diagnosis of ischemic heart disease in patients with stable angina symptoms, and guiding subsequent treatment. The study is based on the hypothesis that CCTA as a diagnostic tool is associated with no increase in cardiac risk, decreased cost, and reduced radiation exposure compared with SPECT MPI. The RESCUE trial was funded by the Agency for Healthcare Research and Quality (AHRQ) and the American College of Radiology Imaging Network (ACRIN) Fund for Imaging Innovation, began in 2011, and completed in 2014. PMID:27595676

  2. Comparing Single Case Design Overlap-Based Effect Size Metrics from Studies Examining Speech Generating Device Interventions

    ERIC Educational Resources Information Center

    Chen, Mo; Hyppa-Martin, Jolene K.; Reichle, Joe E.; Symons, Frank J.

    2016-01-01

    Meaningfully synthesizing single case experimental data from intervention studies comprised of individuals with low incidence conditions and generating effect size estimates remains challenging. Seven effect size metrics were compared for single case design (SCD) data focused on teaching speech generating device use to individuals with…

  3. A Comparative Examination of Student Teacher and Intern Perceptions of Teaching Ability at the Preservice and Inservice Stages

    ERIC Educational Resources Information Center

    Clark, Sarah K.; Byrnes, Deborah; Sudweeks, Richard R.

    2015-01-01

    This study investigates how the culminating teacher preparation program (TPP) experience (either student teaching assignment or internship) influences the perceptions teachers report about their ability to perform instructional tasks required of teachers. A multivariate ANOVA test (N = 502) was conducted to compare perceptions of student teachers…

  4. An Examination into the Factors Leading to Superintendent Longevity in Urban, Southern California School Districts: A Comparative Case Study

    ERIC Educational Resources Information Center

    Remland, Michael D.

    2012-01-01

    Within a modern context, superintendents walk a fine line in today's reform minded, accountability centered, sociopolitical setting. To many, the position of public school superintendent is perceived as a job where failure is inevitable. The purpose of this comparative case study was to understand the factors that contribute to superintendent…

  5. A preliminary examination of child well-being of physically abused and neglected children compared to a normative pediatric population.

    PubMed

    Lanier, Paul; Kohl, Patricia L; Raghavan, Ramesh; Auslander, Wendy

    2015-02-01

    Federal mandates require state child welfare systems to monitor and improve outcomes for children in three areas: safety, permanency, and well-being. Research across separate domains of child well-being indicates maltreated children may experience lower pediatric health-related quality of life (HRQL). This study assessed well-being in maltreated children using the Pediatric Quality of Life Inventory (PedsQL 4.0), a widely used measure of pediatric HRQL. The PedsQL 4.0 was used to assess well-being in a sample of children (N = 129) receiving child welfare services following reports of alleged physical abuse or neglect. We compared total scores and domain scores for this maltreated sample to those of a published normative sample. Within the maltreated sample, we also compared well-being by child and family demographic characteristics. As compared with a normative pediatric population, maltreated children reported significantly lower total, physical, and psychosocial health. We found no significant differences in total and domain scores based on child and parent demographics within the maltreated sample. This preliminary exploration indicates children receiving child welfare services have significantly lower well-being status than the general child population and have considerable deficits in social and emotional functioning. These findings support continued investment in maltreatment prevention and services to improve the well-being of victims of maltreatment. PMID:25366676

  6. 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

  7. Toward Quantifying the Mass-Based Hygroscopicity of Individual Submicron Atmospheric Aerosol Particles with STXM/NEXAFS and SEM/EDX

    NASA Astrophysics Data System (ADS)

    Yancey Piens, D.; Kelly, S. T.; OBrien, R. E.; Wang, B.; Petters, M. D.; Laskin, A.; Gilles, M. K.

    2014-12-01

    The hygroscopic behavior of atmospheric aerosols influences their optical and cloud-nucleation properties, and therefore affects climate. Although changes in particle size as a function of relative humidity have often been used to quantify the hygroscopic behavior of submicron aerosol particles, it has been noted that calculations of hygroscopicity based on size contain error due to particle porosity, non-ideal volume additivity and changes in surface tension. We will present a method to quantify the hygroscopic behavior of submicron aerosol particles based on changes in mass, rather than size, as a function of relative humidity. This method results from a novel experimental approach combining scanning transmission x-ray microscopy with near-edge x-ray absorption fine spectroscopy (STXM/NEXAFS), as well as scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM/EDX) on the same individual particles. First, using STXM/NEXAFS, our methods are applied to aerosol particles of known composition ‒ for instance ammonium sulfate, sodium bromide and levoglucosan ‒ and validated by theory. Then, using STXM/NEXAFS and SEM/EDX, these methods are extended to mixed atmospheric aerosol particles collected in the field at the DOE Atmospheric Radiation Measurement (ARM) Climate Research Facility at the Southern Great Planes sampling site in Oklahoma, USA. We have observed and quantified a range of hygroscopic behaviors which are correlated to the composition and morphology of individual aerosol particles. These methods will have implications for parameterizing aerosol mixing state and cloud-nucleation activity in atmospheric models.

  8. Comparing the Effects of Self-Controlled and Examiner-Controlled Feedback on Learning in Children With Developmental Coordination Disorder

    PubMed Central

    Zamani, Mohamad Hosein; Fatemi, Rouholah; Soroushmoghadam, Keyvan

    2015-01-01

    Background: Feedback can improve task learning in children with developmental coordination disorder (DCD). However, the frequency and type of feedback may play different role in learning and needs to more investigations. Objectives: The aim of this study was to evaluate the acquisition and retention of new feedback skills in children with DCD under different frequency of self-control and control examiner feedback. Materials and Methods: In this quasi-experimental study with pretest-posttest design, participants based on their retention were divided into four feedback groups: self-controlled feedback groups with frequencies of 50% and75%, experimenter controls with frequencies of 50% and 75%. The study sample consisted of 24 boys with DCD aged between 9 to 11 years old in Ahvaz City, Iran. Then subjects practiced 30 throwing (6 blocks of 5 attempts) in eighth session. Acquisition test immediately after the last training session, and then the retention test were taken. Data were analyzed using the paired t-test, ANOVA and Tukey tests. Results: The results showed no significant difference between groups in the acquisition phase (P > 0.05). However,in the retention session, group of self-control showed better performance than the control tester group (P < 0.05). Conclusions: Based on the current findings, self-control feedback with high frequency leads to more learning in DCD children. The results of this study can be used in rehabilitation programs to improve performance and learning in children with DCD. PMID:26834805

  9. Comparative examination of female urethral pressure profiles measured by CO2 and H2O infusion techniques.

    PubMed

    Shawer, M; Brown, M; Sutherst, J R

    1983-06-01

    The urethral closure pressure profile (UCPP) was recorded in 100 consecutive patients using both the water infusion and the carbon dioxide infusion methods. Ninety-one per cent of the patients complained of discomfort during CO2 infusion. Thirty-two of the CO2 profiles were distorted due to patient discomfort or shortcomings in the design of the measuring system, and in these no quantitative comparisons could be made. In 68 cases the profile measurements were compared: average maximum closure pressures and functional urethral lengths were slightly less with the CO2 but some individual variations were substantial. We concluded that unreliability and patient reaction make CO2 infusion less suitable than H2O for measuring UCPP. PMID:6405837

  10. Comparing Single Case Design Overlap-Based Effect Size Metrics From Studies Examining Speech Generating Device Interventions.

    PubMed

    Chen, Mo; Hyppa-Martin, Jolene K; Reichle, Joe E; Symons, Frank J

    2016-05-01

    Meaningfully synthesizing single case experimental data from intervention studies comprised of individuals with low incidence conditions and generating effect size estimates remains challenging. Seven effect size metrics were compared for single case design (SCD) data focused on teaching speech generating device use to individuals with intellectual and developmental disabilities (IDD) with moderate to profound levels of impairment. The effect size metrics included percent of data points exceeding the median (PEM), percent of nonoverlapping data (PND), improvement rate difference (IRD), percent of all nonoverlapping data (PAND), Phi, nonoverlap of all pairs (NAP), and Tau(novlap). Results showed that among the seven effect size metrics, PAND, Phi, IRD, and PND were more effective in quantifying intervention effects for the data sample (N = 285 phase or condition contrasts). Results are discussed with respect to issues concerning extracting and calculating effect sizes, visual analysis, and SCD intervention research in IDD. PMID:27119210

  11. C 1s Near Edge X-ray Absorption Fine Structure (NEXAFS) of substituted benzoic acids: a theoretical and experimental study

    SciTech Connect

    Baldea,I.; Schimmelpfennig, B.; Plaschke, M.; Rothe, J.; Schirmer, J.; Trofimov, A.; Fanghaenel, T.

    2007-01-01

    Ab initio calculations are performed to explain the discrete transitions in experimental C 1s-NEXAFS (near edge X-ray absorption fine structure) spectra of various benzoic acid derivates. Transition energies and oscillator strengths of the contributing C 1s-{pi}* excitations are computed using the ADC(2) (second-order algebraic-diagrammatic construction) method. This method is demonstrated to be well suited for the finite electronic systems represented by these simple organic acids. There is good agreement between experiment and theory reproducing all the relevant spectral features. Some transitions can only be assigned based on a theoretical foundation. Remaining discrepancies between experimental and computed spectra are discussed.

  12. Comparative examination of cats with feline leukemia virus-associated enteritis and other relevant forms of feline enteritis.

    PubMed

    Kipar, A; Kremendahl, J; Jackson, M L; Reinacher, M

    2001-07-01

    Cats with feline leukemia virus (FeLV)-associated enteritis (FAE), enteritis of other known viral etiology (parvovirus [PV], enteric coronavirus [CoV]), and enteritis of unknown etiology with histologic features similar to those of FAE and PV enteritis (EUE) and FeLV-negative and FeLV-positive cats without enterocyte alterations were examined. Amount and types of infiltrating leukocytes in the jejunum and activity and cellular constituents of mesenteric lymph nodes, spleen, and bone marrow were determined. PV and CoV infections were confirmed by immunohistologic demonstration of PV and CoV antigen, ultrastructural demonstration of viral particles in the intestinal content, and in situ hybridization for PV genome. FeLV infection was detected by immunohistology for gp70, p27, and p15E. Latent FeLV infection was excluded by polymerase chain reaction methods for exogenous FeLV DNA. Enterocyte lesions involved the crypts in cats with PV enteritis, FAE, and EUE and the villous tips in cats with CoV enteritis. Inflammatory infiltration was generally dominated by mononuclear cells and was moderate in the unaltered intestine and in cats with PV enteritis and marked in cats with FAE, CoV enteritis, and EUE. In cats with EUE, myeloid/histiocyte antigen-positive macrophages were relatively numerous, suggesting recruitment of peripheral blood monocytes. Lymphoid tissues were depleted in cats with PV enteritis and with EUE but were normal or hyperplastic in cats with FAE. Bone marrow activity was decreased in cats with PV enteritis; in cats with FAE or EUE and in FeLV-positive cats without enterocyte alterations, activity was slightly increased. In cats with FAE and PV enteritis, a T-cell-dominated response prevailed. EUE showed some parallels to human inflammatory bowel disease, indicating a potential harmful effect of infiltrating macrophages on the intestinal epithelium. PMID:11467470

  13. A comparative study of mouse embryo freeze-preservation including the examination of a thermoelectric freezing device.

    PubMed

    Schiewe, M C; Schmidt, P M; Wildt, D E

    1987-06-01

    In Study 1 over 2000 4- to 8-cell mouse embryos were randomly pooled and assigned to 1 of 12 treatment groups. A 2 X 2 X 3 factorial design was used to analyze two types of cryoprotectant/post-thaw (PT) dilutions (dimethyl sulfoxide [Me2SO]/stepwise dilution versus glycerol/sucrose dilution), two storage containers (glass ampoules versus plastic straws), and three cooling treatments. Two commercial, controlled-rate freezing machines were examined, employing either nitrogen gas (Planer) or thermoelectric (Glacier) cooling. Embryos were cooled slowly (0.5 degrees C/min) to -35 or -80 degrees C and then cooled rapidly by transfer into liquid nitrogen (LN2). Thawed embryos were cultured for 24 hr after which developmental stage, post-thaw survival (PTS), embryo degeneration rate (EDR), quality grade (QG), and fluorescein diacetate viability grade (VG) were assessed. Overall, PTS and EDR were similar (P greater than 0.05) among the three freezing unit/plunge temperature treatments. Cumulative results of container and cryoprotectant/PT dilution treatments consistently demonstrated greater PTS, QG, and VG ratings and lower EDR values when embryos were frozen in ampoules using glycerol/sucrose dilution. Embryos treated with Me2SO/stepwise dilution were particularly sensitive to freezing damage when stored in plastic straws and plunged into LN2 at -35 degrees C. Study 2 was directed at determining whether Study 1 methods for diluting Me2SO-protected embryos markedly affected PTS rates. Post-thaw culture percentages were no different (P greater than 0.05) for four- to eight-cell Me2SO-treated embryos frozen in ampoules (using the forced-LN2 device), thawed, and diluted either conventionally in reduced concentrations of Me2SO or in the sucrose treatment normally accorded glycerolated embryos.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3595167

  14. Comparative Study of the One-step Nucleic Acid Amplification Assay and Conventional Histological Examination for the Detection of Breast Cancer Sentinel Lymph Node Metastases.

    PubMed

    Terada, Mizuho; Niikura, Naoki; Tsuda, Banri; Masuda, Shinobu; Kumaki, Nobue; Tang, Xiaoyan; Okamura, Takuho; Saito, Yuki; Suzuki, Yasuhiro; Tokuda, Yutaka

    2014-09-01

    Intraoperative sentinel lymph node (SLN) biopsy is widely used in patients with early-stage breast cancer and is conventionally performed using hematoxylin and eosin-based histological examination. The one-step nucleic acid amplification (OSNA) assay is a molecular diagnostic tool and a semi-automated lymph node examination method. The purpose of this study was to compare the performance of the OSNA assay and conventional histological examination with frozen sections (FSs) by using 111 SLN biopsy samples from 89 patients at the Tokai University Hospital. The SLN samples were split into 3 slices: the middle slice was used for FS histological examination and the other slices were used for the OSNA assay. The McNemar test was used to compare the differences in the sensitivity and specificity between the OSNA assay and FS histological examination. The sensitivity of the OSNA assay (97.1%) was less than that of FS histological examination (100%), but this difference was not statistically significant (P = 0.125). The specificity of both the methods was identical (96.9%). Despite previously published results suggesting that the OSNA assay is as reliable as histological examinations, our results indicate that this assay often fails to detect micrometastases or isolated tumor cells in SLNs. PMID:25248427

  15. Comparative Examination of Capercaillie (Tetrao urogallus L.) Behaviour Responses and Semen Quality to Two Methods of Semen Collection

    PubMed Central

    Łukaszewicz, Ewa Teresa; Kowalczyk, Artur Mikołaj; Rzońca, Zenon

    2015-01-01

    Artificial insemination (AI) is very helpful in solving the reproductive and biodiversity problems observed in small, closed avian populations. The successful production of fertilized eggs using AI is dependent on the collection of good quality semen. Two methods of male sexual stimulation and semen collection from captive kept capercaillie (Tetrao urogallus L.), one of the most seriously endangered grouse species in Europe, are compared in this study. Ejaculates were obtained either with the use of a dummy female or by the dorso-abdominal massage method. Differences in the individual responses of the males to the two methods of semen collection as well as in their semen quality were noted. Only sperm concentration (432.4 x 106 mL-1 with dummy female and 614.5 x 106 mL-1 for massage method) was significantly affected by capercaillie stimulation method. Sperm motility and morphology were not affected (P≥0.05). Thus, for semen collection from captive kept capercaillie both methods can be used successfully. The dummy female can be an alternative to dorso-abdominal massage method, commonly used for semen collection from domesticated bird species. PMID:26397704

  16. Vestibular effects of a 7 Tesla MRI examination compared to 1.5 T and 0 T in healthy volunteers.

    PubMed

    Theysohn, Jens M; Kraff, Oliver; Eilers, Kristina; Andrade, Dorian; Gerwig, Marcus; Timmann, Dagmar; Schmitt, Franz; Ladd, Mark E; Ladd, Susanne C; Bitz, Andreas K

    2014-01-01

    Ultra-high-field MRI (7 Tesla (T) and above) elicits more temporary side-effects compared to 1.5 T and 3 T, e.g. dizziness or "postural instability" even after exiting the scanner. The current study aims to assess quantitatively vestibular performance before and after exposure to different MRI scenarios at 7 T, 1.5 T and 0 T. Sway path and body axis rotation (Unterberger's stepping test) were quantitatively recorded in a total of 46 volunteers before, 2 minutes after, and 15 minutes after different exposure scenarios: 7 T head MRI (n = 27), 7 T no RF (n = 22), 7 T only B0 (n = 20), 7 T in & out B0 (n = 20), 1.5 T no RF (n = 20), 0 T (n = 15). All exposure scenarios lasted 30 minutes except for brief one minute exposure in 7 T in & out B0. Both measures were documented utilizing a 3D ultrasound system. During sway path evaluation, the experiment was repeated with eyes both open and closed. Sway paths for all long-lasting 7 T scenarios (normal, no RF, only B0) with eyes closed were significantly prolonged 2 minutes after exiting the scanner, normalizing after 15 minutes. Brief exposure to 7 T B0 or 30 minutes exposure to 1.5 T or 0 T did not show significant changes. End positions after Unterberger's stepping test were significantly changed counter-clockwise after all 7 T scenarios, including the brief in & out B0 exposure. Shorter exposure resulted in a smaller alteration angle. In contrast to sway path, reversal of changes in body axis rotation was incomplete after 15 minutes. 1.5 T caused no rotational changes. The results show that exposure to the 7 Tesla static magnetic field causes only a temporary dysfunction or "over-compensation" of the vestibular system not measurable at 1.5 or 0 Tesla. Radiofrequency fields, gradient switching, and orthostatic dysregulation do not seem to play a role. PMID:24658179

  17. Vestibular Effects of a 7 Tesla MRI Examination Compared to 1.5 T and 0 T in Healthy Volunteers

    PubMed Central

    Theysohn, Jens M.; Kraff, Oliver; Eilers, Kristina; Andrade, Dorian; Gerwig, Marcus; Timmann, Dagmar; Schmitt, Franz; Ladd, Mark E.; Ladd, Susanne C.; Bitz, Andreas K.

    2014-01-01

    Ultra-high-field MRI (7 Tesla (T) and above) elicits more temporary side-effects compared to 1.5 T and 3 T, e.g. dizziness or “postural instability” even after exiting the scanner. The current study aims to assess quantitatively vestibular performance before and after exposure to different MRI scenarios at 7 T, 1.5 T and 0 T. Sway path and body axis rotation (Unterberger's stepping test) were quantitatively recorded in a total of 46 volunteers before, 2 minutes after, and 15 minutes after different exposure scenarios: 7 T head MRI (n = 27), 7 T no RF (n = 22), 7 T only B0 (n = 20), 7 T in & out B0 (n = 20), 1.5 T no RF (n = 20), 0 T (n = 15). All exposure scenarios lasted 30 minutes except for brief one minute exposure in 7 T in & out B0. Both measures were documented utilizing a 3D ultrasound system. During sway path evaluation, the experiment was repeated with eyes both open and closed. Sway paths for all long-lasting 7 T scenarios (normal, no RF, only B0) with eyes closed were significantly prolonged 2 minutes after exiting the scanner, normalizing after 15 minutes. Brief exposure to 7 T B0 or 30 minutes exposure to 1.5 T or 0 T did not show significant changes. End positions after Unterberger's stepping test were significantly changed counter-clockwise after all 7 T scenarios, including the brief in & out B0 exposure. Shorter exposure resulted in a smaller alteration angle. In contrast to sway path, reversal of changes in body axis rotation was incomplete after 15 minutes. 1.5 T caused no rotational changes. The results show that exposure to the 7 Tesla static magnetic field causes only a temporary dysfunction or “over-compensation” of the vestibular system not measurable at 1.5 or 0 Tesla. Radiofrequency fields, gradient switching, and orthostatic dysregulation do not seem to play a role. PMID:24658179

  18. Comparative Achievement on National Dental Board Examination Part I Between Dental Students in Problem-Based Learning and Traditional Educational Tracks.

    ERIC Educational Resources Information Center

    Shuler, Charles F.; Fincham, Alan G.

    1998-01-01

    A study compared the performance on a national licensing examination of University of Southern California dental students in problem-based learning (PBL) versus those in conventional educational tracks. PBL track students scored significantly higher in all four discipline-based portions of the exam and also in the aggregate, and scored well in…

  19. A Comparative Examination of Schools' Responses to Bereavement and the Associated Needs of the School Community in Galway, West of Ireland and Derry, Northern Ireland

    ERIC Educational Resources Information Center

    McGovern, Marguerita; Tracey, Anne

    2010-01-01

    The aim and objective of this study is to examine and compare how schools in Galway, Republic of Ireland and Derry in the North of Ireland (cities located within two independent jurisdictions in Ireland) manage and respond to bereavement. To carry out a survey of schools, the "Loss in Schools" questionnaire is considered the most suitable tool.…

  20. Examination of the Effects of Dimensionality on Cognitive Processing in Science: A Computational Modeling Experiment Comparing Online Laboratory Simulations and Serious Educational Games

    ERIC Educational Resources Information Center

    Lamb, Richard L.

    2016-01-01

    Within the last 10 years, new tools for assisting in the teaching and learning of academic skills and content within the context of science have arisen. These new tools include multiple types of computer software and hardware to include (video) games. The purpose of this study was to examine and compare the effect of computer learning games in the…

  1. Test Anxiety and Test Performance: Comparing Paper-based and Computer-Adaptive Versions of the Graduate Record Examinations (GRE) General Test.

    ERIC Educational Resources Information Center

    Powers, Donald E.

    2001-01-01

    Tests the hypothesis that the introduction of computer-adaptive testing may help to alleviate test anxiety and diminish the relationship between test anxiety and test performance. Compares a sample of Graduate Record Examinations (GRE) General Test takers who took the computer-adaptive version of the test with another sample who took the…

  2. Soft X-ray-induced decomposition of amino acids: An XPS, massspectrometry, and NEXAFS study

    SciTech Connect

    Zubavichus, Y.; Fuchs, O.; Weinhardt, L.; Heske, C.; Umbach, E.; Denlinger, J.D.; Grunze, M.

    2003-02-26

    Decomposition of five amino acids, viz. alanine, serine,cysteine, aspartic acid, and asparagine under soft X-ray irradiation (MgKα X-ray source) in ultra-high vacuum has been studied by meansof XPS and mass-spectrometry. A comparative analysis of changes in XPSline shapes, stoichiometry, and residual gas composition indicates thatthe molecules decompose via severalpathways. Dehydration,decarboxylation, decarbonylation, deamination, and desulfurization ofpristine molecules accompanied by desorption of H2, H2O, CO2, CO, NH3,H2S are observed with rates depending on the specific amino acid. NEXAFSspectra of cysteine at the C, O, N K- and S L2,3-edges complement the XPSand mass-spectrometry data and show that exposure of the sample to anintense soft X-ray synchrotron beam results in a formation of C-C and C-Ndouble and triple bonds. Qualitatively, the studied amino acids can bearranged in the following ascending order for radiation stability: serine

  3. Use of circumsporozoite protein enzyme-linked immunosorbent assay compared with microscopic examination of salivary glands for calculation of malaria infectivity rates in mosquitoes (Diptera: Culicidae) from Cameroon.

    PubMed

    Fontenille, D; Meunier, J Y; Nkondjio, C A; Tchuinkam, T

    2001-05-01

    A survey in Cameroon compared the usefulness of the circumsporozoite protein enzyme-linked immunosorbent assay (CSP ELISA) to dissection and microscopic examination of anopheline salivary glands for measuring infectivity rates in anopheline mosquitoes. The salivary glands of 375 females, belonging to four species were examined for sporozoites. After microscopic examination, the glands as well as all the remaining heads and thoraces were tested by ELISA. The sensitivity of ELISA was 100% (18/18), confidence interval (CI) (78.1-100) and the specificity was 99.7% (357/358), CI (98.2 100). The Kappa value, agreement between examination of the glands and salivary gland ELISA, was 0.97. The head thorax CSP ELISA overestimated the true salivary gland infection rate by 12.0%. The results obtained in Central Africa in a village with perennial transmission highly justified the use of the ELISA for measuring the entomological inoculation rate. PMID:11372973

  4. Vibrationally resolved NEXAFS at C and N K-edges of pyridine, 2-fluoropyridine and 2,6-difluoropyridine: A combined experimental and theoretical assessment

    NASA Astrophysics Data System (ADS)

    Baiardi, Alberto; Mendolicchio, Marco; Barone, Vincenzo; Fronzoni, Giovanna; Cardenas Jimenez, Gustavo Adolfo; Stener, Mauro; Grazioli, Cesare; de Simone, Monica; Coreno, Marcello

    2015-11-01

    In the present work, the near edge X-ray absorption spectroscopy (NEXAFS) spectra at both C and N K-edges of pyridine, 2-fluoropyridine, and 2,6-difluoropyridine have been studied both experimentally and theoretically. From an electronic point of view, both transition potential density functional theory and time-dependent density functional theory approaches lead to reliable results provided that suitable basis sets and density functionals are employed. In this connection, the global hybrid B3LYP functional in conjunction with the EPR-III basis set appears particularly suitable after constant scaling of the band positions. For the N K-edge, vertical energies obtained at these levels and broadened by symmetric Gaussian distributions provide spectra in reasonable agreement with the experiment. Vibronic contributions further modulate the band-shapes leading to a better agreement with the experimental results, but are not strictly necessary for semi-quantitative investigations. On the other hand, vibronic contributions are responsible for strong intensity redistribution in the NEXAFS C K-edge spectra, and their inclusion is thus mandatory for a proper description of experiments. In this connection, the simple vertical gradient model is particularly appealing in view of its sufficient reliability and low computational cost. For more quantitative results, the more refined vertical Hessian approach can be employed, and its effectiveness has been improved thanks to a new least-squares fitting approach.

  5. Vibrationally resolved NEXAFS at C and N K-edges of pyridine, 2-fluoropyridine and 2,6-difluoropyridine: A combined experimental and theoretical assessment.

    PubMed

    Baiardi, Alberto; Mendolicchio, Marco; Barone, Vincenzo; Fronzoni, Giovanna; Cardenas Jimenez, Gustavo Adolfo; Stener, Mauro; Grazioli, Cesare; de Simone, Monica; Coreno, Marcello

    2015-11-28

    In the present work, the near edge X-ray absorption spectroscopy (NEXAFS) spectra at both C and N K-edges of pyridine, 2-fluoropyridine, and 2,6-difluoropyridine have been studied both experimentally and theoretically. From an electronic point of view, both transition potential density functional theory and time-dependent density functional theory approaches lead to reliable results provided that suitable basis sets and density functionals are employed. In this connection, the global hybrid B3LYP functional in conjunction with the EPR-III basis set appears particularly suitable after constant scaling of the band positions. For the N K-edge, vertical energies obtained at these levels and broadened by symmetric Gaussian distributions provide spectra in reasonable agreement with the experiment. Vibronic contributions further modulate the band-shapes leading to a better agreement with the experimental results, but are not strictly necessary for semi-quantitative investigations. On the other hand, vibronic contributions are responsible for strong intensity redistribution in the NEXAFS C K-edge spectra, and their inclusion is thus mandatory for a proper description of experiments. In this connection, the simple vertical gradient model is particularly appealing in view of its sufficient reliability and low computational cost. For more quantitative results, the more refined vertical Hessian approach can be employed, and its effectiveness has been improved thanks to a new least-squares fitting approach. PMID:26627945

  6. Electronic structure of individual hybrid colloid particles studied by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy in the X-ray microscope.

    PubMed

    Henzler, Katja; Guttmann, Peter; Lu, Yan; Polzer, Frank; Schneider, Gerd; Ballauff, Matthias

    2013-02-13

    The electronic structure of individual hybrid particles was studied by nanoscale near-edge X-ray absorption spectromicroscopy. The colloidal particles consist of a solid polystyrene core and a cross-linked poly-N-(isopropylacrylamide) shell with embedded crystalline titanium dioxide (TiO(2)) nanoparticles (d = 6 ± 3 nm). The TiO(2) particles are generated in the carrier network by a sol-gel process at room temperature. The hybrid particles were imaged with photon energy steps of 0.1 eV in their hydrated environment with a cryo transmission X-ray microscope (TXM) at the Ti L(2,3)-edge. By analyzing the image stacks, the obtained near-edge X-ray absorption fine structure (NEXAFS) spectra of our individual hybrid particles show clearly that our synthesis generates TiO(2) in the anastase phase. Additionally, our spectromicroscopy method permits the determination of the density distribution of TiO(2) in single carrier particles. Therefore, NEXAFS spectroscopy combined with TXM presents a unique method to get in-depth insight into the electronic structure of hybrid materials. PMID:23360082

  7. Microscopic origin of the charge transfer in single crystals based on thiophene derivatives: A combined NEXAFS and density functional theory approach

    NASA Astrophysics Data System (ADS)

    Chernenkaya, A.; Morherr, A.; Backes, S.; Popp, W.; Witt, S.; Kozina, X.; Nepijko, S. A.; Bolte, M.; Medjanik, K.; Öhrwall, G.; Krellner, C.; Baumgarten, M.; Elmers, H. J.; Schönhense, G.; Jeschke, H. O.; Valentí, R.

    2016-07-01

    We have investigated the charge transfer mechanism in single crystals of DTBDT-TCNQ and DTBDT-F4TCNQ (where DTBDT is dithieno[2,3-d;2',3'-d'] benzo[1,2-b;4,5-b']dithiophene) using a combination of near-edge X-ray absorption spectroscopy (NEXAFS) and density functional theory calculations (DFT) including final state effects beyond the sudden state approximation. In particular, we find that a description that considers the partial screening of the electron-hole Coulomb correlation on a static level as well as the rearrangement of electronic density shows excellent agreement with experiment and allows to uncover the details of the charge transfer mechanism in DTBDT-TCNQ and DTBDT-F4 TCNQ, as well as a reinterpretation of previous NEXAFS data on pure TCNQ. Finally, we further show that almost the same quality of agreement between theoretical results and experiment is obtained by the much faster Z+1/2 approximation, where the core hole effects are simulated by replacing N or F with atomic number Z with the neighboring atom with atomic number Z+1/2.

  8. Vibrationally resolved NEXAFS at C and N K-edges of pyridine, 2-fluoropyridine and 2,6-difluoropyridine: A combined experimental and theoretical assessment

    SciTech Connect

    Baiardi, Alberto; Mendolicchio, Marco; Barone, Vincenzo; Fronzoni, Giovanna; Cardenas Jimenez, Gustavo Adolfo; Stener, Mauro; Grazioli, Cesare; Simone, Monica de; Coreno, Marcello

    2015-11-28

    In the present work, the near edge X-ray absorption spectroscopy (NEXAFS) spectra at both C and N K-edges of pyridine, 2-fluoropyridine, and 2,6-difluoropyridine have been studied both experimentally and theoretically. From an electronic point of view, both transition potential density functional theory and time-dependent density functional theory approaches lead to reliable results provided that suitable basis sets and density functionals are employed. In this connection, the global hybrid B3LYP functional in conjunction with the EPR-III basis set appears particularly suitable after constant scaling of the band positions. For the N K-edge, vertical energies obtained at these levels and broadened by symmetric Gaussian distributions provide spectra in reasonable agreement with the experiment. Vibronic contributions further modulate the band-shapes leading to a better agreement with the experimental results, but are not strictly necessary for semi-quantitative investigations. On the other hand, vibronic contributions are responsible for strong intensity redistribution in the NEXAFS C K-edge spectra, and their inclusion is thus mandatory for a proper description of experiments. In this connection, the simple vertical gradient model is particularly appealing in view of its sufficient reliability and low computational cost. For more quantitative results, the more refined vertical Hessian approach can be employed, and its effectiveness has been improved thanks to a new least-squares fitting approach.

  9. Fundamental aspects of enantioselective heterogeneous catalysis: a NEXAFS study of methyl pyruvate and ( S)-(-)-1-(1-naphthyl) ethylamine on Pt{1 1 1}

    NASA Astrophysics Data System (ADS)

    Bonello, J. M.; Sykes, E. C. H.; Lindsay, R.; Williams, F. J.; Santra, A. K.; Lambert, R. M.

    2001-06-01

    Near-edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy have been used to characterise the adsorption and reactivity of methyl pyruvate and ( S)-(-)-1-(1-napthyl) ethylamine (( S)-NEA) on Pt{1 1 1}. Methyl pyruvate polymerises at room temperature yielding chains that contain CO bonds and no CC bonds; the CO bonds are inclined at 64±5° with respect to the metal surface. Polymerisation probably occurs by an aldol condensation that involves elimination of methanol. This mechanism is in excellent accord with the intramolecular bonding deduced from the NEXAFS results. These findings suggest that irreversible deactivation during start-up or steady state operation of Pt catalysts during enantioselective hydrogenation of alkyl pyruvates can be due to hydrogen starvation, which results in polymerisation of the prochiral reactant. For ( S)-NEA, the naphthalene ring is inclined at 46±5° with respect to the metal surface. It is proposed that ( S)-NEA binds to the surface via contributions from both the aromatic π-system and the lone pair of electrons on the amine nitrogen atom.

  10. Impact of Ferrocene on the Structure of Diesel Exhaust Soot as Probed with Wide-Angle X-ray Scattering and C(1s) NEXAFS Spectroscopy

    SciTech Connect

    Braun,A.; Huggins, F.; Kelly, K.; Mun, B.; Ehrlich, S.; Huffman, G.

    2006-01-01

    We report on the structure of a set of diesel exhaust samples that were obtained from reference diesel fuel and diesel fuel mixed with ferrocene. Characterization was carried out with X-ray absorption spectroscopy (C(1s) NEXAFS) and wide-angle X-ray scattering (WAXS). The reference diesel soot shows a pronounced graphite-like microstructure and molecular structure, with a strong (0 0 2) graphite Bragg reflex and a strong aromatic C{double_bond}C resonance at 285 eV. The mineral matter in the reference soot could be identified as Fe{sub 2}O{sub 3} hematite. The soot specimen from the diesel mixed with ferrocene has an entirely different structure and lacks significantly in graphite-like characteristics. NEXAFS spectra of such soot barely show aromatics but pronounced contributions from aliphatic structures. WAXS patterns show almost no intensity at the Bragg (0 0 2) reflection of graphite, but a strong aliphatic {gamma}-side band. The iron from the ferrocene transforms to Fe{sub 2}O{sub 3} maghemite.

  11. Adsorption of acetic acid on ice studied by ambient-pressure XPS and partial-electron-yield NEXAFS spectroscopy at 230-240 K.

    PubMed

    Křepelová, Adéla; Bartels-Rausch, Thorsten; Brown, Matthew A; Bluhm, Hendrik; Ammann, Markus

    2013-01-17

    Ice plays a key role in the environment, and the ice-air interface influences heterogeneous chemical reactions between snowpack or cirrus clouds and the surrounding air. Soluble gases have been suspected to affect the topmost, disordered layer on ice (often referred to as a quasiliquid layer, QLL). Changes are especially expected in the hydrogen-bonding structure of water in the presence of solutes at the ice surface. Here, we used ambient-pressure X-ray photoelectron spectroscopy (XPS) to detect acetic acid at the ice surface at 230-240 K under atmospheric conditions for the first time. Electron-kinetic-energy-dependent C 1s spectra indicate that acetic acid remains confined to the topmost ice surface layers. Spectral analysis provides information about the protonation state of acetate at the ice surface. Surface-sensitive Auger-electron-yield C-edge near-edge X-ray absorption fine structure (NEXAFS) spectra were recorded to probe the molecular state of the adsorbed species. The O-edge NEXAFS spectra show only minor differences between clean ice and ice with adsorbed acetic acid and thus indicate that acetic acid does not lead to an extended disordered layer on the ice surface between 230 and 240 K. PMID:23252403

  12. Micro- and nano-environments of C sequestration in soil: a multi-elemental STXM-NEXAFS assessment of black C and organomineral associations.

    PubMed

    Solomon, Dawit; Lehmann, Johannes; Wang, Jian; Kinyangi, James; Heymann, Karen; Lu, Yingshen; Wirick, Sue; Jacobsen, Chris

    2012-11-01

    Black C is an essential component of the terrestrial C pool and its formation is often credited as a CO(2) sink by transferring the fast-cycling C from the atmosphere-biosphere system into slower cycling C in the geosphere. This study is the first multi-element K- (C, N, Ca, Fe, Al and Si) soft-X-ray STXM-NEXAFS investigation conducted at a submicron-scale spatial resolution specifically targeting black C and its interaction with the mineral and non-black C organic matter in the organomineral assemblage. The STXM-NEXAFS micrographs and spectra demonstrated that pyrogenic C was dominated by quinoide, aromatic, phenol, ketone, alcohol, carboxylic and hydroxylated- and ether-linked C species. There was also evidence for the presence of pyridinic, pyridonic, pyrrolic, amine and nitril N functionalities. The non-black C organic matter contained amino acids, amino sugars, nucleic acids and polysaccharides known to exhibit negatively charged carboxylic, phenolic, enolic, thiolate and phosphate functionalities highly reactive towards metal ions and black C. The metal-rich mineral matrix was composed of phyllosilicate clay minerals, Fe and Al hydroxypolycations, oxides, hydroxides and oxyhydroxide that can attract and bind organic biopolymers. STXM-NEXAFS provided evidence for interactive association between pyrogenic C, non-black C organic matter and the mineral oxide and oxyhydroxide communities in the organomineral interface. These intimate associations occurred through a "two-way" direct linkage between black C and the mineral or non-black C organic matter or via a "three-way" indirect association where non-black C organic matter could serve as a molecular cross-linking agent binding black C with the mineral matrix or vice versa where inorganic oxides, hydroxides and polycations could act as a bridge to bind black C with non-black C organic matter. The binding and sequestration of black C in the investigated micro- and nano-C repository environments seem to be the

  13. Examination of the Effects of Dimensionality on Cognitive Processing in Science: A Computational Modeling Experiment Comparing Online Laboratory Simulations and Serious Educational Games

    NASA Astrophysics Data System (ADS)

    Lamb, Richard L.

    2016-02-01

    Within the last 10 years, new tools for assisting in the teaching and learning of academic skills and content within the context of science have arisen. These new tools include multiple types of computer software and hardware to include (video) games. The purpose of this study was to examine and compare the effect of computer learning games in the form of three-dimensional serious educational games, two-dimensional online laboratories, and traditional lecture-based instruction in the context of student content learning in science. In particular, this study examines the impact of dimensionality, or the ability to move along the X-, Y-, and Z-axis in the games. Study subjects ( N = 551) were randomly selected using a stratified sampling technique. Independent strata subsamples were developed based upon the conditions of serious educational games, online laboratories, and lecture. The study also computationally models a potential mechanism of action and compares two- and three-dimensional learning environments. F test results suggest a significant difference for the main effect of condition across the factor of content gain score with large effect. Overall, comparisons using computational models suggest that three-dimensional serious educational games increase the level of success in learning as measured with content examinations through greater recruitment and attributional retraining of cognitive systems. The study supports assertions in the literature that the use of games in higher dimensions (i.e., three-dimensional versus two-dimensional) helps to increase student understanding of science concepts.

  14. Combining in situ NEXAFS spectroscopy and CO₂ methanation kinetics to study Pt and Co nanoparticle catalysts reveals key insights into the role of platinum in promoted cobalt catalysis.

    PubMed

    Beaumont, Simon K; Alayoglu, Selim; Specht, Colin; Michalak, William D; Pushkarev, Vladimir V; Guo, Jinghua; Kruse, Norbert; Somorjai, Gabor A

    2014-07-16

    The mechanistic role of platinum and precious metals in promoting cobalt hydrogenation catalysts of the type used in reactions such as Fischer-Tropsch synthesis is highly debated. Here we use well-defined monometallic Pt and Co nanoparticles (NPs) and CO2 methanation as a probe reaction to show that Pt NPs deposited near Co NPs can enhance the CO2 methanation rate by up to a factor of 6 per Co surface atom. In situ NEXAFS spectroscopy of these same Pt NP plus Co NP systems in hydrogen shows that the presence of nearby Pt NPs is able to significantly enhance reduction of the Co at temperatures relevant to Fischer-Tropsch synthesis and CO2 methanation. The mechanistic role of Pt in these reactions is discussed in light of these findings. PMID:24978060

  15. Inequitable walking conditions among older people: examining the interrelationship of neighbourhood socio-economic status and urban form using a comparative case study

    PubMed Central

    2010-01-01

    Background Supportive neighbourhood walking conditions are particularly important for older people as they age and who, as a group, prefer walking as a form of physical activity. Urban form and socio-economic status (SES) can influence neighbourhood walking behaviour. The objectives of this study were: a) to examine how urban form and neighbourhood SES inter-relate to affect the experiences of older people who walk in their neighbourhoods; b) to examine differences among neighbourhood stakeholder key informant perspectives on socio-political processes that shape the walkability of neighbourhood environments. Methods An embedded comparative case study examined differences among four Ottawa neighbourhoods that were purposefully selected to provide contrasts on urban form (inner-urban versus suburban) and SES (higher versus lower). Qualitative data collected from 75 older walkers and 19 neighbourhood key informants, as well as quantitative indicators were compared on the two axes of urban form and SES among the four neighbourhoods. Results and discussion Examining the inter-relationship of neighbourhood SES and urban form characteristics on older people's walking experiences indicated that urban form differences were accentuated positively in higher SES neighbourhoods and negatively in lower SES neighbourhoods. Older people in lower SES neighbourhoods were more affected by traffic hazards and more reliant on public transit compared to their higher SES counterparts. In higher SES neighbourhoods the disadvantages of traffic in the inner-urban neighbourhood and lack of commercial destinations in the suburban neighbourhood were partially offset by other factors including neighbourhood aesthetics. Key informant descriptions of the socio-political process highlighted how lower SES neighbourhoods may face greater challenges in creating walkable places. These differences pertained to the size of neighbourhood associations, relationships with political representatives

  16. Interactions of short-acting, intermediate-acting and pre-mixed human insulins with free radicals--Comparative EPR examination.

    PubMed

    Olczyk, Paweł; Komosinska-Vassev, Katarzyna; Ramos, Paweł; Mencner, Łukasz; Olczyk, Krystyna; Pilawa, Barbara

    2015-07-25

    Electron paramagnetic resonance (EPR) spectroscopy was used to examine insulins interactions with free radicals. Human recombinant DNA insulins of three groups were studied: short-acting insulin (Insuman Rapid); intermediate-acting insulins (Humulin N, Insuman Basal), and pre-mixed insulins (Humulin M3, Gensulin M50, Gensulin M40, Gensulin M30). The aim of an X-band (9.3GHz) study was comparative analysis of antioxidative properties of the three groups of human insulins. DPPH was used as a stable free radical model. Amplitudes of EPR lines of DPPH as the paramagnetic free radical reference, and DPPH interacting with the individual tested insulins were compared. For all the examined insulins kinetics of their interactions with free radicals up to 60 min were obtained. The strongest interactions with free radicals were observed for the short-acting insulin - Insuman Rapid. The lowest interactions with free radicals were characteristic for intermediate-acting insulin - Insuman Basal. The pre-mixed insulins i.e. Humulin M3 and Gensulin M50 revealed the fastest interactions with free radicals. The short acting, intermediate acting and premixed insulins have been found to be effective agents in reducing free radical formation in vitro and should be further considered as potential useful tools in attenuation of oxidative stress in diabetic patients. PMID:25975232

  17. Formation of Chromium Coating and Comparative Examination on Corrosion Resistance with 13Cr Steel in CO2-SATURATED Simulated Oilfield Brine

    NASA Astrophysics Data System (ADS)

    Zou, Jiaojuan; Xie, Faqin; Lin, Naiming; Yao, Xiaofei; Tian, Wei; Tang, Bin

    2013-08-01

    In order to enhance the surface properties of P110 oil casing tube steel and increase its usage during operation, chromium coating was fabricated by pack cementation. Scanning electron microscope, energy dispersive spectrometry and X-ray diffraction were used to investigate the surface morphology, cross-sectional microstructure, element distribution and phase constitutions of the coating. Comparative examinations on corrosion resistance between chromium coating and 13Cr stainless steel in CO2-saturated simulated oilfield brine were carried out via electrochemical measurements. The results showed that the obtained coating was uniform and compact, mainly consisted of CrxCy and doped with minor Cr2N. Chromizing treatment made it possible to create on the working surface of P110 steel with enhanced corrosion resistance, and the chromium coating indicated lower pitting corrosion sensitivity than that of 13Cr stainless steel.

  18. Preliminary optical design of a varied line-space spectrograph for the multi-channel detection of near-edge X-ray absorption fine structure (NEXAFS) spectra in the 280-550 eV energy range

    SciTech Connect

    Wheeler, B.S.; McKinney, W.R.; Hussain, Z.; Padmore, H.

    1996-07-01

    The optical design of a varied line-space spectrograph for the multi-channel recording of NEXAFS spectra in a single {open_quotes}snapshot{close_quotes} is proposed. The spectrograph is to be used with a bending magnet source on beamline 7.3.2 at the Advanced Light Source (ALS). Approximately 20 volts of spectra are simultaneously imaged across a small square of material sample at each respective K absorption edge of carbon, nitrogen, and oxygen. Photoelectrons emitted from the material sample will be collected by an electron imaging microscope, the view field of which determines the sampling size. The sample also forms the exit slit of the optical system. This dispersive method of NEXAFS data acquisition is three to four orders of magnitude faster than the conventional method of taking data point-to-point using scanning of the grating. The proposed design is presented along with the design method and supporting SHADOW raytrace analysis.

  19. Probing the Orientation and Conformation of alpha-Helix and beta-Strand Model Peptides on Self-Assembled Monolayers Using Sum Frequency Generation and NEXAFS Spectroscopy

    SciTech Connect

    Weidner, T.; Apte, J; Gamble, L; Castner, D

    2010-01-01

    The structure and orientation of amphiphilic {alpha}-helix and {beta}-strand model peptide films on self-assembled monolayers (SAMs) have been studied with sum frequency generation (SFG) vibrational spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The {alpha}-helix peptide is a 14-mer, and the {beta}-strand is a 15-mer of hydrophilic lysine and hydrophobic leucine residues with hydrophobic periodicities of 3.5 and 2, respectively. These periodicities result in the leucine side chains located on one side of the peptides and the lysine side chains on the other side. The SAMs were prepared from the assembly of either carboxylic acid- or methyl-terminated alkyl thiols onto gold surfaces. For SFG studies, the deuterated analog of the methyl SAM was used. SFG vibrational spectra in the C-H region of air-dried peptides films on both SAMs exhibit strong peaks near 2965, 2940, and 2875 cm{sup -1} related to ordered leucine side chains. The orientation of the leucine side chains was determined from the phase of these features relative to the nonresonant gold background. The relative phase for both the {alpha}-helix and {beta}-strand peptides showed that the leucine side chains were oriented away from the carboxylic acid SAM surface and oriented toward the methyl SAM surface. Amide I peaks observed near 1656 cm{sup -1} for the {alpha}-helix peptide confirm that the secondary structure is preserved on both SAMs. Strong linear dichroism related to the amide {pi}* orbital at 400.8 eV was observed in the nitrogen K-edge NEXAFS spectra for the adsorbed {beta}-strand peptides, suggesting that the peptide backbones are oriented parallel to the SAM surface with the side chains pointing toward or away from the interface. For the {alpha}-helix the dichroism of the amide {pi}* is significantly weaker, probably because of the broad distribution of amide bond orientations in the {alpha}-helix secondary structure.

  20. Quantitative and comparative examination of the spectral features characteristics of the surface reflectance information retrieved from the atmospherically corrected images of Hyperion

    NASA Astrophysics Data System (ADS)

    Kayadibi, Önder; Aydal, Doğan

    2013-01-01

    The retrieval of surface reflectance information from the same single pixel of the Hyperion image atmospherically corrected by using image-based [internal average relative reflectance (IARR), log residuals, and flat field] and radiative transfer model (RTM)-based [the fast line-of-sight atmospheric analysis of spectral hypercubes (FLAASH) and the Atmospheric and Topographic Correction 2 (ATCOR-2)] approaches and the spectral feature characteristics of this information were quantitatively and comparatively examined based on measured ground spectral reflectance data. The spectral features quantitative analysis results of the reflectance data showed that spectral reflectances that are suitable and best fitting to the ground spectral reflectances which were obtained from the pixels of FLAASH, ATCOR-2, and flat field-corrected images, respectively. The retrieval of surface reflectance from the FLAASH-corrected image pixels, in general, produced high scores in spectral parameter analyses. Of the image-based approaches, only in flat field-derived reflectance data, results were obtained which are high and nearest to those of RTM and ground spectral reflectance data. Generally, low scores obtained in the spectral parameter analyses of the surface reflectance values retrieved from single pixels of IARR and log residuals-corrected images showed the results that fit worst to the measured ground spectral reflectance.

  1. "What's Wrong with the Seed?" A Comparative Examination of an Empowering Community-Centered Approach to Recovery in Community Mental Health.

    PubMed

    Jorge-Monteiro, Maria F; Ornelas, José H

    2016-10-01

    This cross-sectional group comparison aimed to examine whether personal empowerment, recovery and community integration were associated with the individual's participation in an empowering community-centered model of intervention. Ninety-three participants from an empowering community-centered community mental health organization were compared with a matched group of individuals from standard interventions of four equivalent organizations. Results showed that participants taking advantage of the empowering community-centered approach were more involved in high recovery-oriented programs; and attained higher levels of personal goals and hope, empowerment, and of community integration. An involvement in high recovery-oriented programs (supported employment or independent housing) revealed improved outcomes for the individual. In conclusion, the findings suggested a transformative impact of the empowering community-centered model both at the individual and the program level by altering the resource accessibility and social conditions for people who experience mental illness. The implications of findings for transforming community mental health practice are discussed in detail. PMID:27072950

  2. Examination of Knowledge and NOS in a PBL Curriculum: Comparing the Impact on Pre-service Teachers and Science Career Undergraduates

    NASA Astrophysics Data System (ADS)

    Schleigh, S.; Manda, A. K.

    2011-12-01

    "Those who don't know or can't do, teach". This is a well known statement accepted by many as an adage. It is a statement that implies that the teachers of our science content really do not understand the science. In this study, we examined whether there was some truth in this statement by comparing undergraduates heading towards science careers and undergraduates heading toward science teaching careers. Do teachers really have a different understanding for science than scientists? If so, do they learn differently from each other? Our study examines content knowledge gains and ability to apply and engage in science using the content that is being addressed. We questioned (1)if students in one track engage and develop knowledge and skills more proficiently than another; (2)if the PBL approach is more effective for a particular group of learners; (3)if the PBL environment (virtual/physical) impacts the development and understanding for NOS; and (4) how the engagement of learning through PBL transfers to classroom practice. We used the Problem Based Approach (PBL) in undergraduate courses that covered the science content related to climate change. Project-based learning (PBL) is an approach to science education that has been shown to support student understanding for science concepts by allowing them to apply knowledge to real-world, relevant applications. Recent research has focused on developing teachers' understanding for science by engaging them in learning events that are found in PBL and authentic research approaches (AR)( e.g. Abd-El-Khalick and Lederman, 2000). We used mixed methods to answer each of our questions. Our instruments included a likert scale for the nature of science as argumentation, a concept mapping activity, a written essay, a content exam and an observation protocol for the teaching practice. In this study we included a total of 40 pre-service teachers (online) 30 pre-service teachers (physical classroom) and 35 undergraduates (physical

  3. Radical cystectomy versus bladder preserving therapy for muscle-invasive urothelial carcinoma: examining confounding and misclassification bias in cancer observational comparative effectiveness research

    PubMed Central

    Bekelman, Justin E.; Handorf, Elizabeth A.; Guzzo, Thomas; Pollack, Craig Evan; Christodouleas, John; Resnick, Matthew J.; Swisher-McClure, Samuel; Vaughn, David; Have, Thomas Ten; Polsky, Daniel; Mitra, Nandita

    2013-01-01

    Objectives Radical cystectomy (RC) is the standard treatment for muscle-invasive Urothelial carcinoma of the bladder (UCB). Tri-modality bladder preserving therapy (BPT) is an alternative to RC, but randomized comparisons of RC versus BPT have proven infeasible. To compare RC versus BPT, we undertook an observational cohort study using registry and administrative claims data from the SEER-Medicare database. Methods We identified patients age 65 years or older diagnosed between 1995 and 2005 who received RC (n=1,426) or BPT (n=417). We examined confounding and stage misclassification in the comparison of RC and BPT using multivariable adjustment, propensity score-based adjustment, instrumental variable (IV) analysis and simulations. Results Patients who received BPT were older and more likely to have comorbid disease. After propensity score adjustment, BPT was associated with an increased hazard of death from any cause (HR 1.26; 95% CI, 1.05 – 1.53) and from bladder cancer (HR 1.31; 95% CI, 0.97 – 1.77). Using the local area cystectomy rate as an instrument, IV analysis demonstrated no differences in survival between BPT and RC (death from any cause HR 1.06; 95% CI, 0.78 – 1.31; death from bladder cancer HR 0.94; 95% CI, 0.55 – 1.18). Simulation studies for stage misclassification yielded results consistent with the IV analysis. Conclusions Survival estimates in an observational cohort of patients who underwent RC versus BPT differ by analytic method. Multivariable and propensity score adjustment revealed greater mortality associated with BPT relative to RC, while IV analysis and simulation studies suggest that the two treatments are associated with similar survival outcomes. PMID:23796296

  4. Eighth-grade science teachers use of instructional time: Examining questions from the Third International Mathematics and Science Study (TIMSS) and comparing TIMSS and National Science Foundation questionnaires

    NASA Astrophysics Data System (ADS)

    Davidson, Anne Burgess

    Did the Third International Mathematics and Science Study (TIMSS) ask science teachers the right questions about their use of instructional time? Part I of this 2-part study used the TIMSS database to answer the question: Do 8th grade science teachers in the U.S., Czech Republic, Hungary, Japan, and Korea differ significantly in their perceived use of instructional time? Using the instructional activities in the TIMSS teacher question "How did the lesson proceed?" the teacher-reported times were analyzed using a repeated measures multivariate analysis. Significant differences were found between teacher-reported times in the U.S. and the other 4 TIMSS countries, whose 8th grade students outperformed U.S. students on TIMSS achievement tests. Post-hoc analysis indicated that TIMSS U.S. 8th grade science teachers report spending more time on homework in class, on group activities, and on lab activities, but less time on topic development, than TIMSS teachers from some or all of the other countries. Part II of this study further examined the question "How did the lesson proceed?" by videotaping 6 classes of 8th grade science in Alabama and Virginia and comparing observer coding of the video to the teachers' recalled descriptions of the same class. The difference between observer and teacher responses using TIMSS categories was not significant; however, 43% of the total variance was explained by whether the teacher or the observer reported the times for the instructional activities. The teachers also responded to questions from the NSF Local Systemic Change Through Teacher Enhancement K--8 Teacher Questionnaire to describe the same class. The difference found between the teacher and the observer coding was not significant, but the amount of variance explained by the data source (observer or teacher) dropped to 33% when using NSF student activity categories and to 26% when using NSF teacher activity categories. The conclusion of this study was that questionnaires to

  5. Comparing the frequency of physical examination techniques performed by associate and baccalaureate degree prepared nurses in clinical practice: does education make a difference?

    PubMed

    Giddens, Jean

    2006-03-01

    Rapid changes in health care have underscored the need for reform in health professions education, including nursing education. One of many problems cited in the nursing and other health sciences education literature is overcrowded curricula; therefore, an evaluation of content is necessary. The purpose of this study was to determine whether differences exist in the frequency that physical examination techniques are performed by associate and baccalaureate degree prepared nurses. Participants completed a survey on performance of various physical examination techniques. A Mann-Whitney test showed no differences between the two groups in terms of frequency of techniques performed. A small negative correlation was found between frequency and years of experience with the nutrition assessment category. A comparison of physical examination content covered in baccalaureate and associate degree nursing programs is needed to further understand these findings. PMID:16562804

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

    PubMed Central

    Willneff, EA; Ormsby, BA; Stevens, JS; Jaye, C; Fischer, DA; Schroeder, SLM

    2014-01-01

    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 results 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. © 2014 The Authors. Surface and Interface Analysis published by John Wiley & Sons, Ltd. PMID:25892829

  7. Examining Attitudes, Enjoyment, Flow, and Physical Activity Levels in Pre-Service Teachers Utilizing the BLISS Model Compared to Traditional Dance Instruction

    ERIC Educational Resources Information Center

    Davis, Christa Ann

    2013-01-01

    This dissertation describes two studies, based on data collection within a pre-existing collegiate course for pre-service teachers in a children's dance setting at a northwest public university. The overall purpose of these experimental studies was to compare traditional movement/dance with the influence of a relevance-based instructional model,…

  8. Nutrient intake, diet quality, and weight/adiposity parameters in breakfast patterns compared with no breakfast in adults: National Health and Nutrition Examination Survey 2001-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of different breakfast consumption patterns on nutrient intake, diet quality, and weight/adiposity status is unknown. The objective was to compare nutrient intake, diet quality, and weight/adiposity measures of consumers assigned to different breakfast patterns with breakfast skippers. Th...

  9. Comparing Regression Discontinuity and Multivariate Analyses of Variance: Examining the Effects of a Vocabulary Intervention for Students at Risk for Reading Disability

    ERIC Educational Resources Information Center

    Ashworth, Kristen E.; Pullen, Paige C.

    2015-01-01

    The purpose of this study was to compare the results of a regression discontinuity design (RDD) with those of an experimental design of a tiered vocabulary intervention for children at risk for reading disability to determine RDD's feasibility as a research methodology for this type of study. Researchers reanalyzed an archival dataset of a…

  10. Comparing Greek-Affiliated Students and Student Athletes: An Examination of the Behavior-Intention Link, Reasons for Drinking, and Alcohol-Related Consequences

    ERIC Educational Resources Information Center

    Huchting, Karie K.; Lac, Andrew; Hummer, Justin F.; LaBrie, Joseph W.

    2011-01-01

    While affiliation with Greek fraternities/sororities and intercollegiate athletic teams is associated with heavier drinking (Meilman et al., 1999), few studies have compared reasons for drinking among these groups. A sample of 1,541 students, identifying as either Greeks or athletes, completed an online survey. Athletes were significantly higher…

  11. Comparative electron microscopy (SEM) examination of Fe, Au, and Zn electrode surfaces polarized in different regions of potentiostatic E/I behavior

    SciTech Connect

    Podesta, J.J.; Arvia, A.J.; Piatti, R.C.V.

    1982-12-01

    The surface morphology of some metals (Fe, Au, and Zn) after potentiostatic polarization was studied through SEM examination. The following electrochemical systems were investigated at 25C: (1) Fe/1 M H/sub 2/SO/sub 4/; (2) Au/1 M HCl; and (3) Zn/2 M NaOH. The polarization potentials were chosen in the active dissolution region, in the passivity region, and in the potential range where periodic oscillations of the anode current are observed. The changes in the morphologies of attack on the various metals were related to the film forming species and of anion adsorption.

  12. An examination of population exposure to traffic related air pollution: Comparing spatially and temporally resolved estimates against long-term average exposures at the home location.

    PubMed

    Shekarrizfard, Maryam; Faghih-Imani, Ahmadreza; Hatzopoulou, Marianne

    2016-05-01

    Air pollution in metropolitan areas is mainly caused by traffic emissions. This study presents the development of a model chain consisting of a transportation model, an emissions model, and atmospheric dispersion model, applied to dynamically evaluate individuals' exposure to air pollution by intersecting daily trajectories of individuals and hourly spatial variations of air pollution across the study domain. This dynamic approach is implemented in Montreal, Canada to highlight the advantages of the method for exposure analysis. The results for nitrogen dioxide (NO2), a marker of traffic related air pollution, reveal significant differences when relying on spatially and temporally resolved concentrations combined with individuals' daily trajectories compared to a long-term average NO2 concentration at the home location. We observe that NO2 exposures based on trips and activity locations visited throughout the day were often more elevated than daily NO2 concentrations at the home location. The percentage of all individuals with a lower 24-hour daily average at home compared to their 24-hour mobility exposure is 89.6%, of which 31% of individuals increase their exposure by more than 10% by leaving the home. On average, individuals increased their exposure by 23-44% while commuting and conducting activities out of home (compared to the daily concentration at home), regardless of air quality at their home location. We conclude that our proposed dynamic modelling approach significantly improves the results of traditional methods that rely on a long-term average concentration at the home location and we shed light on the importance of using individual daily trajectories to understand exposure. PMID:26970897

  13. Application of Electron Paramagnetic Resonance Spectroscopy to Comparative Examination of Different Groups of Free Radicals in Thermal Injuries Treated with Propolis and Silver Sulphadiazine

    PubMed Central

    Olczyk, Pawel; Ramos, Pawel; Bernas, Marcin; Komosinska-Vassev, Katarzyna; Stojko, Jerzy; Pilawa, Barbara

    2013-01-01

    Different groups of free radicals expressed in burn wounds treated with propolis and silver sulphadiazine were examined. The thermal effect forms major types of free radicals in a wound because of the breaking of chemical bonds. Free radicals, located in the heated skin, were tested after 21 days of treating by these two substances. The aim of this work was to find the method for determination of types and concentrations of different groups of free radicals in wound after high temperature impact during burning. The effects of the therapy by propolis and silver sulphadiazine on free radicals were studied. Since the chemical methods of free radicals studies are destructive, the usefulness of the electron paramagnetic resonance spectroscopy was tested in this work. The electron paramagnetic resonance spectra measured with the microwave power of 2.2 mW were numerically fitted by theoretical curves of Gaussian and Lorentzian shapes. The experimental electron paramagnetic resonance spectra of tissue samples are best fitted by the sum of one Gauss and two Lorentz lines. An innovatory numerical procedure of spectroscopic skin analysis was presented. It is very useful in the alternative medicine studies. PMID:23762162

  14. Historical cohort study examining comparative effectiveness of albuterol inhalers with and without integrated dose counter for patients with asthma or chronic obstructive pulmonary disease

    PubMed Central

    Price, David B; Rigazio, Anna; Buatti Small, Mary; Ferro, Thomas J

    2016-01-01

    Background Using a metered-dose inhaler (MDI) beyond the labeled number of actuations may result in inadequate dosing of medication, which can lead to poor clinical outcomes. This study compared respiratory-related emergency department (ED) visit rates in patients with asthma, chronic obstructive pulmonary disease, or both when they used albuterol MDIs with versus without dose counters. Methods This retrospective study used US claims data to identify patients (ages 4–64 years) with asthma, chronic obstructive pulmonary disease, or both, using albuterol MDIs with or without an integrated dose counter. The study comprised a 1-year baseline period for patient characterization and confounder definition and a 1-year outcome period following the first albuterol prescription. The primary end point was the incidence rate of respiratory-related ED visits, compared using a reduced zero-inflated Poisson regression model. We also compared severe exacerbation rates and rescue medication use. Results A total of 93,980 patients were studied, including 67,251 (72%) in the dose counter cohort and 26,729 (28%) in the non-dose-counter cohort. The cohorts were broadly similar at baseline (55,069 [59%] female patients; median age, 37 years). The incidence rate of respiratory-related ED visits during the outcome year was 45% lower in the dose counter cohort than in the non-dose-counter cohort (adjusted rate ratio: 0.55; 95% confidence interval: 0.47–0.64). Exacerbation rates and short-acting β-agonist use were similar between cohorts. Conclusion These findings suggest that dose counter integration into albuterol MDIs is associated with decreased ED visit rates. The presence of integrated dose counters on rescue inhalers can help patients avoid using an empty or near-empty inhaler during exacerbations, thereby ensuring available medication for relief of their symptoms. Integrated dose counters on rescue MDIs could represent a simple and effective tool to improve clinical outcomes

  15. Treatment of chronic diabetic lower extremity ulcers with advanced therapies: a prospective, randomised, controlled, multi-centre comparative study examining clinical efficacy and cost.

    PubMed

    Zelen, Charles M; Serena, Thomas E; Gould, Lisa; Le, Lam; Carter, Marissa J; Keller, Jennifer; Li, William W

    2016-04-01

    Advanced therapies such as bioengineered skin substitutes (BSS) and dehydrated human amnion/chorion membrane (dHACM) have been shown to promote healing of chronic diabetic ulcers. An interim analysis of data from 60 patients enrolled in a prospective, randomised, controlled, parallel group, multi-centre clinical trial showed that dHACM (EpiFix®, MiMedx Group Inc., Marietta, GA) is superior to standard wound care (SWC) and BSS (Apligraf®, Organogenesis, Inc., Canton, MA) in achieving complete wound closure within 4-6 weeks. Rates and time to closure at a longer time interval and factors influencing outcomes remained unassessed; therefore, the study was continued in order to achieve at least 100 patients. With the larger cohort, we compare clinical outcomes at 12 weeks in 100 patients with chronic lower extremity diabetic ulcers treated with weekly applications of Apligraf (n = 33), EpiFix (n = 32) or SWC (n = 35) with collagen-alginate dressing as controls. A Cox regression was performed to analyse the time to heal within 12 weeks, adjusting for all significant covariates. A Kaplan-Meier analysis was conducted to compare time-to-heal within 12 weeks for the three treatment groups. Clinical characteristics were well matched across study groups. The proportion of wounds achieving complete closure within the 12-week study period were 73% (24/33), 97% (31/32), and 51% (18/35) for Apligraf, EpiFix and SWC, respectively (adjusted P = 0·00019). Subjects treated with EpiFix had a very significant higher probability of their wounds healing [hazard ratio (HR: 5·66; adjusted P: 1·3 x 10(-7) ] compared to SWC alone. No difference in probability of healing was observed for the Apligraf and SWC groups. Patients treated with Apligraf were less likely to heal than those treated with EpiFix [HR: 0·30; 95% confidence interval (CI): 0·17-0·54; unadjusted P: 5·8 x 10(-5) ]. Increased wound size and presence of hypertension were significant factors that influenced healing. Mean

  16. Alcoholic beverage consumption by adults compared to dietary guidelines: results of the National Health and Nutrition Examination Survey, 2009-2010.

    PubMed

    Guenther, Patricia M; Ding, Eric L; Rimm, Eric B

    2013-04-01

    The 2010 Dietary Guidelines for Americans (DGA) state that if alcohol is consumed, it should be consumed in moderation, which is defined as up to two drinks in a single day for men and one drink for women. The purpose of this analysis was to estimate the percentages of adults who, on a given day, drank more than these limits and the percentages who drank too heavily; that is, more than four drinks for men and more than three for women. Dietary intake data from the National Health and Nutrition Examination Survey, 2009-2010, were analyzed. Using a computer-assisted protocol, 24-hour dietary recalls were collected from 2,740 men and 2,941 women, age 21 years and older. Results were weighted to be nationally representative. Estimated mean daily intake was 1.2 drinks for men and 0.4 for women (1 drink=14 g of ethanol). On a given day, 36% of men and 21% of women consumed alcohol. Whereas 82% of men and 89% of women did not exceed the DGA's limits, 8% of men had more than four drinks, and 3% of women had more than three, amounts defined as heavy. The percentages who drank more than the DGA's limits varied by age group and were highest among men age 31 to 50 years and women age 51 to 70 years. Excessive drinking is an important health problem and is not limited to college-age individuals. Registered dietitians and other health professionals should be aware of excessive drinking by the adult US population. Consumer education resources are available. PMID:23415501

  17. The alternative DSM-5 personality disorder traits criterion: A comparative examination of three self-report forms in a Danish population.

    PubMed

    Bach, Bo; Maples-Keller, Jessica L; Bo, Sune; Simonsen, Erik

    2016-04-01

    The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013a) offers an alternative model for Personality Disorders (PDs) in Section III, which consists in part of a pathological personality traits criterion measured with the Personality Inventory for DSM-5 (PID-5). The PID-5 selfreport instrument currently exists in the original 220-item form, a short 100-item form, and a brief 25-item form. For clinicians and researchers, the choice of a particular PID- 5 form depends on feasibility, but also reliability and validity. The goal of the present study was to examine the psychometric qualities of all 3 PID-5 forms, simultaneously, based on a Danish sample (N = 1376) of 451 psychiatric outpatients and 925 community-dwelling participants. Scale reliability and factorial validity were satisfactory across all 3 PID-5 forms. The correlational profiles of the short and brief PID-5 forms with clinician-rated PD dimensions were nearly identical with that of the original PID-5 (rICC = .99 and .95, respectively). All 3 forms discriminated appropriately between psychiatric patients and community-dwelling individuals. This supports that all 3 PID-5 forms can be used to reliably and validly assess PD traits and provides initial support for the use of the abbreviated PID-5 forms in a European population. However, only the original 220-item form and the short 100-item form capture all 25 trait facets, and the brief 25-item form may be ideally limited to preliminary screening or situations with substantial time restrictions. (PsycINFO Database Record PMID:26642229

  18. Ear examination

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003340.htm Ear examination To use the sharing features on this page, ... ear References King EF, Couch ME. History, physical examination, and the preoperative evaluation. In: Flint PW, Haughey ...

  19. Comparing spatially varying coefficient models: a case study examining violent crime rates and their relationships to alcohol outlets and illegal drug arrests

    NASA Astrophysics Data System (ADS)

    Wheeler, David C.; Waller, Lance A.

    2009-03-01

    In this paper, we compare and contrast a Bayesian spatially varying coefficient process (SVCP) model with a geographically weighted regression (GWR) model for the estimation of the potentially spatially varying regression effects of alcohol outlets and illegal drug activity on violent crime in Houston, Texas. In addition, we focus on the inherent coefficient shrinkage properties of the Bayesian SVCP model as a way to address increased coefficient variance that follows from collinearity in GWR models. We outline the advantages of the Bayesian model in terms of reducing inflated coefficient variance, enhanced model flexibility, and more formal measuring of model uncertainty for prediction. We find spatially varying effects for alcohol outlets and drug violations, but the amount of variation depends on the type of model used. For the Bayesian model, this variation is controllable through the amount of prior influence placed on the variance of the coefficients. For example, the spatial pattern of coefficients is similar for the GWR and Bayesian models when a relatively large prior variance is used in the Bayesian model.

  20. Comparative examination of various PCR-based methods for DNMT3A and IDH1/2 mutations identification in acute myeloid leukemia

    PubMed Central

    2014-01-01

    Background Mutations in epigenetic modifiers were reported in patients with acute myeloid leukaemia (AML) including mutations in DNA methyltransferase 3A gene (DNMT3A) in 20%-30% patients and mutations in isocitrate dehydrogenase 1/2 gene (IDH1/2) in 5%-15% patients. Novel studies have shown that mutations in DNMT3A and IDH1/2 influence prognosis, indicating an increasing need to detect these mutations during routine laboratory analysis. DNA sequencing for the identification of these mutations is time-consuming and cost-intensive. This study aimed to establish rapid screening tests to identify mutations in DNMT3A and IDH1/2 that could be applied in routine laboratory procedures and that could influence initial patient management. Methods In this study we developed an endonuclease restriction method to identify the most common DNMT3A mutation (R882H) and an amplification-refractory mutation system (ARMS) to analyse IDH2 R140Q mutations. Furthermore, we compared these methods with HRM analysis and evaluated the latter for the detection of IDH1 mutations. Results Of 230 samples from patients with AML 30 (13%) samples had DNMT3A mutations, 16 (7%) samples had IDH2 R140Q mutations and 36 (16%) samples had IDH1 mutations. Sensitivity assays performed using serial dilutions of mutated DNA showed that ARMS analysis had a sensitivity of 4.5%, endonuclease restriction had a sensitivity of 0.05% and HRM analysis had a sensitivity of 5.9%–7.8% for detecting different mutations. HRM analysis was the best screening method to determine the heterogeneity of IDH1 mutations. Furthermore, for the identification of mutations in IDH2 and DNMT3A, endonuclease restriction and ARMS methods showed a perfect concordance (100%) with Sanger sequencing while HRM analysis showed a near-perfect concordance (approximately 98%). Conclusion Our study suggested that all the developed methods were rapid, specific and easy to use and interpret. HRM analysis is the most timesaving and cost

  1. The PneuCarriage Project: A Multi-Centre Comparative Study to Identify the Best Serotyping Methods for Examining Pneumococcal Carriage in Vaccine Evaluation Studies

    PubMed Central

    Satzke, Catherine; Dunne, Eileen M.; Porter, Barbara D.; Klugman, Keith P.; Mulholland, E. Kim

    2015-01-01

    Background The pneumococcus is a diverse pathogen whose primary niche is the nasopharynx. Over 90 different serotypes exist, and nasopharyngeal carriage of multiple serotypes is common. Understanding pneumococcal carriage is essential for evaluating the impact of pneumococcal vaccines. Traditional serotyping methods are cumbersome and insufficient for detecting multiple serotype carriage, and there are few data comparing the new methods that have been developed over the past decade. We established the PneuCarriage project, a large, international multi-centre study dedicated to the identification of the best pneumococcal serotyping methods for carriage studies. Methods and Findings Reference sample sets were distributed to 15 research groups for blinded testing. Twenty pneumococcal serotyping methods were used to test 81 laboratory-prepared (spiked) samples. The five top-performing methods were used to test 260 nasopharyngeal (field) samples collected from children in six high-burden countries. Sensitivity and positive predictive value (PPV) were determined for the test methods and the reference method (traditional serotyping of >100 colonies from each sample). For the alternate serotyping methods, the overall sensitivity ranged from 1% to 99% (reference method 98%), and PPV from 8% to 100% (reference method 100%), when testing the spiked samples. Fifteen methods had ≥70% sensitivity to detect the dominant (major) serotype, whilst only eight methods had ≥70% sensitivity to detect minor serotypes. For the field samples, the overall sensitivity ranged from 74.2% to 95.8% (reference method 93.8%), and PPV from 82.2% to 96.4% (reference method 99.6%). The microarray had the highest sensitivity (95.8%) and high PPV (93.7%). The major limitation of this study is that not all of the available alternative serotyping methods were included. Conclusions Most methods were able to detect the dominant serotype in a sample, but many performed poorly in detecting the minor

  2. A comparative approach for the investigation of biological information processing: An examination of the structure and function of computer hard drives and DNA

    PubMed Central

    2010-01-01

    Background The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Methods Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1) orthogonal uniqueness, (2) low level formatting, (3) high level formatting and (4) translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Results Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT) during high level formatting of the computer hard drive and the subsequent loading of an operating system (OS). Biological

  3. A Decade of Child-Initiated Family Violence: Comparative Analysis of Child-Parent Violence and Parricide Examining Offender, Victim, and Event Characteristics in a National Sample of Reported Incidents, 1995-2005

    ERIC Educational Resources Information Center

    Walsh, Jeffrey A.; Krienert, Jessie L.

    2009-01-01

    This article examines 11 years (1995-2005) of National Incident Based Reporting System data comparing victim, offender, and incident characteristics for two types of child-initiated family violence: child-parent violence (CPV) and parricide. The objective is to better understand the victim-offender relationship for CPV and parricide and to…

  4. Factors Predicting Satisfaction Judgments: A Comparative Examination.

    ERIC Educational Resources Information Center

    Emmons, Robert A.; And Others

    A number of psychological models may explain why people vary in their satisfaction with various life domains (e.g., family, or grades). Six of the models are: (1) positive affect (the degree to which one experiences joy or happiness in each life domain); (2) negative affect (unpleasant emotions associated with domains); (3) social comparison (how…

  5. Ear examination

    MedlinePlus

    King EF, Couch ME. History, physical examination, and the preoperative evaluation. In: Flint PW, Haughey BH, Lund LJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery . 6th ed. Philadelphia, ...

  6. [Examination procedures].

    PubMed

    Vassault, A; Arnaud, J; Szymanovicz, A

    2010-12-01

    Examination procedures have to be written for each examination according to the standard requirements. Using CE marked devices, technical inserts can be used, but because of their lack of homogeneity, it could be easier to document their use as a standard procedure. Document control policy applies for those procedures, the content of which could be as provided in this document. Electronic manuals can be used as well. PMID:21613016

  7. Acupuncture compared to oral antihistamine for type I hypersensitivity itch and skin response in adults with atopic dermatitis – a patient and examiner blinded, randomized, placebo-controlled, crossover trial

    PubMed Central

    Pfab, Florian; Kirchner, Marie-Therese; Huss-Marp, Johannes; Schuster, Tibor; Schalock, Peter C.; Fuqin, Jiang; Athanasiadis, Georgios I.; Behrendt, Heidrun; Ring, Johannes; Darsow, Ulf; Napadow, Vitaly

    2012-01-01

    Background Itch is the major symptom of atopic dermatitis (AD). Acupuncture has been shown to exhibit a significant effect on experimental itch in AD. Our study evaluated acupuncture and anti-histamine itch therapy (cetirizine) on type-I-hypersensitivity itch and skin reaction in AD using a patient and examiner blinded, randomized, placebo-controlled, crossover trial. Methods Allergen–induced itch was evaluated in 20 AD patients after several interventions in separate sessions: preventive (preceding) and abortive (concurrent) verum acupuncture (VAp and VAa), cetirizine (10mg, VC), corresponding placebo interventions (preventive, PAp, and abortive, PAa, placebo acupuncture; placebo cetirizine pill, PC), and a no-intervention control (NI). Itch was induced on the forearm and temperature modulated over 20 minutes, using our validated model. Outcome parameters included itch intensity, wheal and flare size, and the D2 Attention test. Results Mean itch intensity (SE: 0.31 each) was significantly lower following VAa (31.9) compared to all other groups (PAa: 36.5; VC: 36.8; VAp: 37.6; PC: 39.8; PAp: 39.9; NI: 45.7, p<0.05). There was no significant difference between VAp and VC (p>0.1), though both therapies were significantly superior to their respective placebo interventions (p<0.05). Flare size following VAp was significantly smaller (p=0.034) than PAp. D2 attention test score was significantly lower following VC compared to all other groups (p<0.001). Conclusions Both VA and cetirizine significantly reduced type-I-hypersensitivity itch in AD patients, compared to both placebo and NI. Timing of acupuncture application was important, as VAa had the most significant effect on itch, potentially due to counter-irritation and/or distraction. Itch reduction following cetirizine coincided with reduced attention. PMID:22313287

  8. Comparing the Trend of Physical Activity and Caloric Intake between Lipid-Lowering Drug Users and Nonusers among Adults with Dyslipidemia: Korean National Health and Nutrition Examination Surveys (2010–2013)

    PubMed Central

    Oh, Jin-Young; Chekal, Lan; Kim, Se-Won; Lee, Jee-Yon

    2016-01-01

    Background The purpose of this study was to compare the physical activity and caloric intake trends of lipid-lowering drug users with those of non-users among Korean adults with dyslipidemia. Methods This study was a repeated cross-sectional study with a nationally representative sample of 2,635 Korean adults with dyslipidemia based on the 2010–2013 Korea National Health and Nutrition Examination Survey. Physical activity was assessed using the International Physical Activity Questionnaire, and caloric intake was estimated through 24-hour dietary recall. All statistical analyses were conducted using IBM SPSS ver. 21.0 (IBM Co., Armonk, NY, USA). The changes in physical activity and caloric intake were investigated for lipid-lowering drug users and non-users using generalized linear models. Results The proportion of lipid-lowering drug users in the 2010–2013 survey population increased from 3.5% to 5.0% (P<0.001). Among adults of dyslipidemia, total of 1,562 participants (56.6%) reported taking lipid-lowering drugs, and 1,073 (43.4%) reported not taking lipid-lowering drugs. Drug users were more likely to be older and less educated and to have a diagnosis of diabetes, higher body mass index, and lower low density lipoprotein cholesterol level. Physical activity trends were tested separately for the lipid-lowering drug users and non-users, and a significant decrease was found among the drug users during the study period. Physical activity among the drug users in 2013 was 38% lower (1,357.3±382.7 metabolic equivalent [MET]; P for trend=0.002) than in 2010 (2,201.4±442.6 MET). In contrast, there was no statistically significant difference between drug users and non-users in the trend of caloric intake during the same period. Conclusion Physical activity significantly decreased among lipid-lowering drug users between 2010 and 2013, which was not observed among non-users. The importance of physical activity may need to be re-emphasized for lipid-lowering drug users

  9. Combining fs LA-ICP-MS, FIB and STXM-NEXAFS Methods for in-situ High-Spatial-Resolution Rock Varnish Analyses at the nm to µm Scale

    NASA Astrophysics Data System (ADS)

    Macholdt, D.; Andreae, M. O.; Jochum, K. P.; Kappl, M.; Kilcoyne, A. L. D.; Müller, M.; Pöhlker, C.; Stoll, B.; Weber, B.; Weigand, M.; Weis, U.

    2014-12-01

    Since over 200 years a number of studies debate the origin of the black or red, up to 250 µm thick coatings on desert rocks, referred to as rock varnish. The main components of varnish are poorly crystallized Mn and Fe oxides and clay minerals. Both biological and geological processes have been suggested for the genesis. We used a combination of 200 nm-femtosecond LA-ICP-MS, focused ion beam (FIB) slicing and scanning transmission X-ray microscopy - near edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS) for the high-spatial-resolution analysis of rock varnish from different locations (Negev, Israel; Knersvlakte, South Africa; Death Valley and Mojave Desert, California). Femtosecond LA-ICP-MS was used for the quantitative determination of major and trace element concentrations. In-situ measurements were conducted on thick sections with the advantages of non-matrix matched calibration, low ablation depth of ~10 µm for laser spot sizes of 10-40 µm and low detection limits of trace elements (< 0.01 - 1 µg g-1). Our results demonstrate that elements, such as Mn, Co, Pb, Ni and Cu, are highly enriched in varnish relative to the upper continental crust (up to a factor of 1000). Differences between varnishes from the various locations can be observed especially for the Mn/Fe (0.4-25.6), Mn/Ba (3-363) and Ni/Co (0.03-1.8) ratios. The REE patterns differ with LaN/YbN = 2-14 and positive Ce anomalies (Ce/Ce* = 1.1 - 9.1). To study the internal structures of varnish, 100 - 200 nm thick FIB slices were prepared to perform mappings of Fe, Mn, O, N, CO3, K, Ca, and C at the nm scale. In addition, the oxidation stages of Mn and Fe were identified. Banded internal structures of Mn and organic C can be observed in some samples, and cavities that are partly filled by C and Mn rich material. Some coatings tend to incorporate bigger dust grains (> 1 µm), while others only show very fine grained material (< 0.1 µm). The results of the combined microanalytical

  10. Examining the decomposed brain.

    PubMed

    MacKenzie, James Mackintosh

    2014-12-01

    Examination of the decomposed brain is a largely neglected area of forensic neuropathology. However, careful examination often yields valuable information that may assist in criminal proceedings. Decomposition encompasses the processes of autolysis, putrefaction, and decay. Most decomposed brains will be affected by both autolysis and putrefaction, resulting in a brain that may, at one end of the spectrum, be almost normal or, at the other end, pulpified, depending on the conditions in which the body remained after death and the postmortem interval. Naked eye examination may detect areas of hemorrhage and also guides appropriate sampling for histology. Histological appearances are often better than what would be predicted from the state of the brain. Histology often confirms macroscopic abnormalities and may also reveal other features such as ischemic injury. Silver staining demonstrates neuritic plaques, and immunocytochemistry for β-amyloid precursor protein and other molecules produces results comparable with those seen in well-preserved fixed brains. The usefulness of information derived from the examination of the decomposed brain in criminal proceedings is illustrated with 6 case reports drawn from the author's own practice. PMID:25384305

  11. The Effect of Senior Medical Student Tutors Compared to Faculty Tutors on Examination Scores of First- and Second-Year Medical Students in Two Problem-Based Learning Courses

    ERIC Educational Resources Information Center

    Sakai, Damon H; D'Eon, Marcel; Trinder, Krista; Kasuya, Richard T.

    2016-01-01

    At the University of Hawaii John A. Burns School of Medicine, senior medical student volunteers are used as tutors for some problem-based learning groups in both the first and second years. Previous studies on the advantages and disadvantages of student tutors compared to faculty tutors have been equivocal. This study expected to answer the…

  12. Examination Regimes and Student Achievement

    ERIC Educational Resources Information Center

    Cosentino de Cohen, Clemencia

    2010-01-01

    Examination regimes at the end of secondary school vary greatly intra- and cross-nationally, and in recent years have undergone important reforms often geared towards increasing student achievement. This research presents a comparative analysis of the relationship between examination regimes and student achievement in the OECD. Using a micro…

  13. Examining Sensory Quadrants in Autism

    ERIC Educational Resources Information Center

    Kern, Janet K.; Garver, Carolyn R.; Carmody, Thomas; Andrews, Alonzo A.; Trivedi, Madhukar H.; Mehta, Jyutika A.

    2007-01-01

    The purpose of this study was to examine sensory quadrants in autism based on Dunn's Theory of Sensory Processing. The data for this study was collected as part of a cross-sectional study that examined sensory processing (using the Sensory Profile) in 103 persons with autism, 3-43 years of age, compared to 103 age- and gender-matched community…

  14. Examination Management and Examination Malpractice: The Nexus

    ERIC Educational Resources Information Center

    Ogunji, James A.

    2011-01-01

    Examination malpractice or cheating has become a global phenomenon. In different countries of the world today, developed and developing, academic dishonesty especially cheating in examinations has heightened and taken frightening dimension. In many countries of the world this phenomenon has become a serious matter of concern that has left many…

  15. Comparing the efficacies of alginate, foam, hydrocolloid, hydrofiber, and hydrogel dressings in the management of diabetic foot ulcers and venous leg ulcers: a systematic review and meta-analysis examining how to dress for success.

    PubMed

    Saco, Michael; Howe, Nicole; Nathoo, Rajiv; Cherpelis, Basil

    2016-01-01

    Diabetic foot ulcers and venous leg ulcers are chronic wounds frequently encountered by dermatologists. Choosing appropriate wound dressings can effectively promote wound healing and potentially reduce morbidity and financial burden experienced by patients. The objective of our systematic review and meta-analysis was to evaluate wound healing efficacies of synthetic active dressings in diabetic foot ulcer and venous leg ulcer management. For data collection, PubMed, Embase, Cochrane Library, CINAHL, and clinicaltrials.gov online databases were searched from database inception to 10 May 2015. Fixed and random effects modeling were used to calculate pooled risk ratios for complete ulcer healing from pairwise dressing comparisons. The results of our review showed moderate-quality level evidence that hydrogels were more effective in healing diabetic foot ulcers than basic wound contact dressings (RR 1.80 [95% CI, 1.27-2.56]). The other dressing comparisons showed no statistically significant differences between the interventions examined in terms of achieving complete diabetic foot ulcer healing. Non-adherent dressings were more cost-effective than hydrofiber dressings for diabetic foot ulcers in terms of mean total cost per patient of the dressings themselves. All venous leg ulcer pairwise dressing comparisons showed equivalent dressing efficacies in terms of promoting complete ulcer healing. Overall, most synthetic active dressings and traditional wound dressings are equally efficacious in treating diabetic foot ulcers and venous leg ulcers. For treating diabetic foot ulcers, hydrogels are more efficacious than basic wound contact dressings, and non-adherent dressings are more cost-effective than hydrofiber dressings. Ultimately, dressing choice should be tailored to the wound and the patient. PMID:27617934

  16. Patient Eye Examinations - Adults

    MedlinePlus

    ... Examinations, Adults Patient Eye Examinations, Children Refractive Errors Scientists in the Laboratory Visual Acuity Testing Patient Eye Examinations, Adults × Warning message Automatic fallback to the cURL connection method kicked in to handle the request. Result code ...

  17. A comparative examination of the adsorption mechanism of an anionic textile dye (RBY 3GL) onto the powdered activated carbon (PAC) using various the isotherm models and kinetics equations with linear and non-linear methods

    NASA Astrophysics Data System (ADS)

    Açıkyıldız, Metin; Gürses, Ahmet; Güneş, Kübra; Yalvaç, Duygu

    2015-11-01

    The present study was designed to compare the linear and non-linear methods used to check the compliance of the experimental data corresponding to the isotherm models (Langmuir, Freundlich, and Redlich-Peterson) and kinetics equations (pseudo-first order and pseudo-second order). In this context, adsorption experiments were carried out to remove an anionic dye, Remazol Brillant Yellow 3GL (RBY), from its aqueous solutions using a commercial activated carbon as a sorbent. The effects of contact time, initial RBY concentration, and temperature onto adsorbed amount were investigated. The amount of dye adsorbed increased with increased adsorption time and the adsorption equilibrium was attained after 240 min. The amount of dye adsorbed enhanced with increased temperature, suggesting that the adsorption process is endothermic. The experimental data was analyzed using the Langmuir, Freundlich, and Redlich-Peterson isotherm equations in order to predict adsorption isotherm. It was determined that the isotherm data were fitted to the Langmuir and Redlich-Peterson isotherms. The adsorption process was also found to follow a pseudo second-order kinetic model. According to the kinetic and isotherm data, it was found that the determination coefficients obtained from linear method were higher than those obtained from non-linear method.

  18. Examination of the Five Comparable Component Scores of the Diet Quality Indexes HEI-2005 and RC-DQI Using a Nationally Representative Sample of 2–18 Year Old Children: NHANES 2003–2006

    PubMed Central

    Kranz, Sibylle; McCabe, George P.

    2013-01-01

    Obesity has been associated with low diet quality and the suboptimal intake of food groups and nutrients. Two composite diet quality measurement tools are appropriate for Americans 2–18 years old: the Healthy Eating Index (HEI) 2005 and the Revised Children's Diet Quality Index (RC-DQI). The five components included in both indexes are fruits, vegetables, total grains, whole grains, and milk/dairy. Component scores ranged from 0 to 5 or 0 to 10 points with lower scores indicating suboptimal intake. To allow direct comparisons, one component was rescaled by dividing it by 2; then, all components ranged from 0 to 5 points. The aim of this study was to directly compare the scoring results of these five components using dietary data from a nationally representative sample of children (NHANES 2003–2006, N = 5,936). Correlation coefficients within and between indexes showed less internal consistency in the HEI; age- and ethnic-group stratified analyses indicated higher sensitivity of the RC-DQI. HEI scoring was likely to dichotomize the population into two groups (those with 0 and those with 5 points), while RC-DQI scores resulted in a larger distribution of scores. The scoring scheme of diet quality indexes for children results in great variation of the outcomes, and researchers must be aware of those effects. PMID:24163762

  19. Examination Involving Students as Peer Examiners

    ERIC Educational Resources Information Center

    Ljungman, Anders G.; Silen, Charlotte

    2008-01-01

    The main interest in this article is students' involvement in assessment as a part of growth towards self-directedness in learning. In order to enhance students' development of autonomy in learning, a project involving "older" students as peer examiners for "younger" students was designed and carried out. Students in the sixth semester in a…

  20. Rod examination gauge

    SciTech Connect

    Bacvinskas, W.S.; Bayer, J.E.; Davis, W.W.; Fodor, G.; Kikta, T.J.; Matchett, R.L.; Nilsen, R.J.; Wilczynski, R.

    1991-12-31

    The present invention is directed to a semi-automatic rod examination gauge for performing a large number of exacting measurements on radioactive fuel rods. The rod examination gauge performs various measurements underwater with remote controlled machinery of high reliability. The rod examination gauge includes instruments and a closed circuit television camera for measuring fuel rod length, free hanging bow measurement, diameter measurement, oxide thickness measurement, cladding defect examination, rod ovality measurement, wear mark depth and volume measurement, as well as visual examination. A control system is provided including a programmable logic controller and a computer for providing a programmed sequence of operations for the rod examination and collection of data.

  1. Wood's lamp examination

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood's lamp examination To use the sharing features on this page, please enable JavaScript. A Wood's lamp examination is a test that uses ultraviolet ( ...

  2. Wood's lamp examination

    MedlinePlus

    A Wood's lamp examination is a test that uses ultraviolet (UV) light to look at the skin closely. ... Gebhard RE. Wood's light examination. In: Pfenninger JL, Fowler GC, eds. ... Care . 3rd ed. Philadelphia, PA: Elsevier Mosby; 2010:chap ...

  3. The neurological examination.

    PubMed

    April, R S

    1995-06-01

    This chapter describes methods of clinical history taking and examination of the PLDD candidate with lumbar radicular symptoms. It stresses features of the classical neurological examination of the back and lower extremities in a concise, systematic fashion. PMID:10150641

  4. Wood's Lamp Examination

    MedlinePlus

    ... dermatologists to assist in the diagnosis of various pigment and infectious disorders. The examination is performed in ... lamp. If a fungal or bacterial infection or pigment disorder is present, Wood's lamp examination can strengthen ...

  5. Physics 300 Provincial Examination.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    This document consists of the physics 300 provincial examination (English version), a separate "provincial summary report" on the results of giving the test, and a separate French language version of the examination. This physics examination contains a 53-item multiple choice section and an 12 item free response section. Subsections of the test…

  6. Skylab Dental Examination

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Skylab 2 Commander Charles Conrad is seen undergoing a dental examination by the Medical Officer, Joseph Kerwin in the Skylab Medical Facility. In the absence of an examination chair, Conrad simply rotated his body to an upside down position to facilitate the procedure.

  7. Computer grading of examinations

    NASA Technical Reports Server (NTRS)

    Frigerio, N. A.

    1969-01-01

    A method, using IBM cards and computer processing, automates examination grading and recording and permits use of computational problems. The student generates his own answers, and the instructor has much greater freedom in writing questions than is possible with multiple choice examinations.

  8. Examination Syllabus Comparisons.

    ERIC Educational Resources Information Center

    Mallatratt, J. L.

    1983-01-01

    A study was conducted based on an analysis of computer study courses leading to CSE and 0-level examinations. Several findings are discussed and questions about future developments are raised. Syllabus content (including history, hardware, basic computer science, programming, applications, and implications), format, and examinations are among the…

  9. Nondestructive examination development and demonstration plan

    SciTech Connect

    Weber, J.R.

    1991-08-21

    Nondestructive examination (NDE) of waste matrices using penetrating radiation is by nature very subjective. Two candidate systems of examination have been identified for use in WRAP 1. This test plan describes a method for a comparative evaluation of different x-ray examination systems and techniques.

  10. Genesis Preliminary Examination Plans

    NASA Technical Reports Server (NTRS)

    McNamara, K. M.; Stansbery, E. K.

    2004-01-01

    The purpose of preliminary examination of the Genesis sample collectors is to provide information on the condition and availability of collector materials to the science community as a basis for allocation requests. Similarly, the information will be used by the Genesis Sample Allocation sub-committee of CAPTEM to determine the optimum allocation scheme, and by the Genesis Curator to determine the processing sequence for allocation production. The plan includes a decision process and detailed examination and documentation protocol for whole arrays and individual collectors (wafers, concentrator targets, bulk metallic glass, gold foil, and polished aluminum). It also includes a plan for communicating the information obtained to the scientific community. The plan does not include a detailed plan for preliminary examination of the SRC lid foil collectors, the process for removal of individual collectors from their frames, or for the subsequent subdivision of collector materials for allocation.

  11. Witness Disclaiming During Examination.

    ERIC Educational Resources Information Center

    Stutman, Randall K.

    1986-01-01

    Supports research indicating that disclaimers have no effect on perceptions of source credibility. Reveals that frequency of disclaimer use was unrelated to subject-juror evaluations of witness credibility and testimony believability; females did not use more disclaimers than males during examination; and when females used disclaimers, they were…

  12. Scientist Examines Tornado Vortex

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In this Quick Time movie, a scientist examines what appears to be a tornado vortex (blue) coming out of a thunderstorm. The scientist uses 3D glasses to be able to see in 3 dimensions the different flows going out into the vortex. Earth science and weather studies are an important ongoing function of NASA and its affiliates.

  13. Curriculum Materials Examination System.

    ERIC Educational Resources Information Center

    Bond, David J.

    This document is a guideline for selection and evaluation of social studies curriculum materials developed by the Marin Social Studies Project. Questions are presented which will help in the examination of materials so that specific strengths and weaknesses in the materials can be determined. Consideration is given to the objectives and rationale…

  14. Partly Tailored Examinations

    ERIC Educational Resources Information Center

    Bedard, R.

    1974-01-01

    A type of examination in which additional questions are provided was used for Grade 12 Algebra and College 1 Introductory Calculus. An hypothesis was formulated that this procedure should reveal additional knowledge which whould be reflected in superior average scores for the class group. (Editor)

  15. Examination of the Mouth

    PubMed Central

    Kidd, H. R.

    1976-01-01

    In an examination of the mouth, a definite order should be followed, finishing with the presenting lesion. This article lists the most frequent local or systemic origins of oral lesions, and makes a plea for better recording of oral abnormalities. PMID:21308080

  16. A National Teacher Examination.

    ERIC Educational Resources Information Center

    Shanker, Albert

    1985-01-01

    The author calls for a tough national teacher examination to make teaching a genuine profession, to convince the public to pay teachers what they're worth, to empower teachers to make educational decision, to attract the best and brightest, and to ensure high quality education. Problems and prospects are discussed. (BS)

  17. [Anamnesis and clinical examination].

    PubMed

    Grüne, Stefan

    2016-01-01

    Anamnesis and clinical examination are the key functions of medical doctors to reveal the health problems of their patients. The correct assessment and handoff of these informations are the preconditions for a specific and cost saving diagnostic and therapy. The handoff can be made orally, in written form analogue or digital. The examination and documentation should be conducted in the order specified for every patient to avoid mistakes. New digital programs help to reach this aim but absorb the time of the medical doctor and depart him from the patients. Nurses and medical doctors should perform the rounds together for a mutually acquisition of information. This conduces towards a single-minded and cost-effectively diagnostic and therapy. PMID:26710199

  18. The neurologic examination.

    PubMed

    Averill, D R

    1981-08-01

    With practice, an orderly routine, and a basic understanding of neuroanatomy, the clinician should be able to tentatively localize lesions in the nervous system. Once the lesion is localized, ancillary studies are usually necessary to identify the disease process. In difficult cases when referral is impractical, an accurate description of the findings from the neurologic examination will greatly improve the value of consultation. PMID:6977917

  19. Visual examination apparatus

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A. (Inventor)

    1976-01-01

    An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location including a projection system for displaying to a patient a series of visual stimuli. A response switch enables him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system thereby provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

  20. The independent medical examination.

    PubMed

    Ameis, Arthur; Zasler, Nathan D

    2002-05-01

    The physiatrist, owing to expertise in impairment and disability analysis, is able to offer the medicolegal process considerable assistance. This chapter describes the scope and process of the independent medical examination (IME) and provides an overview of its component parts. Practical guidelines are provided for performing a physiatric IME of professional standard, and for serving as an impartial, expert witness. Caveats are described regarding testifying and medicolegal ethical issues along with practice management advice. PMID:12122847

  1. Near-edge X-ray absorption fine-structure spectroscopy of naphthalene diimide-thiophene co-polymers

    SciTech Connect

    Gann, Eliot; McNeill, Christopher R.; Szumilo, Monika; Sirringhaus, Henning; Sommer, Michael; Maniam, Subashani; Langford, Steven J.; Thomsen, Lars

    2014-04-28

    Near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy is an important tool for probing the structure of conjugated polymer films used in organic electronic devices. High-performance conjugated polymers are often donor-acceptor co-polymers which feature a repeat unit with multiple functional groups. To facilitate better application of NEXAFS spectroscopy to the study of such materials, improved understanding of the observed NEXAFS spectral features is required. In order to examine how the NEXAFS spectrum of a donor-acceptor co-polymer relates to the properties of the sub-units, a series of naphthalene diimide-thiophene-based co-polymers have been studied where the nature and length of the donor co-monomer has been systematically varied. The spectra of these materials are compared with that of a thiophene homopolymer and naphthalene diimide monomer enabling peak assignment and the influence of inter-unit electronic coupling to be assessed. We find that while it is possible to attribute peaks within the π* manifold as arising primarily due to the naphthalene diimide or thiophene sub-units, very similar dichroism of these peaks is observed indicating that it may not be possible to separately probe the molecular orientation of the separate sub-units with carbon K-edge NEXAFS spectroscopy.

  2. Comparing Composites.

    ERIC Educational Resources Information Center

    Mathras, Michael S.

    1993-01-01

    Presents an activity that models the work of chemical engineers. Students design, fabricate, and perform mechanical tests on plaster matrix composites and compare the strength to mass ratios of several products. (PR)

  3. Hot cell examination table

    DOEpatents

    Gaal, Peter S.; Ebejer, Lino P.; Kareis, James H.; Schlegel, Gary L.

    1991-01-01

    A table for use in a hot cell or similar controlled environment for use in examining specimens. The table has a movable table top that can be moved relative to a table frame. A shaft is fixedly mounted to the frame for axial rotation. A shaft traveler having a plurality of tilted rollers biased against the shaft is connected to the table top such that rotation of the shaft causes the shaft traveler to roll along the shaft. An electromagnetic drive is connected to the shaft and the frame for controllably rotating the shaft.

  4. Visual examination apparatus

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A. (Inventor)

    1973-01-01

    An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location is described. The apparatus includes a projection system for displaying to a patient a series of visual stimuli, a response switch enabling him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

  5. Examining hydrogen transitions.

    SciTech Connect

    Plotkin, S. E.; Energy Systems

    2007-03-01

    This report describes the results of an effort to identify key analytic issues associated with modeling a transition to hydrogen as a fuel for light duty vehicles, and using insights gained from this effort to suggest ways to improve ongoing modeling efforts. The study reported on here examined multiple hydrogen scenarios reported in the literature, identified modeling issues associated with those scenario analyses, and examined three DOE-sponsored hydrogen transition models in the context of those modeling issues. The three hydrogen transition models are HyTrans (contractor: Oak Ridge National Laboratory), MARKAL/DOE* (Brookhaven National Laboratory), and NEMS-H2 (OnLocation, Inc). The goals of these models are (1) to help DOE improve its R&D effort by identifying key technology and other roadblocks to a transition and testing its technical program goals to determine whether they are likely to lead to the market success of hydrogen technologies, (2) to evaluate alternative policies to promote a transition, and (3) to estimate the costs and benefits of alternative pathways to hydrogen development.

  6. Microstructural examination of

    NASA Astrophysics Data System (ADS)

    Fukuoka, C.; Yoshizawa, H.; Nakagawa, Y. G.; Lapides, M. E.

    1993-10-01

    Fatigue tests were performed to examine how microstructural conditioning influences crack initiation and propagation in SA508 class 3 low-carbon steel. A 3-mm-long crack was introduced in compact tension (CT) fatigue test specimens under four different loads in order to obtain crack tip plastic zones at different stress intensity factor ranges, ΔK = 18, 36, 54, and 72 MPa√m. The microstructure of the plastic zones around the crack tip were examined by trans- mission electron microscopy (TEM) and selected area electron diffraction (SAD). Micro- orientation of the dislocation cells in the plastic zones of all of the CT samples increased to 4 deg from the level of an as-received sample. Four-point bending fatigue tests were performed for plate shape samples with a large cyclic strain range. The SAD value of the bending samples was also 4 deg in the damaged area where cracks already initiated at an early stage of the fatigue process. These test results indicate that the microstructural conditioning is a prerequisite for the fatigue crack initiation and propagation in SA508. These observations may lead to better under- standing of how fatigue initiation processes transit to cracks.

  7. Comparative Religions.

    ERIC Educational Resources Information Center

    Cross, M. R.

    The two week course on comparative religions for secondary grade students consists of nine mini-packets. Course objectives for each student are to write a paragraph explaining the fundamental doctrines and concepts of the world religions that he chooses to study and to list the name and address of specific places of worship in the county in which…

  8. Quick Compare

    Energy Science and Technology Software Center (ESTSC)

    2000-01-10

    Quick Compare is a computer software application that helps a user quickly evaluate alternatives based on criteria and decide on a preferred alternative. The software leads a user through a simple process of defining alternatives and criteria. Then, one person or a group can score the alternatives based on the criteria. The results are immediately displayed in an easy-to-understand graphical output.

  9. Commercial Driver Medical Examinations

    PubMed Central

    Moffitt, Gary; Hanowski, Richard J.; Kales, Stefanos N.; Porter, Richard J.; Hegmann, Kurt T.

    2015-01-01

    Objective: The objective of this study was to assess relationships between body mass index (BMI) and comorbid conditions within a large sample of truck drivers. Methods: Commercial driver medical examination data from 88,246 commercial drivers between 2005 and 2012 were analyzed for associations between BMI, medical disorders, and driver certification. Results: Most drivers were obese (53.3%, BMI >30.0 kg/m2) and morbidly obese (26.6%, BMI >35.0 kg/m2), higher than prior reports. Obese drivers were less likely to be certified for 2 years and more likely to report heart disease, hypertension, diabetes mellitus, nervous disorders, sleep disorders, and chronic low back pain (all P < 0.0001). There are relationships between multiple potentially disqualifying conditions and increasing obesity (P < 0.0001). Morbid obesity prevalence increased 8.9% and prevalence of three or more multiple conditions increased fourfold between 2005 and 2012. Conclusions: Obesity is related to multiple medical factors as well as increasing numbers of conditions that limit driving certification. PMID:25710607

  10. Diagnosis and complementary examinations.

    PubMed

    Menghini, Moreno; Duncan, Jacque L

    2014-01-01

    Development of neuroprotective therapies requires an understanding of the mechanisms of retinal degeneration and a way to monitor response to treatment. With the increasing availability of genetic testing, precise characterization of the retinal degeneration phenotype is essential. This chapter covers standard and innovative diagnostic techniques and complementary examinations needed for the evaluation and treatment of retinal degenerative diseases. It aims to provide an overview of functional and structural diagnostic tools for the evaluation of retinal degenerative diseases, but is not intended as a comprehensive reference. Subjective assessment of visual function includes psychophysical tests, such as perimetry and microperimetry. Electrophysiology tests, such as the electroretinogram and electro-oculogram, are crucial in the assessment of retinal degenerative diseases and provide an objective assessment of global photoreceptor and retinal pigment epithelial cell function. Retinal structural measures are correlated with measures of retinal function to characterize the disease phenotype, including fundus photography using color, near-infrared, and autofluorescence imaging. Ocular perfusion can be assessed using fluorescein, indocyanine green, and noninvasive angiography. Optical coherence tomography provides information about retinal structure. Resolution of all images of retinal structure can be improved using adaptive optics, which permits visualization of individual photoreceptors and retinal pigment epithelial cells in the macula. PMID:24732761

  11. Examining Archean methanotrophy

    NASA Astrophysics Data System (ADS)

    Slotznick, Sarah P.; Fischer, Woodward W.

    2016-05-01

    The carbon isotope ratios preserved in sedimentary rocks can be used to fingerprint ancient metabolisms. Organic carbon in Late Archean samples stands out from that of other intervals with unusually low δ13C values (∼-45 to -60‰). It was hypothesized that these light compositions record ecosystem-wide methane cycling and methanotrophy, either of the aerobic or anaerobic variety. To test this idea, we studied the petrography and carbon and oxygen isotope systematics of well-known and spectacular occurrences of shallow water stromatolites from the 2.72 Ga Tumbiana Formation of Western Australia. We examined the carbonate cements and kerogen produced within the stromatolites, because methanotrophy is expected to leave an isotopic fingerprint in these carbon reservoirs. Mathematical modeling of Archean carbonate chemistry further reveals that methanotrophy should still have a discernible signature preserved in the isotopic record, somewhat diminished from those observed in Phanerozoic sedimentary basins due to higher dissolved inorganic carbon concentrations. These stromatolites contain kerogen with δ13Corg values of ∼ - 50 ‰. By microsampling different regions and textures within the stromatolites, we determined that the isotopic compositions of the authigenic calcite cements show a low degree of variation and are nearly identical to values estimated for seawater at this time; the lack of low and variable δ13Ccarb values implies that methanotrophy does not explain the low δ13Corg seen in the coeval kerogen. These observations do not support a methanotrophy hypothesis, but instead hint that the Late Archean may constitute an interval wherein autotrophs employed markedly different biochemical processes of energy conservation and carbon fixation.

  12. JPDR vessel steel examination

    SciTech Connect

    Corwin, W.R.; Broadhead, B.L.; Sokolov, M.A.

    1995-10-01

    There is a need to validate the results of irradiation effects research by the examination of material taken directly from the wall of a pressure vessel which has been irradiated during normal service. This task has been included with the HSSI Program to provide just such an evaluation of material from the wall of the pressure vessel from the JPDR. The JPDR was a small BWR that began operation in 1963. It operated until 1976, accumulating {approximately}17,000 h of operation, of which a little over 14,000 h were with the original 45-MWTh core, and the remaining fraction, late in life, with an upgraded 90-MWTh core. The pressure vessel of the JPDR, fabricated from A 302, grade B, modified steel with an internal weld overlay cladding of 304 stainless steel, is approximately 2 m ID and 73 mm thick. It was fabricated from two shell halves joined by longitudinal seam welds located 180{degrees} from each other. The rolling direction of the shell plates is parallel to the axis of the vessel. It operated at 273{degrees}C and reached a maximum fluence of about 2.3 x 10{sup 18} n/cm{sup 2} (> 1 MeV). The impurity contents in the base metal are 0.10 to 0.11% Cu and 0.010 to 0.017% P with a nickel content of 0.63 to 0.65%. Impurity contents of the weld metal are 0.11 to 0.14% Cu and 0.025 to 0.039% P with a nickel content of 0.59%.

  13. Trends in Comparative Education.

    ERIC Educational Resources Information Center

    Altbach, Philip G.

    1991-01-01

    Examines societal and academic factors influencing the development of comparative education since 1945, particularly in the United States. Discusses the dominance of structural functionalism and human capital theory in the 1960s, the recent shift to diverse research orientations and ideologies, and effects of institutional decline and…

  14. Stardust Interstellar Preliminary Examination

    NASA Astrophysics Data System (ADS)

    Westphal, A.; Stardust Interstellar Preliminary Examation Team: http://www. ssl. berkeley. edu/~westphal/ISPE/

    2011-12-01

    A. J. Westphal, C. Allen, A. Ansari, S. Bajt, R. S. Bastien, H. A. Bechtel, J. Borg, F. E. Brenker, J. Bridges, D. E. Brownlee, M. Burchell, M. Burghammer, A. L. Butterworth, A. M. Davis, P. Cloetens, C. Floss, G. Flynn, D. Frank, Z. Gainsforth, E. Grün, P. R. Heck, J. K. Hillier, P. Hoppe, G. Huss, J. Huth, B. Hvide, A. Kearsley, A. J. King, B. Lai, J. Leitner, L. Lemelle, H. Leroux, R. Lettieri, W. Marchant, L. R. Nittler, R. Ogliore, F. Postberg, M. C. Price, S. A. Sandford, J.-A. Sans Tresseras, T. Schoonjans, S. Schmitz, G. Silversmit, A. Simionovici, V. A. Solé, R. Srama, T. Stephan, V. Sterken, J. Stodolna, R. M. Stroud, S. Sutton, M. Trieloff, P. Tsou, A. Tsuchiyama, T. Tyliszczak, B. Vekemans, L. Vincze, D. Zevin, M. E. Zolensky, >29,000 Stardust@home dusters ISPE author affiliations are at http://www.ssl.berkeley.edu/~westphal/ISPE/. In 2000 and 2002, a ~0.1m2 array of aerogel tiles and alumi-num foils onboard the Stardust spacecraft was exposed to the interstellar dust (ISD) stream for an integrated time of 200 days. The exposure took place in interplanetary space, beyond the orbit of Mars, and thus was free of the ubiquitous orbital debris in low-earth orbit that precludes effective searches for interstellar dust there. Despite the long exposure of the Stardust collector, <<100 ISD particles are expected to have been captured. The particles are thought to be ~1μm or less in size, and the total ISD collection is probably <10-6 by mass of the collection of cometary dust parti-cles captured in the Stardust cometary dust collector from the coma of the Jupiter-family comet Wild 2. Thus, although the first solid sample from the local interstellar medium is clearly of high interest, the diminutive size of the particles and the low numbers of particles present daunting challenges. Nevertheless, six recent developments have made a Preliminary Examination (PE) of this sample practical: (1) rapid automated digital optical scanning microscopy for three

  15. Window comparator

    NASA Technical Reports Server (NTRS)

    Black, J. M. (Inventor)

    1977-01-01

    A window comparator is described, comprising two operational amplifiers, one with two feedback circuits, each feedback circuit having a diode connected to the amplifier output and poled for forward current conduction of opposite polarity, to provide an algebraic difference between an input signal and a selected set-point voltage. Differential input terminals of the second operational amplifier were connected to the separate feedback circuits of the first operational amplifier, one input terminal to the output of one diode, and the other to the output of the other diode. A selected window-width voltage was connected through a coupling resistor to one of the input terminals of the second operational amplifier to determine when the algebraic difference of the input signal and the setpoint voltage has exceeded a predetermined tolerance after that difference has changed signs.

  16. Comparing Newmark

    NASA Astrophysics Data System (ADS)

    Rodríguez-Peces, M. J.; García-Mayordomo, J.; Azañón-Hernández, J. M.; Jabaloy-Sánchez, A.

    2009-04-01

    selected La Paca rock-fall which was generated during La Paca 2005 earthquake (mbLg=4.7, IEMS=VI-VII). We have used a terrestrial laser scanner in order to obtain a high resolution digital elevation model of La Paca rock-fall area. Moreover, we have performed a back-analysis based on field data to estimate the static safety factor previous to the earthquake and the critical acceleration. Furthermore, we have selected a representative strong ground motion record for La Paca earthquake from international databases. The critical acceleration and the peak ground acceleration values obtained from the strong ground motion record allowed us to estimate the actual soil and topographic amplification effects. Finally, we have calculated analytically the real Newmark displacement at La Paca rock-fall and we have compared this displacement with our GIS estimation in order to improve the calibration of Newmark's method at the regional scale.

  17. The Chinese Cult of Examinations.

    ERIC Educational Resources Information Center

    Krebs, Sylvia H.

    1996-01-01

    Discusses how the cult of examinations continues to affect both teachers and students in China, and concludes that any serious reform of Chinese education depends on thoroughly rethinking the role of examinations in learning. (SR)

  18. Timing of the Medical Examination

    ERIC Educational Resources Information Center

    Christian, Cindy W.

    2011-01-01

    The medical examination of the sexually abused child may have evidentiary, medical, and therapeutic purposes, and the timing of the examination requires consideration of each of these objectives. In cases of acute sexual assault, emergent examinations may be needed to identify injury, collect forensic evidence, and provide infection and pregnancy…

  19. External Examining: Fit for Purpose?

    ERIC Educational Resources Information Center

    Bloxham, Sue; Price, Margaret

    2015-01-01

    In a context of international concern about academic standards, the practice of external examining is widely admired for its role in defending standards. Yet a contradiction exists between this faith in examining and continuing concerns about standards. This article argues that external examining rests on assumptions about standards which are…

  20. Examining Chemistry at CSE Level

    ERIC Educational Resources Information Center

    Yeoman, G. D.

    1972-01-01

    Discusses advantages and disadvantages of centralized examination system in assessing affective and other non-cognitive abilities of students in England. Describes three modes of teaching and assessment: (1) syllabus set and examined by Regional Boards; (2) school, or small group of schools, may set syllabus which is examined by the Board; (3)…

  1. Evaluation Theory Tree Re-Examined

    ERIC Educational Resources Information Center

    Christie, Christina A.; Alkin, Marvin C.

    2008-01-01

    When examining various evaluation prescriptive theories comparatively, we find it helpful to have a framework showing how they are related that highlights features that distinguish theoretical perspectives, thus a "theory" about theories. The evaluation theory tree that we presented in Alkin's recent book, "Evaluation Roots" [Eisner, E. (2004).…

  2. EXAMINATION OF SHIPPING PACKAGE 9975-05050

    SciTech Connect

    Daugherty, W.

    2014-11-06

    Shipping package 9975-05050 was examined in K-Area following its identification as a high wattage package. Elevated temperature and fiberboard moisture content are key parameters that impact the degradation rate of fiberboard within 9975 packages in a storage environment. The high wattage of this package contributes significantly to component temperatures. After examination in K-Area, the package was provided to SRNL for further examination of the fiberboard assembly. The moisture content of the fiberboard was relatively low (compared to packages examined previously), but the moisture gradient (between fiberboard ID and OD surfaces) was relatively high, as would be expected for the high heat load. The cane fiberboard appeared intact and displayed no apparent change in integrity relative to a new package.

  3. Physical examination during space flight

    NASA Technical Reports Server (NTRS)

    Harris, B. A. Jr; Billica, R. D.; Bishop, S. L.; Blackwell, T.; Layne, C. S.; Harm, D. L.; Sandoz, G. R.; Rosenow, E. C. 3rd

    1997-01-01

    OBJECTIVE: To develop techniques for conducting a physical examination in microgravity and to describe and document the physiologic changes noted with use of a modified basic physical examination. DESIGN: On the basis of data gathered from physical examinations on KC-135 flights, three physical variables were assessed serially in astronauts during two shuttle missions (of 8- and 10-day duration, respectively). Preflight, in-flight, and postflight examinations were conducted by trained physician-astronauts or flight surgeons, who used this modified examination. MATERIAL AND METHODS: Five male and two female crewmembers participated in the "hands-on" physical examination of all physiologic systems except the genitourinary system. Level of edema, intensity of bowel sounds, and peripheral reflexes were assessed and graded. RESULTS: This investigation identified unique elements of a physical examination performed during space flight that will assist in the development of standard methods for conducting examinations of astronauts in weightlessness. In addition, demonstrable changes induced by microgravity were noted in most physiologic systems examined. CONCLUSION: The data support the hypothesis that the microgravity examination differs from that conducted on earth or in a 1g environment. In addition, alterations in the physiologic response can be detected with use of hands-on technique. These data are invaluable in the development of optimal medical care for humans in space.

  4. ALTE Handbook of European Language Examinations and Examination Systems.

    ERIC Educational Resources Information Center

    Association of Language Testers in Europe, Cambridge (England).

    The handbook describes language examinations offered and examination systems administered by members of the Association of Language Testers in Europe (ALTE). An introductory section describes the rationale behind the founding of the organization, lists its 22 current members, and states its aims and objectives. Subsequent sections detail the…

  5. Pharmacological mydriasis and optic disc examination

    PubMed Central

    Kirwan, J.; Gouws, P.; Linnell, A.; Crowston, J.; Bunce, C.

    2000-01-01

    AIM—To determine whether pharmacological mydriasis leads to a significant difference in interobserver agreement of optic disc measurement compared with examination without mydriasis.
METHOD—A cross sectional study was performed with a pair of observers examining the optic disc of two randomised groups of patients, one group before diagnostic mydriasis, and the other afterwards. Horizontal and vertical disc diameters and cup/disc ratios were measured with a 78 dioptre lens. The study was repeated with another observer pair and two further groups of patients.
RESULTS—In study A 86 subjects were examined in total (52 without and 34 with mydriasis). In study B 87 subjects were examined (45 without and 42 with mydriasis). The 95% limits of agreement of the cup/disc ratio measurement differences were significantly larger without mydriasis (p<0.001 for all studies (F test)). For both studies examination after mydriasis gave significantly greater agreement for vertical and horizontal cup/disc ratios. The cases with good agreement (0.1 difference or better) for vertical cup/disc ratios were 37/52 (72%) and 34 /45 (76%) without mydriasis and 33/34 (97%) and 40/42 (95%) respectively with mydriasis. Similar differences were recorded for horizontal cup/disc ratios. Disc diameter measurement results showed similar differences in study A but were not affected by mydriasis in study B.
CONCLUSIONS—Examination of the optic disc without pharmacological mydriasis gives significantly poorer interobserver agreement. In this study, the mean 95% limits of agreement values for all cup/disc ratio values were 0.27 for examination without mydriasis and 0.13 for examination with mydriasis. A measure outside these limits would suggest a real difference. This study indicates that mydriasis is important for reproducible clinical examination in glaucoma.

 PMID:10906099

  6. Adenine adlayers on Cu(111): XPS and NEXAFS study.

    PubMed

    Tsud, Nataliya; Bercha, Sofiia; Ševčíková, Klára; Acres, Robert G; Prince, Kevin C; Matolín, Vladimír

    2015-11-01

    The adsorption of adenine on Cu(111) was studied by photoelectron and near edge x-ray absorption fine structure spectroscopy. Disordered molecular films were deposited by means of physical vapor deposition on the substrate at room temperature. Adenine chemisorbs on the Cu(111) surface with strong rehybridization of the molecular orbitals and the Cu 3d states. Annealing at 150 °C caused the desorption of weakly bonded molecules accompanied by formation of a short-range ordered molecular adlayer. The interface is characterized by the formation of new states in the valence band at 1.5, 7, and 9 eV. The present work complements and refines existing knowledge of adenine interaction with this surface. The coverage is not the main parameter that defines the adenine geometry and adsorption properties on Cu(111). Excess thermal energy can further rearrange the molecular adlayer and, independent of the initial coverage, the flat lying stable molecular adlayer is formed. PMID:26547179

  7. Adenine adlayers on Cu(111): XPS and NEXAFS study

    SciTech Connect

    Tsud, Nataliya; Bercha, Sofiia; Ševčíková, Klára; Matolín, Vladimír; Acres, Robert G.; Prince, Kevin C.

    2015-11-07

    The adsorption of adenine on Cu(111) was studied by photoelectron and near edge x-ray absorption fine structure spectroscopy. Disordered molecular films were deposited by means of physical vapor deposition on the substrate at room temperature. Adenine chemisorbs on the Cu(111) surface with strong rehybridization of the molecular orbitals and the Cu 3d states. Annealing at 150 °C caused the desorption of weakly bonded molecules accompanied by formation of a short-range ordered molecular adlayer. The interface is characterized by the formation of new states in the valence band at 1.5, 7, and 9 eV. The present work complements and refines existing knowledge of adenine interaction with this surface. The coverage is not the main parameter that defines the adenine geometry and adsorption properties on Cu(111). Excess thermal energy can further rearrange the molecular adlayer and, independent of the initial coverage, the flat lying stable molecular adlayer is formed.

  8. Examining the Pledge of Allegiance

    ERIC Educational Resources Information Center

    Martin, Leisa A.

    2008-01-01

    To prepare students for effective citizenship, the author examines the Pledge of Allegiance and explores its meaning, history, and role in American history. The author includes quotes presenting different views of the U.S. Pledge of Allegiance and examples of pledges from different countries. Teachers are encouraged to have students examine their…

  9. Assessment and Examinations in Armenia

    ERIC Educational Resources Information Center

    Bethell, George; Harutyunyan, Karine

    2008-01-01

    This profile describes traditional assessment practices in Armenia--many of which are typical of those formerly practised throughout the Soviet Union--and the ongoing efforts to reform formal examinations and school-based evaluation techniques. The extraordinarily high stakes associated with the examination currently used to select applicants for…

  10. Learning Communities: Examining Positive Outcomes

    ERIC Educational Resources Information Center

    Andrade, Maureen S.

    2008-01-01

    Learning communities, designed primarily to increase student persistence and academic achievement, are a common first-year initiative on university campuses. Assessments of learning communities frequently examine indicators that are easily quantifiable such as student persistence and academic achievement, but also examine factors thought to affect…

  11. Energy Education/Conservation Examination.

    ERIC Educational Resources Information Center

    Wert, Jonathan M.

    This examination is designed to measure the general awareness level of high school students, teachers, and citizens in the area of energy development and conservation. It is composed of 100 true-false statements concerning energy education concepts. A sample examinee answer sheet and an examiner key are included. Reproduction of the exam is…

  12. Investigating Phd Thesis Examination Reports

    ERIC Educational Resources Information Center

    Holbrook, A.; Bourke, S.; Lovat, T.; Dally, K.

    2004-01-01

    There has been a slow but steady accretion of findings on doctoral assessment and examination processes over the past decade and a half. The study of Australian PhD examination reported here draws on the written reports on 301 theses across all discipline areas. Text categories identified in the reports are linked to other data including the…

  13. Legal Challenges to Licensing Examinations.

    ERIC Educational Resources Information Center

    Pyburn, Keith M., Jr.

    1990-01-01

    Discrepancies between court and professional association views of licensing examinations are discussed. Litigation associated with Title VII of the Civil Rights Act of 1964 and constitutional law is considered. Courts should examine professional standards and apply those that are consistent with the court's determination of the proper…

  14. History of neurologic examination books.

    PubMed

    Boes, Christopher J

    2015-04-01

    The objective of this study was to create an annotated list of textbooks dedicated to teaching the neurologic examination. Monographs focused primarily on the complete neurologic examination published prior to 1960 were reviewed. This analysis was limited to books with the word "examination" in the title, with exceptions for the texts of Robert Wartenberg and Gordon Holmes. Ten manuals met the criteria. Works dedicated primarily to the neurologic examination without a major emphasis on disease description or treatment first appeared in the early 1900s. Georg Monrad-Krohn's "Blue Book of Neurology" ("Blue Bible") was the earliest success. These treatises served the important purpose of educating trainees on proper neurologic examination technique. They could make a reputation and be profitable for the author (Monrad-Krohn), highlight how neurology was practiced at individual institutions (McKendree, Denny-Brown, Holmes, DeJong, Mayo Clinic authors), and honor retiring mentors (Mayo Clinic authors). PMID:25829645

  15. The Impact of Assessment Tasks on Subsequent Examination Performance

    ERIC Educational Resources Information Center

    Van Gaal, Frank; De Ridder, Annemieke

    2013-01-01

    In this article, the impact of assessment tasks on examination result (measured by examination grades) is investigated. Although many describe the advantages of electronic assessment tasks, few studies have been undertaken which compare a traditional approach using a classical examination with a new approach using assessment tasks. The main…

  16. Clues for success on examinations.

    PubMed

    Roberts, G H; Davis, L G

    1988-01-01

    To sum up, the best advise is to manage time effectively and efficiently both before and during the examination. The days prior to the examination should be spent in a constructive manner allowing time for institution of good study habits, rest and relaxation. A state of good physical health should be maintained by regular dietary habits, sleep habits, and physical exercise. Students should do their homework and be positive about the outcome. Each individual can provide himself with the best opportunity to pass the examination. PMID:3194508

  17. 46 CFR 189.40-3 - Drydock examination, internal structural examination, cargo tank internal examination, and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... that operate in salt water must undergo two drydock and two internal structural examinations within any... operate in fresh water at least six months in every 12 month period since the last drydock examination... five year period regardless of the type of water in which they operate. No more than three years...

  18. 46 CFR 189.40-3 - Drydock examination, internal structural examination, cargo tank internal examination, and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... operate in fresh water at least six months in every 12 month period since the last drydock examination... that operate in salt water must undergo two drydock and two internal structural examinations within any... five year period regardless of the type of water in which they operate. No more than three years...

  19. 46 CFR 189.40-3 - Drydock examination, internal structural examination, cargo tank internal examination, and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... operate in fresh water at least six months in every 12 month period since the last drydock examination... that operate in salt water must undergo two drydock and two internal structural examinations within any... five year period regardless of the type of water in which they operate. No more than three years...

  20. 46 CFR 189.40-3 - Drydock examination, internal structural examination, cargo tank internal examination, and...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... that operate in salt water must undergo two drydock and two internal structural examinations within any... operate in fresh water at least six months in every 12 month period since the last drydock examination... five year period regardless of the type of water in which they operate. No more than three years...

  1. 46 CFR 189.40-3 - Drydock examination, internal structural examination, cargo tank internal examination, and...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... that operate in salt water must undergo two drydock and two internal structural examinations within any... operate in fresh water at least six months in every 12 month period since the last drydock examination... five year period regardless of the type of water in which they operate. No more than three years...

  2. Examining the Examiners: How Inexperienced Examiners Approach the Assessment of Research Theses

    ERIC Educational Resources Information Center

    Kiley, M.; Mullins, G.

    2004-01-01

    Earlier research by Mullins and Kiley (2002) [Studies in higher education, 27(4), 369-386] reported on the processes that experienced examiners go through when they assess research theses. Since that study two further studies have been undertaken, interviews with novice Australian examiners, reported here, and the analysis of approximately 100…

  3. Accuracy of NHANES periodontal examination protocols.

    PubMed

    Eke, P I; Thornton-Evans, G O; Wei, L; Borgnakke, W S; Dye, B A

    2010-11-01

    This study evaluates the accuracy of periodontitis prevalence determined by the National Health and Nutrition Examination Survey (NHANES) partial-mouth periodontal examination protocols. True periodontitis prevalence was determined in a new convenience sample of 454 adults ≥ 35 years old, by a full-mouth "gold standard" periodontal examination. This actual prevalence was compared with prevalence resulting from analysis of the data according to the protocols of NHANES III and NHANES 2001-2004, respectively. Both NHANES protocols substantially underestimated the prevalence of periodontitis by 50% or more, depending on the periodontitis case definition used, and thus performed below threshold levels for moderate-to-high levels of validity for surveillance. Adding measurements from lingual or interproximal sites to the NHANES 2001-2004 protocol did not improve the accuracy sufficiently to reach acceptable sensitivity thresholds. These findings suggest that NHANES protocols produce high levels of misclassification of periodontitis cases and thus have low validity for surveillance and research. PMID:20858782

  4. History of neurologic examination books

    PubMed Central

    2015-01-01

    The objective of this study was to create an annotated list of textbooks dedicated to teaching the neurologic examination. Monographs focused primarily on the complete neurologic examination published prior to 1960 were reviewed. This analysis was limited to books with the word “examination” in the title, with exceptions for the texts of Robert Wartenberg and Gordon Holmes. Ten manuals met the criteria. Works dedicated primarily to the neurologic examination without a major emphasis on disease description or treatment first appeared in the early 1900s. Georg Monrad-Krohn's “Blue Book of Neurology” (“Blue Bible”) was the earliest success. These treatises served the important purpose of educating trainees on proper neurologic examination technique. They could make a reputation and be profitable for the author (Monrad-Krohn), highlight how neurology was practiced at individual institutions (McKendree, Denny-Brown, Holmes, DeJong, Mayo Clinic authors), and honor retiring mentors (Mayo Clinic authors). PMID:25829645

  5. Examining Children's Models of Seed.

    ERIC Educational Resources Information Center

    Jewell, Natalie

    2002-01-01

    Reports research that examines children's models of seed. Explores the conceptions held by children (N=75) of germination and seed formation. Concludes that children hold a restricted meaning for the term 'seed'. (DDR)

  6. Examining Classroom Interactions & Mathematical Discourses

    ERIC Educational Resources Information Center

    Grant, Melva R.

    2009-01-01

    This investigation examined interactions in three classrooms to determine how they influenced Discourses related to mathematics learning and teaching. Mathematics education literature suggests that effective mathematics instruction includes mathematical Discourses. However, effective mathematical Discourses within mathematics classrooms vary…

  7. Manipulator comparative testing program

    SciTech Connect

    Draper, J.V.; Handel, S.J.; Sundstrom, E.; Herndon, J.N.; Fujita, Y.; Maida, M.

    1986-01-01

    The Manipulator Comparative Testing Program compared performance of selected manipulator systems under typical remote handling conditions. The site of testing was the Remote Operations and Maintenance Demonstration Facility operated by the Consolidated Fuel Reprocessing Program of the Oak Ridge National Laboratory. Three experiment examined differences among manipulator systems from the US and Japan. The manipulator systems included the Meidensha BILARM 83A, Central Research Laboratories' (CRL's) Model M-2, and GCA PaR systems Model 6000. Six manipulator and control mode combinations were evaluated: (a) the BILARM in master-slave mode without force reflection; (b) the BILARM in master-slave mode with force reflection; (c) the Model M-2 in master-slave mode without force reflection; (d) the Model M-2 in master-slave mode with force reflection; (e) the BILARM with switchbox controls; and (f) the PaR 6000 with switchbox controls. The experiments also examined differences between master-slave systems with and without force reflections, and differences between master-slave systems and switchbox-controlled systems.

  8. S8DR shield examination

    NASA Technical Reports Server (NTRS)

    Mason, D. G.; Mccurnin, W. R.

    1973-01-01

    The SNAP 8 developmental reactor lithium hydride shield was examined after being irradiated for over 7000 hours at relatively low temperature. A crack was located in the seam weld of the containment vessel, probably the result of hot short cracking under thermal stress. The LiH was visually examined at two locations and its appearance was typical of low temperature irradiated LiH. The adherence of the chrome oxide emittance coating was found to be excellent.

  9. Open-Book, Open-Web Online Examinations: Developing Examination Practices to Support University Students' Learning and Self-Efficacy

    ERIC Educational Resources Information Center

    Myyry, Liisa; Joutsenvirta, Taina

    2015-01-01

    The aim of this study was to investigate university students' experiences of open-book, open-web online examinations compared to traditional class examinations concerning preparing, responding, and learning. The data (N?=?110) were collected by an online survey from the university students who took an online examination. The students used…

  10. [Radiological examinations that have disappeared].

    PubMed

    Puylaert, Carl B A J; Puylaert, Julien B C M

    2011-01-01

    If a radiologist from 1950 could travel in time to 2011, he or she would be baffled to see how few of the radiological examinations he was familiar with, remain. We review the radiological examinations that have disappeared since X-rays were discovered, and include the causes of their disappearance. Barium studies have mainly been replaced by endoscopy, oral cholecystography by ultrasound, and intravenous urography by CT-scan. Angiography by means of a direct puncture of carotid artery and aorta has been replaced by Seldinger angiography. Pneumencephalography and myelography have been replaced by CT and MRI. Bronchography has been replaced by bronchoscopy and CT-scan, arthrography by MRI and arthroscopy. Many other radiological examinations have been replaced by ultrasound, CT or MRI. PMID:21447222