bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacteria Inactivation Using Low Power Pulsed Gliding Arc Discharges with Water Spray
Authors: Burlica R. , Grim R.G. , Shih K.‐Y. , Balkwill D. , Locke B. R.
Published: June 2010

Low temperature atmospheric pressure plasma (produced by a 250 mW pulsed gliding arc discharge) with water spray was utilized to inactivate bacteria colonies of Escherichia coli grown on the surface of an agar substrate. The pH, solution conductivity, H2O2, and nitrate concentrations were determined for air and argon carrier gases and different water flow rates. Control experiments conducted by spraying solutions of H2O2 in the absence of the discharge demonstrated that this chemical and its delivery by spraying account for approximately two to three orders of magnitude (depending upon bacterial loading) of the bacterial colony decontamination process for both carrier gases when bacteria are allowed to grow on the agar plate to form a biofilm. Reactive species or other factors arising from the gas flow from the plasma with the water spray caused bacteria inactivation of one to two orders of magnitude beyond those of spraying H2O2 alone.

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SDBS Modified XC‐72 Carbon for the Removal of Pb(II) from Aqueous Solutions
Authors: Shao Dadong , Jiang Zhongqing , Wang Xiangke
Published: June 2010

Sodium dodecylbenzene sulfonate (SDBS) is grafted on Vulcan XC‐72 carbon (XC‐72 carbon) using a plasma technique. The SDBS grafted XC‐72 carbon (XC‐SDBS) is characterized using XPS, UV‐Vis spectrophotometry, XRD, TGA‐DTA, SEM, and potentiometric acid‐base titration, respectively. The application of XC‐SDBS and XC‐72 carbon for the removal of Pb(II) ions from large volumes of aqueous solution is investigated. The results indicate that XC‐SDBS has much higher adsorption capacity than that of XC‐72 carbon. XC‐SDBS is a suitable material for the immobilization of heavy metal from large volumes of aqueous solutions in environmental pollution cleaning.

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Improved recess‐ohmics in AlGaN/GaN high‐electron‐mobility transistors with AlN spacer layer on silicon substrate
Authors: Arulkumaran Subramaniam , Ing Ng Geok , Sahmuganathan Vicknesh , Zhihong Liu , Maung Bryan
Published: June 2010

A systematic investigation of recess‐ohmic contact by inductively coupled plasma etching using four layers Ti/Al/Ni/Au metal on un‐doped AlGaN/GaN HEMT structure with a thin AlN spacer layer grown on silicon substrate were performed. Although the insertion of the thin AlN spacer layer effectively increases the two‐dimensional electron gas concentration and electron mobility due to the enhanced 2DEG confinement, it causes much difficulty in forming ohmic contacts. This problem has been resolved by recess‐ohmic approach prior to ohmic metalization. Improved HEMT characteristics were demonstrated by this technique. About 17.5% of increase in IDmax and 12.5% of increase in gmmax were observed by recess ohmics. This improved device performance is due to the reduction of Rc, Rd and Rs values by recess‐ohmics. From this investigation, we found that recess‐ohmics are essential to achieve high performance device characteristics in un‐doped AlGaN/GaN HEMTs with AlN spacer layer grown on Si substrate (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equivalent circuit model of a waveguide‐type Ge/Si avalanche photodetector
Authors: Dai Daoxin , Chen Hui‐wen , Bowers John E. , Kang Yimin , Morse Mike , Paniccia Mario J.
Published: June 2010

An equivalent circuit with an inductive element is presented for modelling a waveguide‐type Ge/Si avalanche photodetector (APD) with a separate‐absorption‐charge‐multiplication structure. A genetic algorithm optimization is used to extract the parameters for the elements included in the equivalent circuit by fitting the measured S22. Due to a resonance in the avalanche region, there is a peak enhancement for the frequency response of the APD when the bias voltage is relatively high. This is observed in the measurement and agrees with the theoretical calculation shown in this paper. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Corundum‐structured α‐phase Ga2O3‐Cr2O3‐Fe2O3 alloy system for novel functions
Authors: Kaneko Kentaro , Nomura Taichi , Fujita Shizuo
Published: June 2010

We propose a novel alloy system of oxide semiconductors promising for unique multifunctions, the corundum structured Ga2O3‐Cr2O3‐Fe2O3 alloys on sapphire substrates. With this system the optical band gap can be widely tuned from 2.2 to 5.3 eV while keeping the acceptable lattice mismatch. A key issue was to fabricate α‐Ga2O3 thin films, which has been recognized as a sub‐stable phase and there is a strongly tendency of growing at β‐Ga2O3 with traditional growth techniques, so the use of mist chemical vapor deposition (CVD) successfully overcame this problem and allows the growth of highly crystalline α‐Ga2O3. Following to our previous achievements of exploring the corundum structured Ga2O3‐Fe2O3 alloys, in this paper we have shown the growth of α‐Cr2O3 thin films and α‐phase Ga2O3‐Cr2O3 alloys. The results encourage the evolution of the Ga2O3‐Cr2O3‐Fe2O3 alloys but the existing problem of low solubility in water and high decomposition energy of the Cr precursor presently used, chromium acetylacetonate [(C5H8O2)3Cr], should be overcome for accelerated research of this promising new alloy system. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Al2O3 passivated InAlN/GaN HEMTs on SiC substrate with record current density and transconductance
Authors: Wang Han , Chung Jinwook W. , Gao Xiang , Guo Shiping , Palacios Tomas
Published: June 2010

In this work, we study the scaling characteristics of In0.17Al0.83N/GaN high electron mobility transistors (HEMTs). Scaling of both the DC and RF performance are studied as a function of InAlN thickness, gate recess and gate length to explore the design space of high frequency InAlN/GaN devices. Surface passivation by Al2O3 deposited using atomic layer deposition (ALD) is also investigated as an alternative to SixNy passivation. The fabricated devices give record maximum drain current density and transconductance (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of AlGaN‐based deep ultraviolet emitter active regions by temperature dependent time‐resolved photoluminescence
Authors: Garrett G. A. , Sampath A. V. , Shen H. , Wraback M. , Sun W. , Shatalov M. , Hu X. , Yang J. , Bilenko Y. , Lunev A. , Shur M. S. , Gaska R. , Grandusky J. R. , Schowalter L. J.
Published: June 2010

Temperature dependent time‐resolved photoluminescence is used to study the development of active regions for optoelectronic devices employing AlGaN nanostructures for deep‐UV emission. The changing importance of dislocation versus point defects and their relationship to different forms of carrier localization are discussed. The results presented suggest that AlGaN nanostructure development for deep‐UV emitters require both point defect/impurity suppression for improved efficiency and lower dislocation density for improved interface quality. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional theory study of lithium and fluoride doped boron nitride sheet
Authors: Anota Ernesto Chigo , Villanueva Martín Salazar , Cocoletzi Heriberto Hernández
Published: June 2010

We have performed first principles total energy calculations to investigate the structural and reactivity parameters of the lithium and fluoride doped graphene and boron nitride coronene‐like (C24H12) structure nanosheets. The exchange and correlations potential energies are treated in the local density approximation (LDA) within the parameterization of Perdew‐Wang (PWC) and the doubly polarized atomic base (DNP). The obtainment of non‐negative frequencies was the criterion for structural stability. Chemical potential, hardness and electrophilicy index, as well as bond length are reported. The B atom is substituted by Li and F atoms preserving the hexagonal structure, however, the stability is reached only with the Li atom. The covalence and the chemical reactivity are bigger when compared with the corresponding isolated systems. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The adsorption of an UV‐curable resin on hot‐dip galvanized steel: a ToF‐SIMS study
Authors: Marino P. , Lowe C. , Abel M.‐L. , Watts J. F.
Published: June 2010

The adsorption of an acrylated resin, the main component in a commercial UV‐cured coating, on hot‐dip galvanized steel (HDGS) has been studied. The aim of the work was to understand how the resin is adsorbed onto the different regions (aluminium‐rich and zinc‐rich) that are representative of the HDGS surface, in order to elucidate the mechanism of the HDGS/coating adhesion.

Time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) was employed to study the adsorption of the resin. Mass spectra and mass‐selected images were recorded in the high‐current bunched mode, using Bi3+ as the primary ion. Scatter ratio plots and relative mass selected images, were used to select the areas of interest for spectral reconstruction.

The adsorptions curves were best described by the Langmuir model, indicating that all the adsorption sites are equivalent. The adsorption of the resin leads to the formation of a monolayer on the surface of HDGS.

ToF‐SIMS ion selected images showed the presence of two well defined regions, aluminium‐rich regions and zinc‐rich regions. This distinction is not modified by the resin adsorption.

The adsorption of the resin was studied independently on aluminium‐rich regions and zinc‐rich regions. The adsorption curves indicate that the amount of adsorbed resin is almost identical in these two regions, with the formation of a resin monolayer in both cases. These results suggest that the resin/HDGS interaction is comparable in the aluminium‐rich and zinc‐rich regions. Copyright © 2010 John Wiley & Sons, Ltd.
Secondary ion yield enhancement in organic samples due to Au/Pt nanoparticle condensation and their substrate effects
Authors: Prabhakaran A. , Yunus S. , Wehbe N. , Bertrand P. , Delcorte A.
Published: June 2010

Upon atomic ion bombardment, metal nanoparticles at the surface of organic materials (polymers, additives, biomolecules) induce a strong increase of the analytically significant sample ion yields in secondary ion mass spectrometry. In order to unravel the physics behind the Metal Assisted SIMS (MetA SIMS) effect, this study focuses, first, on the comparison between thin layers of polystyrene (PS) on gold‐covered substrates and thick layers of PS covered with different thicknesses of Au. The evolutions of the characteristic fragment ion yields are almost identical up to 8 nm equivalent Au thickness but the yields of Au‐cationized oligomers are consistently one order of magnitude larger when gold is used as substrate. This difference might be due to the limited diffusion of PS on the Au condensates. Second, the effect of Au and Pt on the ion yield enhancement has been studied by casting thin layers of PS on Au and Pt‐covered Si substrates. The Au and Pt‐induced fragment ion yields evolve similarly with the metal thickness up to 6 nm. The yields of metal cationized oligomers, however, are 7–8 times lower in the case of Pt compared to that of Au. Tentative interpretation of this effect involves the nature of the Me‐PS bond and the abundance of the respective species. Copyright © 2010 John Wiley & Sons, Ltd.
The Pegase project, a new solid surface probe: focused massive cluster ion beams
Authors: Della‐Negra S. , Arianer J. , Depauw J. , Verkhoturov S. V. , Schweikert E. A.
Published: June 2010

The objective of this project is the development of the SIMS associated to a new probe of the solid: massive clusters consisting of 100–1000 bismuth or gold atoms. The systematic study of the ionic emission intensities as a function of the mass and energy of these projectiles showed that 100–200 qkeV is sufficient energy for the new probe. It is possible to obtain a time of flight (ToF) spectrum with a single impact. These spectra permit to characterize light molecules (MW∼ a few hundreds) with their fragments and intact molecular ion peaks. To analyze the surface, we propose to obtain cluster beams of 100–150 qkeV with a diameter of 10–100 µm, and to associate measurements of time of flight mass spectrometry with the detection of electron emission in order to locate the impact on the surface. We describe the simulation and the installation, on a 130 kV platform, of our column including a LMIS (Liquid Metal ion Source), lenses and Wien Filter, and of a focusing beam line made of an accelerating gap with its shield and a 130 kV insulator. We shall give the experimental beam specifications obtained with the massive cluster ion source Pegase for bismuth and gold. Copyright © 2010 John Wiley & Sons, Ltd.
Cluster primary ion sputtering: correlations in secondary ion intensities in TOF SIMS
Authors: Seah M. P. , Gilmore I. S.
Published: June 2010

A brief review is given of some of the behaviors of cluster primary ions in secondary ion mass spectrometry (SIMS). The increased secondary ion yields for cluster primary ions are covered as well as the raised sputtering threshold energies. For organic materials, the increase in intensity as the sputtering yield rises varies with the fragment mass through the spectrum. For Irganox 1010, the intensity of the deprotonated negative and the positive molecular ions increase as the square of the total ion yield. However, the intensity of intermediate fragments increase with a lower power, rising monotonically from unity at m/z ∼400 to 2 at the molecular ion. The constitution of the Irganox 1010 spectra for Ar+, Bi+, Bi$_{3}^{+}$ and Bi$_{5}^{+}$ may be described by a basic spectrum such as that for Ar+ and two further ‘spectra’ which are product terms that multiply the intensity to a power defined by the cluster primary ion species, cluster number and energy. This resolution of the spectra into three components may be translated, for example, to the published data for Si where, for Si$_{t}^{+}$ secondary ion clusters, the terms are very much simpler: one is a constant, the second is a single exponential term dependent of the energy‐deposition density, and the third is related to the cluster‐binding energy. Finally, for studying molecular structure, the use of cluster primary ions in G‐SIMS is outlined. Here, the cluster primary ions are critical for analyzing the weaker, high‐mass peaks. © Crown copyright 2010. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Effects of bias voltage on structure and properties of TiAl‐doped a‐C:H films prepared by magnetron sputtering
Authors: Pang Xianjuan , Hao Junying , Wang Peng , Xia Yanqiu , Liu Weimin
Published: June 2010

Hydrogenated TiAl‐doped a‐C:H films were deposited on Si substrates by middle frequency magnetron sputtering TiAl target in argon and methane gas mixture atmosphere. Effects of substrate bias voltage on structure and properties of the films, such as the surface morphology, hardness, chemical nature and bond types, were investigated by means of atomic force microscopy (AFM), XPS, Raman spectroscopy and nanoindentation. The friction and wear behaviors of the deposited films were characterized on an UMT‐2MT tribometer. SEM was utilized to analyze the wear scar on steel balls and debris after sliding on the deposited films under dry friction conditions. The results demonstrated that the film deposited at − 100 V exhibited low friction coefficient which is attributed to the easier formation of graphitized transfer layer. Copyright © 2010 John Wiley & Sons, Ltd.
A molecular dynamics study of a 5 keV C60 fullerene impact on a two‐component organic molecular sample
Authors: Ponomarev M. G. , Garrison B. J. , Vickerman J. C. , Webb R. P.
Published: June 2010

A study has been made to explore impact‐induced desorption of C60 fullerenes embedded in a benzene matrix as a model of matrix assisted secondary ion mass spectrometry. A fullerene concentration of about 0.5% was incorporated in a coarse‐grained benzene target and then struck by a 5 keV fullerene projectile. The response of the benzene target was compared with a pure benzene target to observe the effects of the embedded molecules on the matrix.

Three different trajectories were investigated. In the first, a single sputtered fullerene was ejected joined to a carbon atom from the projectile. In the second, an undamaged C60 was ejected, and in the third, no intact fullerenes were ejected. In all three cases, 4–6 fullerenes were pushed above the initial surface but were relocated into the crater rim, enriching the surface layer with the heavier and more strongly bound component.

It is observed that the sputtered fullerenes are ejected with a number of matrix molecules, and that there is a small decrease in the internal energy of the ejected fullerene that corresponds to the gradual separation of the surrounding matrix molecules from the larger molecule. This evaporative cooling may provide a potential benefit to Matrix Assisted SIMS. Copyright © 2010 John Wiley & Sons, Ltd.
Characterizing in situ Glycerophospholipids with SIMS and MALDI Methodologies
Authors: Passarelli M. K. , Winograd N.
Published: June 2010

The dual functionality of a C60+‐Q‐Star hybrid instrument allows for the examination of complex lipid profiles with both MALDI and SIMS methodologies.1 The difficulties associated with characterizing lipids in situ—isobaric interference and salt contamination—are discussed. The inherent advantages of both methodologies were used to deconvolute complex lipid spectra and establish characteristic fragmentation pathways. The high lateral resolution of SIMS allows for single cell images of aplysia californica neurons, while the established protocols were utilized to identify a major lipid component. Copyright © 2010 John Wiley & Sons, Ltd.
Trace metal contamination quantification on Silicon wafers using ToF‐SIMS: RSF determination from deposited droplet standards
Authors: Veillerot M. , Barnes J. P , Danel A.
Published: June 2010

ToF‐SIMS is now widely used in the microelectronic industry for contamination monitoring of silicon wafers, particularly for metallic elements. However, the accuracy of the technique is still questioned considering the discrepancies, sometimes up to a factor of 10, observable in existing Relative Sensitivity Factors (RSF) databases. A new standard preparation method using intentionally contaminated dried droplets is studied here. It is applied for Na, Fe, Zn and Mo on native oxide silicon wafers. Large‐area analysis (macroraster) is used to image the entire droplet residue of typically several mm in diameter overcoming heterogeneity or droplet movement difficulties. General agreement is obtained with existing data in the literature, however, with disparities still ranging around a factor of two are likely due to top surface ionization unsteadiness. Copyright © 2010 John Wiley & Sons, Ltd.
Analyses of the surfaces of concrete by Raman and FT‐IR spectroscopies: comparative study of hardened samples after demoulding and after organic post‐treatment
Authors: Chollet M. , Horgnies M.
Published: June 2010

Concrete surfaces were studied by two spectroscopic techniques, FT‐IR (in ATR mode) and Raman, to establish a nondestructive method to analyze the distribution of hydrated and organic phases. The surface composition of ordinary clinker, polished concrete, concrete after demoulding, and coated concrete as used in building construction was studied. The clinker's mineral phases and the polished concrete were first analyzed by Raman spectroscopy to determine a spectrum database of the specific phases located on the surface of the concrete. Then, both spectroscopic techniques were used to analyze, directly, the surface of hardened concrete after demoulding. No impact of roughness or porosity was highlighted using Raman spectroscopy; many cementitious, or hydrated phases (alite, belite, tricalcium aluminate, ferrite, portlandite and ettringite) were clearly identified. FT‐IR in ATR mode only identified some hydrated phases: portlandite and CaOSiO2H2O (CSH), but organic residues from the demoulding oil were characterized by this technique. Furthermore, the convenience of using these techniques together was tested by analyzing the composition of concrete surfaces coated by different organic post‐treatments. FT‐IR spectroscopy was useful to identify the main organic groups at the concrete surface, whereas Raman spectroscopy was especially able to characterize the mineral/hydrated phases under a thick post‐treatment layer (constituted of polyester varnish). Due to their own specificities, these complementary techniques should be used together to easily identify all the mineral phases and organic residues/coatings on concrete surfaces. Copyright © 2010 John Wiley & Sons, Ltd.
SIMS analysis of Rb‐doped hollow‐core photonic band‐gap silica fiber using a CAMECA 4550 instrument
Authors: Guryanov G. M. , Slepkov A. D. , Gaeta A. L. , Koch K. W.
Published: June 2010

A hollow‐core photonic band‐gap fiber exposed to Rb vapor was studied using quadrupole‐based SIMS. The Rb concentration along 30‐cm fibers was analyzed using a Cs+ beam. Effective charge compensation was obtained in the fiber cross‐section without using any metal coating. A low Rb detection limit of about 6 × 1015 atoms/cm3 was obtained in the silica microstructure region of the fiber. SIMS results revealed variations in the longitudinal distribution of Rb in fibers exposed to different loading conditions. Ion imaging of the fiber cross‐section using a Ga+ beam revealed the confinement of Rb atoms to the microstructured photonic region of the fiber, as opposed to the solid glass cladding. Copyright © 2010 John Wiley & Sons, Ltd.
Working group report of database construction of secondary electron yield
Authors: Nagatomi T. , Goto K. , Shimizu R.
Published: June 2010

In this report, we briefly introduce the plan of activities of the 141st Committee on Microbeam Analysis of Japan Society for the Promotion of Science (JSPS141)‐ a working group (WG) for the database construction of the secondary electron yield (SEY) (JSPS141‐WG‐SEY). The WG is established for the construction of databases of experimentally obtained SEYs and two physical constants to describe secondary electron (SE) emission with the help of Monte Carlo (MC) simulation. We also propose a new technique to measure the SEY of insulator by the charge amplification method. Copyright © 2010 John Wiley & Sons, Ltd.
Single molecule manipulation
Authors: Morgenstern Karina
Published: June 2010

The development of molecular switches on the single molecule level is a major challenge on the path towards incorporating molecules as building units into nanoelectronic circuits. With a scanning tunneling microscope (STM) it is possible to induce chemical reactions on a single molecule basis by electrons tunneling inelastically from the STM tip into a molecule. The method is based on high‐resolution imaging at low temperature (5 K) that allows us to identify different groups within the molecule. Chemical reactions are induced by injecting, selectively, electrons into specific parts of the molecule. The success of the manipulation is visualized in the recorded tunneling current during the manipulation and in STM images taken afterwards. We review, here, isomerization of individual molecules adsorbed on metal surfaces. For chlorobenzene and azobenzene derivatives, the effects of different substitutional groups and different substrates are explored. Copyright © 2010 John Wiley & Sons, Ltd.
Quantification of micro‐area analysis in SIMS
Authors: Seki Setsuko , Tamura Hifumi
Published: June 2010

Fabricating mesa structures with photolithography has been successful for depth profiling in SIMS for micrometer‐scale areas because it eliminates undesired ions originating from the surroundings of the analysis area. However, when we estimate dopant concentration from the SIMS depth profile for ion‐implanted samples using the mesa fabrication method, it is not appropriate to use a relative sensitivity factor (RSF). As an alternative to this conventional RSF method, the concentration was estimated by applying the Lindhard, Scharff, and Schiott (LSS) theory, that is, the distribution of ions penetrating into a solid are assumed to be described by a Gaussian approximation. We carried out the following process. First, the SIMS depth profile of the dopant ions with high sensitivity and high‐depth resolution for a mesa sample was measured. Second, the ΔRp value, the standard deviation of the projected range, was measured from the depth profile. Then, the peak concentration of the dopant ions was estimated from the formula using the measured ΔRp value mentioned above, assuming that implanting ions in a target material are distributed in a Gaussian distribution. This estimation method is a reasonable and practical way of obtaining dopant concentrations from a depth profile. Copyright © 2010 John Wiley & Sons, Ltd.
Structure and properties of chemically prepared nanographene islands characterized by scanning tunneling microscopy
Authors: Yamamoto Mayu , Obata Seiji , Saiki Koichiro
Published: June 2010

Single‐layer graphene islands with a typical diameter of several nanometers were grown on a Pt (111) substrate. Scanning tunneling microscopy (STM) analysis showed most of islands are hexagonally shaped and the zigzag‐type edge predominates over the armchair‐type edge. The apparent height at the atoms on the zigzag edge is enhanced with respect to the inside atoms for a small sample bias voltage, while such an enhancement was not observed at the atoms on the armchair edge. This result provides an experimental evidence of spatially (at the zigzag edge) and energetically (at the Fermi level) localized edge state in the nanographene islands, which were prepared chemically on Pt (111). Copyright © 2010 John Wiley & Sons, Ltd.
Nondestructive depth‐resolved chemical state analysis of (La,Sr)MnO3 film under high temperature
Authors: Shinoda Kozo , Suzuki Shigeru , Yashiro Keiji , Mizusaki Junichiro , Uruga Tomoya , Tanida Hajime , Toyokawa Hidenori , Terada Yasuko , Takagaki Masafumi
Published: June 2010

Fluorescence yield (FY) X‐ray absorption spectroscopic experiments with a grazing‐ exit geometry for detection of emitted fluorescence were carried out. The observed XAFS spectra provide the information about depth‐resolved chemical state in the surface layer of film materials through the take‐off angle dependence of the escape depth of the fluorescent X‐ray emitted from the sample. For La1−xSrxMnO3 films which are the oxygen electrode materials of a solid‐oxide fuel cell (SOFC), the Mn K XANES spectra were measured using undulator radiation at BL37XU in SPring‐8 synchrotron radiation facility. The results of the conventional FY‐XAS indicated differences due to distortion of MnO6 caused by different temperature, oxygen partial pressure p(O2) and voltage loading conditions in the spectrum profiles. From the results of the angle‐resolved measurements at 973 K in air, a depth‐dependent variation of the Mn K XANES profile in surface region of the film was observed. Though such depth‐dependence was also measured in case of lower p(O2) or voltage loading conditions at the same temperature, the absorbance proportion of absorbing bands contributing the change was different among the split 1s −>4p transition bands. These results indicate a difference in surface region caused by a difference between the surface and the inside of the film in the chemical potential of oxygen. Copyright © 2010 John Wiley & Sons, Ltd.
Investigating the tarnish and corrosion mechanisms of Chinese gold coins
Authors: Liang Chenghao , Yang Changjiang , Huang Naibao
Published: June 2010

In order to investigate the gold coin's tarnish mechanism, the tarnish and corrosion mechanism on Chinese gold coins was investigated by optical microscopy (OM), scanning electron microscope energy dispersive spectrometry (SEM‐EDS), electron microprobe analysis (EMPA), XPS and X‐ray diffraction (XRD). The results indicated that the tarnish on the gold coin was caused by silver on its surface. The main component of the tarnish stain on the gold coin was silver sulfide and silver sulfate. The stain and the contamination originate from the polishing procedure, which accelerated the tarnish process. Two measures can be taken to prevent the gold coin's tarnish. First, the mintage of gold and silver coins should be separated and, second, a chemical cleaning procedure should be introduced. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of surface roughness on near‐surface depth analysis from X‐ray reflectivity measurements
Authors: Fujii Yoshikazu
Published: June 2010

X‐ray reflectometry is a powerful tool for investigations of rough surfaces and interface structures. However, in previous studies, the calculation of the X‐ray reflectivity often show a strange effect where interference effects would increase at a rough surface. Here, we propose that this unexpected result of such calculations of the X‐ray reflectivity originates in a neglect of the effect of a decrease in the intensity of refracted X‐rays due to diffuse scattering at a rough surface and interface. In the present study, we present a new, accurate analysis of the X‐ray reflectivity from a multilayer surface taking into account roughness‐induced diffuse scattering. We calculated the X‐ray reflectivity for the W/Si system using a reduced Fresnel transmission coefficient at a rough surface and interface. The calculated reflectivity using this approach gave a physically reasonable result. A new approach using a reduced Fresnel transmission coefficient at a rough surface and interface allowed us to calculate physically reasonable values of the X‐ray reflectivity. Copyright © 2010 John Wiley & Sons, Ltd.
XPS study on band alignment at PtO‐terminated ZnO(0001) interface
Authors: Kim Taeyoung , Yoshitake Michiko , Yagyu Shinjiro , Nemsak Slavomir , Nagata Takahiro , Chikyow Toyohiro
Published: June 2010

The band alignment at the interface between Pt and O‐terminated ZnO(0001) was investigated by depositing Pt films on ZnO using X‐ray photoelectron spectroscopy and ultra violet photoelectron spectroscopy in an ultrahigh vacuum system. Angle‐resolved X‐ray photoelectron spectroscopy measurement showed the band was bent down by 0.06 eV at the ZnO(0001) surface. The binding energy of Zn 2p doublet shifted toward higher values by 0.37 eV when Pt was deposited on ZnO(0001). The work function of ZnO(0001) was 4.08 eV and the valence band maximum measured by UPS on the clean ZnO(0001) surface was 2.82 eV. As a result, the Schottky barrier height of Pt/ZnO(0001) was 0.72 eV in this experiment. Copyright © 2010 John Wiley & Sons, Ltd.
Construction of a pump‐probe system for observing time‐resolved sum frequency images
Authors: Hien Khuat Thi Thu , Miyauchi Yoshihiro , Mizutani Goro
Published: June 2010

We combined a pump‐probe technique with optical sum frequency microscopy, and demonstrated a time‐resolved SF intensity image observation of an HSi(111) surface in ultrahigh vacuum (UHV) conditions. After pump‐light irradiation of photon energy 2.33 eV, pulse duration ∼30 ps, and the width of the spot ∼304 µm, SF intensity image resonant to the SiH stretching vibration with IR probe wavenumber of 2085 cm−1 was darkened dramatically at 0 ps and then gradually recovered. Nonresonant SF signals with IR probe wavenumber of 2020 cm−1 increased at the probe delay time ∼0 ps, and then decreased with the life time of ∼1 ns. The width of the spatial profile of the nonresonant signal was at a minimum of ∼436 µm at the delay time 26 ps, and then increased to ∼673 µm at 930 ps. The origins of these behaviors of the SF intensity images are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Experimental and numerical analysis of sum frequency microscopic images of a H‐Si(111) 1 × 1 surface after IR light pulse irradiation
Authors: Miyauchi Y. , Sano H. , Okada J. , Yamashita H. , Mizutani G.
Published: June 2010

In this study, we have observed sum frequency (SF) images of a HSi(111) surface after IR light irradiation of pulse width ∼6 µs, and power from 11 to 13 mJ/pulse. After the IR light pulse irradiation, nonresonant SF signals appeared in the irradiated area. The width of the area emitting the nonresonant SF signal was sensitive to the power of IR light pulses. We compared the profile of the SF signal with that of the calculated hydrogen deficiency by using laser‐induced thermal desorption (LITD) model. The profiles of the calculated hydrogen deficiency were consistent with those of the observed nonresonant SF signal qualitatively. Copyright © 2010 John Wiley & Sons, Ltd.
Ellipsometric analysis of corrosion behavior of 3C magnesium alloy surface touched by simulated sweat
Authors: Zhang Shengtao , Wu Fengjing
Published: June 2010

As an optimum shell material, AZ80 magnesium alloys are widely applied in the 3C (computers, communications and consumer electronics) industries. The case of 3C products corroded by a sweaty hand has been simulated and the corrosion characters have been investigated by ellipsometric technology. Thickness variation of corrosive medium film on a Mg alloy surface was monitored. Surface structure of a corrosion layer was described with a three‐layer optical model (substrate—EMA—Cauchy) and thickness of each layer for different soaking time was obtained by fitting experimental data with the model. The corrosion product films with a refractive index of 1.45–1.62, loose corrosion product layer, can only provide limited protection to the substrate when a Mg alloy surface is corroded by sweat again. Copyright © 2010 John Wiley & Sons, Ltd.
Imaging analysis of cosmetic ingredients interacted with human hair using TOF‐SIMS
Authors: Kojima T. , Kitano H. , Niwa M. , Saito K. , Matsushita Y. , Fukushima K.
Published: June 2010

Human hair damage is caused by chemical treatments and various daily factors. A number of cosmetic ingredients have been developed to repair hair damage. It is important to know the localization of cosmetic ingredients distributed on human hair to understand the interaction mechanism of these ingredients with the hair.

In this work, the distribution of cosmetic ingredients on damaged hair was investigated using time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS). We examined the penetration of L‐theanine and the adsorption of cationic chitosan. The TOF‐SIMS imaging analysis revealed that L‐theanine penetrated deep and was distributed uniformly inside the damaged hair. Further, cationic chitosan was uniformly adsorbed on the hair surface. The analysis results showed that TOF‐SIMS is one of the most convenient methods to estimate the distribution of cosmetic ingredients on the hair. Copyright © 2010 John Wiley & Sons, Ltd.
Combined effect of autoclaving‐cooling and cross‐linking treatments of normal corn starch on the resistant starch formation and physicochemical properties
Authors: Kim Nam‐Hee , Kim Jung‐Hwan , Lee Suyong , Lee Heungsook , Yoon Jae‐Wook , Wang Ren , Yoo Sang‐Ho
Published: June 2010

Normal corn starch (NCS) was treated by both autoclaving‐cooling and cross‐linking to produce resistant starch (RS). The RS yield, crystalline structure, as well as other physicochemical properties of the modified starch were investigated. The yield of RS was 12.2% by four autoclaving‐cooling cycles, and it could be further increased up to 31.0% by the subsequent cross‐linking using sodium trimetaphosphate/sodium tripolyphosphate. The scanning electron microscopy images clearly illustrated that the granular structure of native starch was disrupted and a continuous network with irregular shape was formed after autoclaving‐cooling cycles. The subsequent chemical cross‐linking appeared to make the network structure more compact and dense. X‐ray diffraction patterns showed that B‐ and V‐types coexisted in all the modified corn starches, and all these modified starches exhibited very low viscosity which remained almost constant regardless of temperature changes.
Spatial learning‐induced increase in agmatine levels at hippocampal CA1 synapses
Authors: Leitch Beulah , Shevtsova Olga , Reusch Katharina , Bergin David H. , Liu Ping
Published: June 2010

Agmatine, a metabolite of L‐arginine, is considered as a novel putative neurotransmitter. It has been detected in axon terminals that synapse with pyramidal cells in the hippocampus, a brain region that is critically involved in spatial learning and memory. However, the role of agmatine in learning and memory is poorly understood. Recently, we demonstrated water maze training‐induced increases in tissue levels of agmatine in the CA1 subregion of the hippocampus. This finding has raised an issue whether an endogenous agmatine could directly participate in learning and memory processes as a neurotransmitter. In the present study, quantitative immunogold‐labeling and electron‐microscopical techniques were used to analyze the levels of agmatine in CA1 stratum radiatum (SR) terminals (n = 600) of male Sprague–Dawley rats that had been trained to find a hidden escape platform in the water maze (WM) task or forced to swim (SW) in the pool with no platform presented. Agmatine levels were significantly increased by ∼85% in the synaptic terminals of SR of trained WM group compared with the SW control group (all P < 0.001). These results, for the first time, demonstrate spatial learning‐induced elevation in agmatine levels at synapses in the hippocampus and provide evidence of its participation in learning and memory processing as a novel neurotransmitter. Synapse, 2011. © 2010 Wiley‐Liss, Inc.
Adapting to climate change to sustain food security
Authors: Ziervogel Gina , Ericksen Polly J.
Published: June 2010

Climate change poses considerable challenges to food security. Adapting food systems both to enhance food security for the poor and vulnerable and to prevent future negative impacts from climate change will require attention to more than just agricultural production. This article surveys the multiple components of food security, particularly those relating to access and utilization, which are threatened by the complex responses of food systems to the impacts of climate change. Food security can only be ensured and enhanced with a suite of interventions across activities, ranging from production to distribution and allocation. Although many studies have demonstrated the importance of policy and institutional interventions for ensuring food security after a shock, the climate change impacts and adaptation community have been slow to pick up on these lessons. This article pulls together lessons from the literature on the type of institutional interventions that could be strengthened to enable adaptation in the food system to buffer against climate change at multiple levels, from the local to the global level. Copyright © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Vulnerability and Adaptation to Climate Change > Institutions for Adaptation
Visual hallucinations
Authors: Collerton Daniel , Mosimann Urs Peter
Published: June 2010

Understanding of visual hallucinations is developing rapidly. Single‐factor explanations based on specific pathologies have given way to complex multifactor models with wide potential applicability. Clinical studies of disorders with frequent hallucinations—dementia, delirium, eye disease and psychosis—show that dysfunction within many parts of the distributed ventral object perception system is associated with a range of perceptions from simple flashes and dots to complex formed figures and landscapes. Dissociations between these simple and complex hallucinations indicate at least two hallucinatory syndromes, though exact boundaries need clarification. Neural models of hallucinations variably emphasize the importance of constraints from top down dorsolateral frontal systems, bottom up occipital systems, interconnecting tracts, and thalamic and brainstem regulatory systems. No model has yet gained general acceptance. Both qualitative (a small number of necessary and sufficient constraints) and quantitative explanations (an accumulation of many nonspecific factors) fit existing data. Variable associations of hallucinations with emotional distress and thought disorders across and within pathologies may reflect the roles of cognitive and regulatory systems outside of the purely perceptual. Functional imaging demonstrates that hallucinations and veridical perceptions occur in the same brain areas, intimating a key role for the negotiating interface between top down and bottom up processes. Thus, hallucinations occur when a perception that incorporates a hallucinatory element can provide a better match between predicted and actual sensory input than does a purely veridical experience. Translational research that integrates understandings from clinical hallucinations and basic vision science is likely to be the key to better treatments. WIREs Cogn Sci 2010 1 781–786

This article is categorized under:

Psychology > Perception and Psychophysics

Neuroscience > Cognition
Thiodipropionate ZnII Complexes: Synthesis, DFT Studies, and X‐ray Structure of [{Zn(phen)(H2O)}2(μ‐tdp)2]·3H2O
Authors: Grirrane Abdessamad , Álvarez Eleuterio , Pastor Antonio , Galindo Agustín
Published: June 2010

The zinc thiodipropionate complex [Zn(tdp)] (1) [tdp = S(CH2CH2COO)22–] was obtained by reaction of aqueous zinc dichloride with a 1:1 mixture of Na2CO3 and thiodipropionic acid. The bonding preferences of the tdp anion were studied by DFT methods. The reaction of 1 with o‐phenanthroline (phen) gave the dinuclear compound [{Zn(phen)(H2O)}2(μ‐tdp)2]·3H2O (2), which was characterized by X‐ray analysis.
Metallkomplexe von Farbstoffen, XII [1], Halbsandwich‐Komplexe von Ruthenium, Cobalt, Rhodium, Iridium mit Iminocarboxylaten aus 4‐(4′‐Nitrophenylazo)anilin (Disperse Orange 3) oder 4,4′‐Diaminoazobenzol und 2‐Oxocarboxylaten
Authors: Kühlwein Frank , Beck Wolfgang
Published: June 2010

The condensation of the amino groups of 4‐(4′‐nitrophenylazo)aniline or of 4,4′‐diaminoazo‐benzene with 2‐oxocarboxylates at chlorido bridged half‐sandwich complexes [(C5Me5)MCl2]2 (M = Rh, Ir), [(p‐cymene)RuCl2]2 or of [(C5Me5)(Co(CO)I2] provides a convenient way to attach azodyes to a metal ion via an 2‐iminocarboxylate ligand.
Effect of Essential Oils from Lippia geminata and Cymbopogon jwarancusa on In vitro Growth and Sporulation of Two Rice Pathogens
Authors: Deka Bhuyan P. , Chutia M. , Pathak M. G. , Baruah P.
Published: June 2010

Sheath blight and brown spot disease of rice caused by Rhizoctonia solani and Bipolaris oryzae causes significant yield loss in rice production worldwide. The present study was undertaken to examine the effect of two essential oils (EOs) from Lippia geminata and Cymbopogon jwarancusa on in vitro growth and sporulation of these two pathogens. The fungal radial growth was inhibited at very low concentration (25 ppm) of the EOs. Similarly, fungal spore production was also inhibited up to ≥80% at 500 ppm of EOs. However, fungal sporulation was completely retarded at 1,000 ppm of L. geminata EO. Very low oil concentrations (10 ppm) accelerated the radial growth (0–5 mm) and spore germination (3.5–8.5%) of the pathogens. At higher oil concentrations, the mycelial growth and spore productions were completely inhibited. The IC50 value of the EO of C. jwarancusa was 365.45 and 336.74 ppm and for L. geminata, it was 420.16 and 481.47 ppm against B. oryzae and R. solani, respectively. GC–MS analysis of the oils showed 54.36% piperitone and 30.86% α‐phellandrene as major compounds in C. jwarancusa whereas 25.9% geranial and 14.6% neral in L. geminata oil. Essential oils from Lippia geminata and Cymbopogon jwarancusa appear to be good candidates for the in vitro control of these two rice pathogens and can be successfully utilized in management strategies of pathogens in appropriate formulation.
Fluorescence and Bioluminescence Genetically Encoded Probes for Imaging Protein Conformational Changes and Interactions in Living Cells and Animals
Authors: Awais Muhammad
Published: June 2010

Rapid advancement in fluorescence and luminescence imaging technology is encouraging cell biologists to develop high-throughput assays for intracellular detection of bioactive small molecules, protein conformational changes, protein localization and dynamics, and measurement of protein—protein interactions in real time at the level of single living cells with high spatial and temporal resolution. In this report, we summarize the development of genetically encoded fluorescent and bioluminescent probes to study various molecular events in live cells and animals for potential drug candidates against different diseases.
Protecting Consumer Privacy in the Company'S Best Interest
Authors: Dolnicar Sara , Jordaan Yolanda
Published: June 2010

The increasing use of consumer databases by companies has led to increased levels of concern among consumers that their personal information may not be in safe hands once divulged to companies. A few studies have shown that consumer concern about information privacy may impact on consumer behaviour in ways directly opposed to the aims of the very marketing campaigns developed to increase sales. Should this indeed be the case, it would be in companies’ best interests to make protection of consumer privacy a priority. The aim of this paper is to investigate whether there is potential for such a market-driven mechanism of consumer privacy protection. An empirical survey within the Australian context was conducted to investigate the general level of concern among Australians about information privacy. Furthermore, associations between privacy concern levels and behaviour, as well as prior experiences with information privacy violations, are examined. Results indicate that: general privacy concern levels are high; associations exist between privacy concerns and protective behaviour; people tend to protect themselves in active ways, such as requesting the removal of information, rather than in passive ways, such as changing the distribution channel to reduce risk of privacy violation exposure; reactions to violations are typically very emotional and include behavioural intentions to take the matter to court.
English and Chinese? The Role of Consumer Ethnocentrism and Country of Origin in Chinese Attitudes towards Store Signs
Authors: Liu Fang , Murphy Jamie , Li Jianyao , Liu Xiangping
Published: June 2010

This article examines how consumer ethnocentrism (CE) relates to Chinese consumers’ evaluations of three store signs – Chinese name, English and Chinese name, and both languages along with the country of origin (COO) – for a hypothetical foreign bread shop. From an applied perspective, consumer attitudes and intention to purchase significantly favour the latter strategy. From an academic perspective, CE showed a significant relationship with bi-lingual signs. Compared to low ethnocentric consumers, high ethnocentric consumers had significantly less favourable attitudes and buying intentions towards bi-lingual signs. Ethnocentrism however, showed no relationship with attitudes and intentions towards a sign solely in Chinese. The study also found that COO can moderate the impact of CE on foreign brand evaluations, significantly so for a US brand but insignificant when the COO was Australia. The article closes with academic and applied implications for foreign brand naming strategies in China, as well as future research areas