bluuebunny/crossref_metadata_2025 huggingface dataset:
APPLICATION OF MICRO-PIXE IN ATMOSPHERIC ENVIRONMENTAL SCIENCE RESEARCH: ELEMENTAL MAPS IN ROOT OF SIEBOLD'S BEECH SEEDLING
Authors: SAITOH KATSUMI , WATANABE YOSHITO , IMASEKI HITOSHI , YUKAWA MASAE
Published: May 2007

Micro-beam scanning PIXE (micro-PIXE) and scanning transmission ion microscopy (STIM) were applied to measurement of one-year-old seedling root from a Siebold's beech (Fagus crenata Blume) tree. The beech seedling root samples were collected at the centerpiece of the Shirakami-Sanchi World Heritage Area during October 2001. Target samples for micro-PIXE and STIM analyses were transverse sections from tip, midpoint and root of the beech seedling root. We focused shedding light on tree root metabolism, and are to get a real image about the elemental distribution in the tree root. STIM images were similar to those generated using stereomicroscope and/or transmission microscopy. Real images in the form of elemental maps were obtained for nine elements: Na , Mg , Al , Si , P , S , Cl , K and Ca . Of these, typical elemental maps were Si and Ca , which were both concentrated in the epidermis. Si was prominent in the tip, while Ca was prominent in the root.
THE PIXE FACILITY AT TOKYO METROPOLITAN ISOTOPE RESEARCH CENTER
Authors: NAKAMURA MASARU , ISE HIROAKI
Published: May 2007

The PIXE facility at Tokyo Metropolitan Isotope Research Canter is described. This system allows for one-man total operation including accelerator control. A sample up to 100mm square can be set on the sample target which enable us to bombard arbitrary 36 points on the sample with proton. PIXE spectra are collected automatically using a computer which also controls the position of the sample holder. The facility is suitable for analysis of environmental samples and biological samples.
Preparation of Thin Polycarbonate Film and Its Application to PIXE Analysis of Anionic Elements in Water Samples
Authors: Yamazaki H. , Tsutsumi K. , Ishii K. , Matsuyama S. , Murozono K. , Inoue J. , Iwasaki S. , Orihara H.
Published: May 2007

A polycarbonate film of thin and uniform thickness was prepared. A casting solution for film-formation was made up by diluting a solution of poly (bisphenol A carbonate) in chloroform by a factor of two to three with benzene. A uniform film was created by dropping 0.2-0.3 cm3 of the casting solution slowly on a water surface within an aperture (20 mm diameter) of Mylar target frame floating on 50 wt% sucrose aqueous solution. Films of 0.14-0.27 mg/cm2 thickness thus prepared offer a good combination of mechanical strength and low continuum backgrounds. To test PIXE analysis of anionic species in water, targets containing SO 42-, Cr 2 O 72-, AsO 43-, and Ga 3+-internal standard were prepared by depositing 100 μl of the test solutions onto the polycarbonate film, and irradiated in vacuum by 3 MeV proton beams. The difference between the nominal and the analyzed concentrations seldom exceeded ± 15 % in the range from 10 to 2000 ppb.
PIXE ANALYSIS OF DRY DEPOSITION COLLECTED BY A CONTINUOUS SAMPLER USING A MODIFIED BETA-ATTENUATION DUST MONITOR
Authors: NAKAMURA MASARU , ISE HIROAKI
Published: May 2007

A high time-resolution system for dry deposition measurement was developed. This employed a modified beta-attenuation dust monitor and PIXE analysis in order to characterize the process of dry deposition. It was demonstrated that PIXE analysis can detect the presence of Al , Si , S and Fe in dry deposition samples for a one-hour sampling time.
Application of PIXE analysis to determination of trace elements in colonic tumor disease
Authors: Tsunoda S. , Sakurai S. , Matsuzawa M. , Yukawa M.
Published: May 2007

In order to investigate the validity of the cancer development, the presence of active oxygen need to be taken into account since active oxygen participates in the initiation and promotion of cancer. However, it is impossible to measure the amount of active oxygen in vivo directly. Therefore, the levels of trace elements such as Zn, Cu and Mn in enzyme which eliminates active oxygen were measured at each stage of cancer development by PIXE. The large differences between the normal mucosa and colonic adenoma in the amount of Zn, Cu and Mn within the enzyme eliminating free radicals were observed. There was a significant relationship among trace element levels, active oxygen and the development of tumor in connection with the levels of Zinc and Copper.
QUANTITATIVE ANALYSIS OF POWDERED BIO-SAMPLES BY THE STANDARD-FREE METHOD
Authors: SERA K. , FUTATSUGAWA S.
Published: May 2007

A Standard-free method, which has been developed by ourselves, was applied to powdered biomedical samples to which a conventional method of quantitative analysis, such as an internal standard method, can not be successfully applied. First, NIST-Bovine liver and NIES-rice targets, which are powdered as they are, were analyzed by the standard-free method and correct quantitative values of potassium and manganese concentration, which are consistent with those obtained by the conventional internal standard method, were obtained. Furthermore, for relative values of concentration of various elements, almost the best results we have ever had were obtained. Next, the present method has been successfully applied to a hard tissue sample (mouse bone), which is quite difficult to be accurately analyzed by the internal standard method. In order to solve the problem of falling off of powdered samples from a backing film, a carbon tape with an adhesive agent has been examined and found to be quite effective.
Nuclear Microprobe and Micro-PIXE Analysis of Thick Target: Program and Its Applications
Authors: DAI Zhongning , Ren Chaigang , Yang Fujia
Published: May 2007

PIXE (Particle Induced X-ray Emission), mainly Proton Induced X-ray Emission, has been developed into a well established technique for elemental analysis, especially for trace elemental analysis down to ppm or even ppb level. Nuclear Microprobe is a quickly developing technique around the world for 2 dimensional or even 3 dimensional element analysis if several nuclear analytical techniques, such as Rutherford backscattering spectrometry (RBS) can be available at the same time. The present resolution of NMP can be down to less than 1μm.

To thick target analysis, i.e., the energy loss effect and the consequent X-ray cross section Change with the depth can not be neglected, therefore we have to consider the process of particle interactions with atoms in detail. In this article, NMP (Nuclear Micro-Probe) and micro-PIXE analysis of thick target, which are mainly involved into the process of ions interaction with atoms, are reviewed on the basis of work what we have done at Fudan University. The software package TSPIXE (PIXE analysis of Thick Sample), which includes different versions for different applications, developed at Fudan University for quantitative analysis of thick target and simulation of PIXE and micro-PIXE spectra are described and its performance is demonstrated too. The TSPIXE package, which includes TSPIXE version I, version II, version III and TSμPIXE, was written in FORTRAN and C computer language and can be run at PC computer under MSDOS or WINDOWS environment. From the different demonstrations and applications we can see the package is very useful to quantitative analysis of thick samples and to understand the relationships between elemental X-ray intensity distributions and concentration distributions, sample structure, beam size and etc.
PIXE Analysis for Drainage from a Radioisotope Laboratory
Authors: TAKAHASHI Y. , YAMAZAKI H. , ISHII K. , MATSUYAMA S. , SATO T. , ORIHARA H. , JON G. C.
Published: May 2007

PIXE technique has been applied to quantitative analysis of thorium and uranium ions in drainage from a radioisotope laboratory of Tohoku University. Two kinds of targets were prepared and analyzed with an in-air vertical PIXE system of 3 MeV protons. The concentrations of thorium and uranium higher than 40 ppb were easily determined by 3-μC irradiation on targets which are made from a 0.12-ml solution containing Ga-internal standard evaporated on a hand-made polycarbonate film. Uranium(VI) ions in a 25-ml sample were preconcentrated into a thin uniform target containing Zr or Pd as an internal standard by means of dibenzyldithiocarbamate complexation with subsequent condensation into dibenzylidene-D-sorbitol gels, and low concentration of 10 ppb was precisely determined by PIXE measurement. This method does not work for concentrating thorium ions. The PIXE analysis for these two kinds of targets has good sensitivity and precision enough to determine concentrations of thorium and uranium lower than their permissible concentration limits in drainage from a radioisotope laboratory.
CHARACTERIZATION OF INSOLUBLE COMPONENTS IN FRESH SURFACE SNOW ON MOUNTAINS IN JAPAN
Authors: SAITOH K. , IWATA Y. , HIRANO K.
Published: May 2007

Fresh surface snow samples were collected at the summit or near the summit (700 - 1500 m altitude) of five mountains in Akita Pref., Japan. The elemental composition and particle shape of insoluble material in these snow samples was determined and/or observed by Particle Induced X-ray Emission (PIXE), a Scanning Electron Microscope (SEM) combined with Energy Dispersive X-ray (EDX) analysis. 21 kinds of elements for each mountain snow sample were determined by PIXE. Na , Mg , Al , Si , P , S , Cl , K , Ca , Ti and Fe were the major components in each of the mountain snow samples, and those in relative abundance were almost the same in each case. With the aid of SEM and EDX analysis, silicon-rich small sphere (spherule) particles and aggregates of car exhaust particles were observed in every mountain snow sample. These results are represented as insoluble components of clouds and provide important knowledge for the source and mechanism of snowfall and rainfall at the ground level.
QUANTITATIVE ANALYSIS OF POWDERED SAMPLES COMPOSED OF HIGH-Z ELEMENTS
Authors: SERA K. , FUTATSUGAWA S.
Published: May 2007

A method of quantitative analysis which is capable of analyzing powdered samples consisting of high-Z elements, such as ash, soil and aerosol, is developed. It is confirmed that an internal standard method using a powdered internal standard, which has almost the same particle size as that of a sample, gives quantitative values of concentration with satisfactory accuracy and reproducibility. It was successfully applied to standard samples such as NIST-Urban particulate matter (1648), GBW-Tibet soil (08302), BCR-City waste incineration ash (0497) and also to a practical fly-ash sample. As a result, it is found that the effect of self-absorption in the target is not negligible even for samples whose particle size is less than 4 μm, and a method of correcting it is established. Firstly, the effective thickness for self-absorption is estimated by comparing peak yields of a certain element for two measuring conditions of beam irradiation from the surface and from the back of the target. The correction factors can be estimated by using the effective thickness, values of concentration of principal elements and their photon absorption cross sections. For practical samples whose compositions are unknown, it is confirmed that accurate correction coefficients can be derived by carrying out an iterative calculation until a self-consistent solution between values of concentration of the main constituents and the correction factors is obtained.
OBSERVATION OF INTERFERENCE BETWEEN ATOMIC BREMSSTRAHLUNG AND NUCLEAR BREMSSTRAHLUNG
Authors: ISHII K. , SATOH T. , MATSUYAMA S. , YAMAZAKI H. , TOKAI Y. , SUGIMOTO A. , YAMAMOTO K.
Published: May 2007

An aluminum target was bombarded with 1.5 MeV protons and continuous x-rays were measured at the angles of 45°, 90° and 135° with respect to the beam direction. By investigating the shape of the x-ray energy spectrum, it was recognized that, the continuous x-rays below 12 keV are atomic bremsstrahlung (AB) and those of above 12 keV are nuclear bremsstrahlung (NB), and AB and NB are mingled in the energy region of around 12 keV The x-ray energy dependence of angular distributions presented well a change from the process of AB to that of NB in the continuous x-ray spectrum. Interference between AB and NB were discussed on the basis of PWBA theory. Continuous x-ray production cross sections were calculated on the basis of PWBA BEA and a semi-classical theory and compared with the experimental results. The theoretical prediction reproduced well the experimental cross sections over the wide range of 6 orders in magnitude and of 2 keV – 35 keV in the energy except for the energy region mingled with AB and NB. The ratio of the theoretical cross sections to the experimental ones showed an interference effect between AB and NB in their mingled region.
MICROPIXE INVESTIGATIONS: TIME SEQUENCING STUDIES IN DEGENERATIVE DISEASES
Authors: WATT FRANK , REN MINQIN , THONG PATRICIA P. S.
Published: May 2007

The simultaneously applied techniques of Particle Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Scanning Transmission Ion Microscopy (STIM), have been successful in mapping and quantifying trace elements during the progression of several human diseases, in particular those degenerative diseases which have a corresponding animal model. In atherosclerosis, iron has been shown to be present in increased concentrations at the early stage of lesion formation, and when the animal model has been kept anaemic, the artery wall shows a reduced uptake of iron and a delay in lesion formation compared with controls. In Parkinson's disease, there is also an increased concentration of iron in the substantia nigra region of the brain. Although the increase in bulk iron appears to lag behind the dopaminergic cell death, we have detected an increase in localized deposits of iron at the onset of cell death. These two results infer that iron may play a role in both diseases, perhaps through the mediation of free radicals. The induction of epilepsy through the injection of kainic acid has shown that the cell death is accompanied by an increase in calcium levels as early as one day after injection. The increase in calcium is consistent with activation of phospholipase A2and free radical damage.
BIO-PIXE IN MARINE SCIENCE - OTOLITHS AND PLANKTON
Authors: MALMQVIST KLAS G. , BÜLOW KARIN , ELFMAN MIKAEL , KRISTIANSSON PER , PALLON JAN , SHARIFF ASAD , LIMBURG KARIN E. , KARLSSON CHATARINA
Published: May 2007

Otoliths and phytoplanktons have been investigated using a nuclear microprobe. A brief description of sample preparation and irradiation conditions is given. The results indicate a great potential of the technique in marine sciences.
SIZE AND COMPOSITIONAL ANALYSES OF BIOLOGICALLY ACTIVE AEROSOLS FROM A CO2 AND DIODE LASER PLUME
Authors: MILLER ALAN E. , CAHILL THOMAS A.
Published: May 2007

Modern medical procedures, including laser surgery, can generate fine aerosols that may carry biologically active agents. With such procedures becoming more commonplace, it is evident that we need to look at the health implications on hospital staff when dealing with highly contagious patients with bacterial and/or viral infections, such as AIDS. The focus of this study is not to determine what portion that population is actually harmful, only to deduce what segment is still biologically active after vaporization from tissues. We have developed procedures to collect and analyze aerosols by size (from >10 μm to less than 0.07 μm) and by time (from minutes to ~ 4 hour increments). Health relevant size cuts for aerosols in a work environment have been adopted by the International Organization for Standardization and the Comite of European de Normalisation. We examined both the nature of the aerosols generated and the efficiency of hospital masks used by personnel in screening aerosols and simulated conditions under which aerosols might be inhaled. Four sets of data were recorded: Mask filtered physical, mask filtered biological, unfiltered physical and unfiltered biological. A combination of PIXE analyses on impactor and filter samples were matched with filters and strips plated on agarose plates and counted for colony forming units to determine the biologically active subset of the population.
ELEMENT ANALYSIS OF JAPANESE PAPER BY PIXE
Authors: SUZUKI TATSUYA
Published: May 2007

The Japanese papers, "washi", are made from the plants. Since the elements included in the washi have the informations of the raw material plants, there is potentiality of the identification of the production place by the element analysis of the washi. Three kinds of washi made of kozo, which have different habitats, were prepared. The elements in their washi were measured by the PIXE. It was confirmed that the amount of elements included in the washi depend on the habitats of their raw material plants.
CONDITIONS FOR GLOBAL OPTIMALITY OF QUADRATIC MINIMIZATION PROBLEMS WITH LMI CONSTRAINTS
Authors: JEYAKUMAR VAITHILINGAM , WU ZHIYOU
Published: May 2007

In this paper we present sufficient conditions for global optimality of non-convex quadratic programs involving linear matrix inequality (LMI) constraints. Our approach makes use of the concept of a quadratic subgradient. We develop optimality conditions for quadratic programs with LMI constraints by using Lagrangian function and by examining conditions which minimizes a quadratic subgradient of the Lagrangian function over simple bounding constraints. As applications, we obtain sufficient optimality condition for quadratic programs with LMI and box constraints by minimizing a quadrtic subgradient over box constraints. We also give optimality conditions for quadratic minimization involving LMI and binary constraints.
SYMMETRIES OF THE NEAR HORIZON OF A BLACKHOLE BY GROUP THEORETIC METHODS
Authors: MAHARANA K.
Published: May 2007

We use group theoretic methods to obtain the extended Lie point symmetries of the quantum dynamics of a scalar particle probing the near horizon structure of a black hole. Symmetries of the classical equations of motion for a charged particle in the field of an inverse square potential and a monopole, in the presence of certain model magnetic fields and potentials are also studied. Our analysis gives the generators and Lie algebras generating the inherent symmetries.
EFFECTIVE MASS HAMILTONIANS WITH LINEAR TERMS IN THE MOMENTUM: DARBOUX TRANSFORMATIONS AND FORM-PRESERVING TRANSFORMATIONS
Authors: SCHULZE-HALBERG AXEL
Published: May 2007

We define form-preserving transformations and Darboux transformations for time-dependent, effective mass Hamiltonians with additional linear terms. We give reality conditions for both transformations, guaranteeing the transformed potential to be real-valued. We further show that our form-preserving transformation preserves normalizability of the Schrödinger wave function. Our results generalize all former results on form-preserving transformations and Darboux transformations for the time-dependent Schrödinger equation. This paper is a sequel of Refs. 16–18.
COLOR-FLAVOR LOCKED STRANGELETS IN A QUARK MASS DENSITY-DEPENDENT MODEL
Authors: WEN X. J. , PENG G. X. , SHEN P. N.
Published: May 2007

The color-flavor locked (CFL) phase of strangelets is investigated in a quark mass density-dependent model. Parameters are determined by stability arguments. It is concluded that three solutions to the system equations can be found, corresponding, respectively, to positively charged, negatively charged, and nearly neutral CFL strangelets. The charge to baryon number of the positively charged strangelets is smaller than the previous result, while the charge of the negatively charged strangelets is nearly proportional in magnitude to the cubic-root of the baryon number. However, the positively charged strangelets are more stable compared to the other two solutions.
INTERSECTING CONNES NONCOMMUTATIVE GEOMETRY WITH QUANTUM GRAVITY
Authors: AASTRUP JOHANNES , GRIMSTRUP JESPER MØLLER
Published: May 2007

An intersection of noncommutative geometry and loop quantum gravity is proposed. Alain Connes' noncommutative geometry provides a framework in which the Standard Model of particle physics coupled to general relativity is formulated as a unified, gravitational theory. However, to this day no quantization procedure compatible with this framework is known. In this paper we consider the noncommutative algebra of holonomy loops on a functional space of certain spin-connections. The construction of a spectral triple is outlined and ideas on interpretation and classical limit are presented.
KÄHLER STABILIZED, MODULAR INVARIANT HETEROTIC STRING MODELS
Authors: GAILLARD MARY K. , NELSON BRENT D.
Published: May 2007

We review the theory and phenomenology of effective supergravity theories based on orbifold compactifications of the weakly-coupled heterotic string. In particular, we consider theories in which the four-dimensional theory displays target space modular invariance and where the dilatonic mode undergoes Kähler stabilization. A self-contained exposition of effective Lagrangian approaches to gaugino condensation and heterotic string theory is presented, leading to the development of the models of Binétruy, Gaillard and Wu. Various aspects of the phenomenology of this class of models are considered. These include issues of supersymmetry breaking and superpartner spectra, the role of anomalous U(1) factors, issues of flavor and R-parity conservation, collider signatures, axion physics, and early universe cosmology. For the vast majority of phenomenological considerations the theories reviewed here compare quite favorably to other string-derived models in the literature. Theoretical objections to the framework and directions for further research are identified and discussed.
ELASTIC AND INELASTIC SCATTERING OF POSITRONS BY POTASSIUM ATOMS
Authors: EL-BAKRY SALAH YASEEN
Published: May 2007

The investigations of the elastic and inelastic collisions of positrons with potassium atoms, K (1s2, 2s2, 2p6, 3s2, 3p6, 4s), are presented. The potassium target atoms are described using Clementi–Roetti wavefunctions within the framework of the one-valence-electron model. The total cross-sections which correspond to eight partial cross-sections are calculated at 34 values of the incident energy [Formula: see text] using the coupled-static approximation. The resulting total elastic, ground- and excited-positronium formation cross-sections are compared with experimental results and those calculated by other authors. In the vicinity of 6 eV, and consistent with the measurements of Parikh et al.,2our total cross-section displays a pronounced peak. We support the conclusion of McAlinden et al.15and Hewitt et al.14that above about 4 eV, positronium formation is mainly into excited states. Good agreement is obtained with the total cross-section measurements of Kwan et al.1and Parikh et al.2Positronium formation is not important above about 50 eV.
INTEGRABLE COUPLINGS OF THE TC HIERARCHY AND ITS HAMILTONIAN STRUCTURE
Authors: LI ZHU , ZHANG YUJUAN , DONG HUANHE
Published: May 2007

Integrable couplings of the TC hierarchy is obtained by use of the new subalgebra of the loop algebra Ã3, then the Hamiltonian structure of the above system is given by the quadratic-form identity.
QUANTUM STATES WITH CONTINUOUS SPECTRUM FOR THE TIME-DEPENDENT HARMONIC OSCILLATOR WITH A SINGULAR PERTURBATION
Authors: CHOI JEONG RYEOL , OH JUN-YOUNG
Published: May 2007

The quantum states with continuous spectrum for the time-dependent harmonic oscillator perturbed by a singularity are investigated. This system does not oscillate while the system that has discrete energy eigenvalue does. Exact wave functions satisfying the Schrödinger equation for the system are derived using invariant operator and unitary operator together.
EGALITARIAN DISTRIBUTIONS IN COALITIONAL MODELS
Authors: ARIN J.
Published: May 2007

The paper presents a framework in which the most important single-valued solutions in the literature of TU games are jointly analyzed. None of the main results is original.
FUZZY VOTERS, CRISP VOTES
Authors: CÔRTE-REAL PAULO P.
Published: May 2007

In a binary choice voting scenario, voters may have fuzzy preferences but are required to make crisp choices. In order to compare a crisp voting procedure with more general mechanisms of fuzzy preference aggregation, we first focus on the latter. We present a formulation of strategy-proofness in this setting and study its consequences. On one hand, we achieve an axiomatic recommendation of the median as the aggregation rule for fuzzy preferences. On the other hand, we present conditions under which strategic concerns imply the optimality of a crisp voting procedure and argue that there is a potential gain in the integration of the preference and choice aggregation programs — namely that an underlying fuzzy preference structure may also help inform the selection of a choice aggregation rule.
NITRILES ADSORBED ON Si(001) AT 300 K STUDIED VIA SYNCHROTRON RADIATION CORE-ELECTRON SPECTROSCOPIES
Authors: ROCHET FRANÇOIS , BOURNEL FABRICE , CARNIATO STEPHANE , DUFOUR GEORGES , GALLET JEAN-JACQUES , ILAKOVAC VITA , LE GUEN KARINE , RANGAN SYLVIE , KUBSKY STEPHAN , SIROTTI FAUSTO
Published: May 2007

This paper focuses on the use and value of XPS and NEXAFS spectroscopies to unveil the nature of the chemical bond of various bifunctional nitrile molecules adsorbed on Si (001) 2×1 at 300 K. The adsorption modes are also discussed in the light of recent theoretical publications devoted to optimized geometries and reaction paths of these molecules on Si (001).
CYCLOADDITION REACTION BETWEEN ORGANIC MOLECULES AND Si(100) AND ELECTRONIC PROPERTIES OF ADSORBED MOLECULES
Authors: YOSHINOBU J. , UMEYAMA H. , NAGAO M. , OGUCHI K. , MUKAI K. , YAMASHITA Y.
Published: May 2007

The mechanism of cycloaddition reaction between ethylene and the Si dimer on Si (100) is discussed from our recent experimental results using high-resolution electron energy loss spectroscopy and valence photoelectron spectroscopy at ~50 K. The weakly adsorbed π-complex state is identified as a precursor for di-σ bond formation and the activation barrier is roughly estimated to be ~0.2 eV. A different reaction route may exist since a di-σ species is also observed at low temperature. Using cycloaddition reaction, unsaturated organic molecules are chemically attached to the dimer on Si (100), and the adsorbed species are relatively stable. Thus, scanning tunneling spectroscopy (STS) measurements of a single adsorbed molecule can be carried out at room temperature. We report the STS results of 2-butyne adsorbed on Si (100).
TWO-DIMENSIONAL MICROMETER-SIZED SINGLE-CRYSTALLINE Si THIN NANOSHEETS DERIVED FROM CaSi2
Authors: NAKANO HIDEYUKI , ISHII MASAHIKO , NAKAMURA HIROSHI
Published: May 2007

CaSi 2 with a Zintl phase was investigated for the synthesis of nanosheets due to its facile formation of Ca 2+( Si -)2. The anionic Si - is isoelectronic with V elements and forms anion partial lattices of corrugated layers like As. The Ca 2+ planar layers are sandwiched between the anion layers. This CaSi 2 precursor was dispersed in a tetrabutylammonium hydroxide (TBA+OH-), and the resulting solid was lamellar Si · TBA composite. Finally, simple heat treatment of the lamellar precursor at 950°C under vacuum leads to Si nanosheets. The Si nanosheets grown along [111] direction has lateral dimensions up to several hundreds of microns, and thickness of 20–70 nm. Photoluminescence measurements reveal that the present Si nanosheets have visible emission bands ranging from green to red.
REVERSAL OF DOPING INDUCED ENERGY LEVEL SHIFT IN ORGANIC SEMICONDUCTORS
Authors: DING HUANJUN , GAO YONGLI
Published: May 2007

We have investigated the electronic structure of the interface formed by depositing Au on Cs -doped and Na -doped tris(8-hydroxyquinoline) aluminum (Alq) film using ultraviolet and X-ray photoemission spectroscopy (UPS and XPS). The initial Au deposition quenches the Al q gap state caused by the alkali metal doping. Further Au depositions shift gradually the energy levels opposite to that induced by Cs doping, especially the highest occupied molecular orbital (HOMO) that shows approximately full recovery to the pristine Al q position. However, the recovery is only partial for other levels, most noticeably the C 1s core level. The results indicate that the gap state and energy level positions can be decoupled in the organic semiconductors, and that it is possible to fine tune the electronic structure by selective doping in the interface region.
INFLUENCE OF HETEROATOM DOPING OF TiO2 NANOPARTICLE ON THE RED SHIFT AND THE RELATED CATALYTIC ACTIVITY
Authors: SATHISH M. , VISWANATHAN B. , VISWANATH R. P.
Published: May 2007

N -doped anatase TiO 2 has been prepared by thermal decomposition of Ti containing metal complexes. The light absorption onset has been shifted to the visible region by ~ 100 nm when compared to pure TiO 2. The N environment of N -doped TiO 2 has been studied by XPS and the results confirm the presence of N – Ti – O in the N -doped samples. Also, there is a shift in the binding energy values of Ti 2p3/2, and the additional peak for O 1s in N -doped TiO 2 confirms the increase in the covalent nature of TiO 2 during the N -doping. The photocatalytic activity of N -doped TiO 2 has been studied both in the UV and visible regions and N -doped TiO 2 shows higher activity than the Degussa TiO 2 in the visible region.
INFLUENCE OF OXYFLUORINATION ON TRANSPORT MECHANICAL PROPERTIES OF PAN-BASED CARBON FIBERS
Authors: PARK SOO-JIN , OH JIN-SEOK , RHEE KYONG-YOP
Published: May 2007

In this work, the effect of oxyfluorination on surface characteristics of carbon fibers was investigated in terms of fracture toughness and crack resistance properties of the epoxy matrix composites. The surface properties of the carbon fibers were determined by the acid-base values, X-ray photoelectron spectroscopy (XPS), and FT-IR measurements. And their fracture toughness of the composites was studied in critical stress intensity factor K IC and critical energy release rate mode II G IIC . As the experimental XPS results showed, O 1S / C 1S ratio was increased by oxyfluorination, due to the oxygen-containing functional groups and the format in the C – F x bonds on carbon fiber surfaces. It was found that the fracture toughness and crack resistance of the composites were improved by the oxyfluorination, which could probably be attributed to the increase of the degree of adhesion at the interfaces between the carbon fibers and epoxy resin matrix in the present composite system.
NANOSTRUCTURED DENDRIMER MODIFIED GLASS SURFACES FOR PROTEIN MICROARRAY
Authors: AJIKUMAR PARAYIL KUMARAN , NG JIN KIAT , LEE JIM YANG , STEPHANOPOULOS GREGORY , TOO HENG-PHON
Published: May 2007

Carboxyl PAMAM dendrimer (3.5 generation) was covalently coupled onto amine modified glass surface to prepare a monolayer of high density functional linkers. Activation of the carboxyl PAMAM surface and the subsequent immobilization of antibodies resulted in a high density protein microarray as compared to linear carboxyl linker surface. In addition, fluorescent labeled cell lysate showed extremely low nonspecific adsorption to the PAMAM modified surface, comparable to inert PEG surface. Thus, the carboxyl PAMAM modified surface is ideal for the generation of high density protein arrays for the detection of dilute antigens with superior sensitivity.
VAPOR-PHASE CHEMICAL FUNCTIONALIZATION OF HIGH POROSITY, NANOSTRUCTURED THIN FILMS
Authors: TSOI SHUFEN , FOK ENRICO , VEINOT JONATHAN G. C. , SIT JEREMY C.
Published: May 2007

Trifluoropropyl-trichlorosilane reagents were used to tailor the surface chemistry of porous nano-structured thin films fabricated using glancing angle deposition (GLAD). GLAD produces high surface area films of isolated columnar structures and provides complete control over the film morphology. Here, the chemical tunability of these GLAD films was investigated using solution and vapor-phase surface functionalization methods. All films were characterized using scanning electron microscopy, X-ray photoelectron spectroscopy and advancing aqueous contact angle measurements. Our results indicate that the surface chemistry of the GLAD films was effectively changed after functionalization by either approaches. We also note that vapor-phase functionalization provides more consistent results and eliminates the need for organic solvents, making it an ideal method for tailoring the surface properties of GLAD films for specific applications.
ERROR ESTIMATES ON A BACKWARD HEAT EQUATION BY A WAVELET DUAL LEAST SQUARES METHOD
Authors: XIONG XIANG-TUAN , FU CHU-LI
Published: May 2007

We apply a wavelet dual least squares method to a backward heat equation. Connecting Shannon wavelet bases with a special project method, the dual least squares method, we can obtain a regularized solution. Meanwhile, a new error estimate between the approximate solution and exact solution is proved.
MODELING TANGENTIAL VECTOR FIELDS ON REGULAR SURFACES BY MEANS OF MIE POTENTIALS
Authors: FREEDEN WILLI , MAYER CARSTEN
Published: May 2007

By means of the limit and jump relations of classical potential theory with respect to the vectorial Helmholtz equation, a wavelet approach is established on a regular surface. The multiscale procedure is constructed in such a way that the emerging scalar, vectorial and tensorial potential kernels act as scaling functions. Corresponding wavelets are defined via a canonical refinement equation. A tree algorithm for fast decomposition of a tangential complex-valued vector field given on a regular surface is developed based on numerical integration rules. Some numerical test examples conclude the paper.
TEXTURE CLASSIFICATION USING CURVELET TRANSFORM
Authors: ARIVAZHAGAN S. , SUBASH KUMAR T. G. , GANESAN L.
Published: May 2007

Texture classification has long been an important research topic in image processing. Nowadays classification based on wavelet transform is being very popular. Wavelets are very effective in representing objects with isolated point singularities, but failed to represent line singularities. Recently, ridgelet transform which deal effectively with line singularities in 2D is introduced. But images often contain curves rather than straight lines, so curvelet transform is designed to handle it. It allows representing edges and other singularities along lines in a more efficient way when compared with other transforms. In this paper, the issue of texture classification based on curvelet transform has been analyzed. Features are derived from the sub-bands of the curvelet decomposition and are used for classification for the four different datasets containing 20, 30, 112 and 129 texture images respectively. Experimental results show that this approach allows high degree of success rate in classification to be obtained.
WEIGHTED HAAR WAVELETS ON THE SPHERE
Authors: ROŞCA DANIELA
Published: May 2007

Starting from the one-dimensional Haar wavelets on the interval [0,1], we construct spherical Haar wavelets which are orthogonal with respect to a given scalar product. This scalar product induces a norm which is equivalent to the usual ‖ · ‖2norm of L2(𝕊2). Thus, the Riesz stability in L2(𝕊2) is assured and we can use the algorithms of decomposition and reconstruction from the Haar wavelets in 2D. Another advantage is that we avoid the problems around the poles, which occur in other approaches. As example, we decompose a data set, showing the graphs of the approximations and details and thus the capability to detect the singularities (contours). The method described here can be also used for constructing spherical wavelets starting from wavelets on an interval.
SEMANTIC ANALYSIS OF BIOLOGICAL IMAGING DATA: CHALLENGES AND OPPORTUNITIES
Authors: AHMED WAMIQ MANZOOR , AYYAZ MUHAMMAD NAEEM , RAJWA BARTEK , KHAN FARRUKH , GHAFOOR ARIF , ROBINSON J. PAUL
Published: May 2007

Microscopic imaging is one of the most common techniques for investigating biological systems. In recent years there has been a tremendous growth in the volume of biological imaging data owing to rapid advances in optical instrumentation, high-speed cameras and fluorescent probes. Powerful semantic analysis tools are required to exploit the full potential of the information content of these data. Semantic analysis of multi-modality imaging data, however, poses unique challenges. In this paper we outline the state-of-the-art in this area along with the challenges facing this domain. Information extraction from biological imaging data requires modeling at multiple levels of detail. While some applications require only quantitative analysis at the level of cells and subcellular objects, others require modeling of spatial and temporal changes associated with dynamic biological processes. Modeling of biological data at different levels of detail allows not only quantitative analysis but also the extraction of high-level semantics. Development of powerful image interpretation and semantic analysis tools has the potential to significantly help in understanding biological processes, which in turn will result in improvements in drug development and healthcare.
OVERVIEW AND FUTURE TRENDS OF MULTIMEDIA RESEARCH FOR CONTENT ACCESS AND DISTRIBUTION
Authors: SHYU MEI-LING , CHEN SHU-CHING , SUN QIBIN , YU HEATHER
Published: May 2007

The advances in information technology, computational capability, and communication networks have enabled large-scale data collection and distribution of vast amounts of multimedia data available to consumer and enterprise applications. With the proliferation of multimedia data and ever-growing requests for multimedia applications, reliable and efficient tools and techniques are urgently sought for multimedia content analysis and retrieval, as well as secure media streaming, distribution or communication. Though many research efforts have been devoted to these aspects, it is still far from maturity and there exist many open issues. In this paper, an overview of the challenges and issues as well as future trends on multimedia content access and distribution will be discussed. The focuses include: (i) how to bridge the gaps between the semantic meaning and low-level media characteristics; (ii) how to handle user perception subjectivity problem; (iii) how to provide multimedia network communication support for media streaming and P2P (peer-to-peer) media distribution; and (iv) how to ensure various aspects of secure media, including acquisition, processing, storage, and communication.
Evaluation of GERD Symptoms during Therapy
Authors: Mönnikes H. , Bardhan K.D. , Stanghellini V. , Berghöfer P. , Bethke T.D. , Armstrong D.
Published: May 2007

Background/Aims:Evaluation of the response of gastroesophageal reflux disease (GERD) symptoms to treatment would be facilitated by a brief, valid, reliable and responsive, self-assessed GERD-sensitive scale. We therefore developed the Reflux Questionnaire (ReQuest™). This publication describes the psychometric evaluation and validation of ReQuest™. Methods:This second phase of development was based on data from a clinical trial of patients with erosive GERD who received pantoprazole 20 or 40 mg daily for 28 days and completed weekly the long, and daily the short version of ReQuest™. The psychometric analyses of ReQuest™ included internal consistency, test-retest reliability and responsiveness. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) scale. Results:Validation of ReQuest™ indicated very high internal consistency (Cronbach’s α = 0.90) and test-retest reliability (intraclass correlation coefficient 0.94 (long-long) and 0.86 (short-short)). This was also the case for the two subscales ReQuest™-GI and ReQuest™-WSO with Cronbach’s α coefficients of 0.84 and 0.81. Responsiveness was high with a responsiveness index of >0.8 at day 28. Construct validity was good. Conclusion:ReQuest™ is a highly reliable, valid and responsive self-assessment tool for evaluating treatment response in patients with erosive GERD, and can be applied daily.
ReQuest™: A New Questionnaire for the Simultaneous Evaluation of Symptoms and Well-Being in Patients with Gastro-Oesophageal Reflux
Authors: Ducrotté Philippe , Zerbib Frank
Published: May 2007

ReQuest™ is a self-reported questionnaire developed to assess, during clinical trials investigating GERD with or without oesophagitis, not only heartburn and acid regurgitation, but the broad spectrum of GERD symptoms. ReQuest™ comprises 2 sub-scales: ReQuest™-GI which covers the 4 dimensions related to gastrointestinal symptoms (acid complaints, upper abdominal/stomach complaints, lower abdominal/digestive complaints, and nausea) and ReQuest™-WSO which analyses the three other dimensions (general well-being, sleep disturbances, and other complaints). This self-reported questionnaire, which is completed daily, is available in two forms: a short version quantifying the intensity (10-cm VAS) and frequency (7-point Likert scale) of each of the six main dimensions of the scale and the intensity only of the general well-being dimension, and a longer version which includes, in addition to a global evaluation, a detailed analysis of all the symptoms contributing to each dimension. ReQuest™ is a tool with proven metrological strengths, enabling the investigators to follow – on a daily, multidimensional and reliable basis – the evolution of GERD in the course of clinical trials. Both versions, the long and the short, have identical metrological qualities.
Motion Artifact Reducing Reconstruction of 4D CT Image Data for the Analysis of Respiratory Dynamics
Authors: Ehrhardt J. , Frenzel T. , Säring D. , Lu W. , Low D. , Handels H. , Werner R.
Published: May 2007

Objectives:
Respiratory motion represents a major problem in radiotherapy of thoracic and abdominal tumors. Methods for compensation require comprehensive knowledge of underlying dynamics. Therefore, 4D (= 3D + t) CT data can be helpful. But modern CT scanners cannot scan a large region of interest simultaneously. So patients have to be scanned in segments. Commonly used approaches for reconstructing the data segments into 4D CT images cause motion artifacts. In orderto reduce the artifacts, a new method for 4D CT reconstruction is presented. The resulting data sets are used to analyze respiratory motion.

Methods:
Spatiotemporal CT image sequences of lung cancer patients were acquired using a multi-slice CT in cine mode during free breathing. 4D CT reconstruction was done by optical flow based temporal interpolation. The resulting 4D image data were compared with data generated bythe commonly used nearest neighbor reconstruction. Subsequent motion analysis is mainly concerned with tumor mobility.

Results:
The presented optical flow-based method enables the reconstruction of 3D CT images at arbitrarily chosen points of the patient’s breathing cycle. A considerable reduction of motion artifacts has been proven in eight patient data sets. Motion analysis showed that tumor mobility differs strongly between the patients.

Conclusions:
Due to the proved reduction of motion artifacts, the optical flow-based 4D CT reconstruction offers the possibility of high-quality motion analysis. Because the method is based on an interpolation scheme, it additionally has the potential to enable the reconstruction of 4D CT data from a lesser number of scans.
Statistical Image Reconstruction for Inconsistent CT Projection Data
Authors: Oehler M. , Buzug T. M.
Published: May 2007

Objectives:
The filtered backprojection is not able to cope with metal-induced inconsistencies in the Radon space which leads to artifacts in reconstructed CT images. A new algorithm is presented that reduces the drawbacks of existing artifact reduction strategies.

Methods:
Inconsistent projection data are bridged by directed interpolation. These projections are reconstructed using a weighted maximum likelihood algorithm (λ-MLEM). The correlation coefficient between images of a torso phantom marked with steel markers reconstructed with λ-MLEM and images of the same torso slice without markers quantifies the quality achieved. For clinical data, entropy maximization is presented to obtain appropriate weightings.

Results:
Different interpolation strategies have been applied. The quality of reconstruction sensitively depends on the complexity of interpolation. A directional interpolation gives best results. However, the quality of the images can be further improved byan appropriate weighing within λ-MLEM. This has been demonstrated with data from a torso phantom, a jaw with amalgam fillings and a hip prosthesis.

Conclusions:
λ-MLEM image reconstruction using data from directional Radon space interpolation is a new approach for metal artifact reduction. The weighting in this statistical approach is used to reduce the influence of residual inconsistencies in a way that optimal artifact suppression is obtained by optimizing a compromise between residual inconsistencies and void data. The image quality is superior compared with other artifact reduction strategies.
Interactive Diffusion-based Smoothing and Segmentation of Volumetric Datasets on Graphics Hardware
Authors: Langer C. , Fritz L. , Hadwiger M. , Wolfsberger S. , Bühler K. , Beyer J.
Published: May 2007

Objective
: Volume segmentation with concurrent visualization is becoming an increasingly important part of medical diagnostics. This is due to the fact that the immediate visual feedback speeds up evaluation of the segmentation process, hence enhances segmentation quality. Therefore, our aim was to develop a method for volume segmentation and smoothing which achieves interactive performance on standard PCs and is useful in clinical practice (i.e. fast and of high quality).

Methods
: Our application is based on seeded region growing and nonlinear isotropic as well as anisotropic diffusion. We use current GPUs (graphics processing units) to speed up the computation of the diffusion process and use hardware-accelerated interactive volume rendering.

Results
: Using our approach the user can observe the diffusion process in real-time, change parameters interactively and view the result in a high-quality 3D direct volume rendering (DVR).

Conclusion
: The interactive nature of our algorithm and simultaneous visualization improved the usability of our segmentation and smoothing algorithm and proved useful in the clinical workflow. Using our application we were able to speed up the (an)isotropic diffusion process to achieve interactive performance.
Interactive Virtual Hair Salon
Authors: Ward Kelly , Galoppo Nico , Lin Ming
Published: May 2007

User interaction with animated hair is desirable for various applications but difficult because it requires real-time animation and rendering of hair. Hair modeling, in cluding styling, simulation, and rendering, is computationally challenging due to the enormous number of deformable hair strands on a human head, elevating the computational complexity of many essential steps, such as collision detection and self-shadowing for hair. Using simulation localization techniques, multi-resolution representations, and graphics hardware rendering acceleration, we have developed a physically-based virtual hair salon system that simulates and renders hair at accelerated rates, enabling users to interactively style virtual hair. With a 3D haptic interface, users can directly manipulate and position hair strands, as well as employ real-world styling applications (cutting, blow-drying, etc.) to create hairstyles more intuitively than previous techniques.