bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF WATER ON DUCTILITY AND FATIGUE STRENGTH OF AUSTEMPERED DUCTILE CAST IRON (ADI)
Authors: YAKUSHIJI TERUTOSHI , FERGUSON W. GEORGE , GOTO MASAHIRO
Published: November 2006

In order to study the mechanism of decreasing tensile strength and elongation of Austempered Ductile Cast Iron (ADI) in the wet condition, various tension tests and impact tests were carried out. Three point bending fatigue tests were carried out on ADI and annealed 0.55% carbon steel to clarify the influence of water on fatigue strength. The main conclusions are as follow. Embrittlement by water begins when plastic deformation starts in a tension test. The fatigue limit of ADI in water showed a lower value than that in air. The influence of a water environment on fatigue behaviour was similar to that of annealed 0.55% carbon steel. Embrittlement such as that in a tension test was not observed in a fatigue test.
THE STRUCTURAL DEVELOPMENT OF NYLON6/LAYERED SILICATE NANOCOMPOSITE DURING ZONE-DRAWING
Authors: HAN SUNG SOO , CHO YANG-WHAN , PARK SOO-YOUNG
Published: November 2006

The structural development of nylon6/layered silicate nanocomposite during zone-drawing was studied using X-ray scattering and dynamic mechanical thermal analysis. The γ form, which was favored in the pressed film, was converted into the α form during zone-drawing. The newly developed α form, during zone-drawing, has a better orientation than the existing γ form, thus supporting the claim that the α form crystallizes away from the polymer-silicate inter-phase region during drawing. The degree of orientation of the layered silicate, projected along the TD direction, increases with the increase of the draw ratio, suggesting that the layered silicate has become straighter during zone-drawing, although the layered silicate within the zone-drawn film buckled perpendicular to the draw direction. The β transition of the dynamic mechanical thermal analysis is independent of the crystalline phase, although the α transition is strongly dependent upon the crystalline phase. This can be explained by the free volume that exists in the inter-phase between the γ lamellar and the layered silicate.
EFFECT OF WEIGHT LOSS AND MICROSTRUCTURE BY HEAT TREATMENT AND FABRICATION OF LPS-SIC CERAMICS
Authors: YOON HAN-KI , PARK JOON SOO , KOHYAMA AKIRA
Published: November 2006

In the present work, monolithic LPS- SiC was fabricated by hot press method with the addition of Al 2 O 3, Y 2 O 3 and SiO 2 and annealed at different temperatures to observe microstructure evolution. Process temperature was varied from 1760°C to 1800°C. Process pressure and maturing time are 20MPa and 1h respectively. Hot pressed samples were cut into rectangular bars. Three-point flexural strength was measured at room temperature in air with a cross-head speed of 0.1 mm/min and a lower span of 18 mm. Flexural strength and elastic modulus measurement was performed using a universal test machine (INSTRON 5581, USA). The apparent density of the sintered body was measured by the Archimedes method. The specimen dimension of the heat treatments is 4 W ×25 L ×1.5 T mm . The specimens used for weight-loss measurement were set into an open carbon crucible to avoid nonuniform temperature distribution within the furnace. Post-fabrication heat treatment was performed in vacuum atmosphere ( PO 2 ≈ 0.01 Pa ). The temperature was increased at a rate of 20 K/min to the heat-treatment temperature and maintained for 10 hours, after which the specimens were furnace cooled. After heat-treatment, weight of heat-treated specimens was carefully measured by an electronic balance. In order to reveal the microstructural change in heat-treated specimen, X-ray diffractometry and microstructure observation were performed and compared with those of the as-fabricated one.
PREPARATION OF 1,1-DIARYLETHENES BY MCMURRY REACTION: MECHANISM AND GEOMETRY SELECTION
Authors: ISHIDUKA TAKAAKI , TSUKAYAMA MASAO , KAWAMURA YASUHIKO
Published: November 2006

The McMurry crossed coupling reactions of p,p′-disubstituted benzophenones (1) with pivalaldehyde (Pv) gave the corresponding ethenes (2) in fair to excellent yield. The observed geometrical selectivity is varied depending on a kind of p-substituent of the aromatic moiety of 1, when p′-substituent is limited to methyl. According to the known reaction mechanism, the reason why the geometry selection occurred is discussed by a conformational analysis of a possible intermediate, titanium bound pinacolate, and molecular orbital calculations of the starting carbonyl compounds. As a result, the selection is caused by electronic and stereochemical structures of anion radical of 1 and approaching mode of Pv anion radical to them. Distribution of a spin density and unsymmetrical nature of two aromatic moieties of anion radical of 1 provide predetermined pathway to bring about the pinacolate without any rotational conversion under the reaction conditions. Subsequent workup affords 2 with the observed geometry.
MANUFACTURING FLAX FIBRE-REINFORCED POLYPROPYLENE COMPOSITES BY HOT-PRESSING
Authors: JOLLY MARC , JAYARAMAN KRISHNAN
Published: November 2006

The renewable characteristic of natural fibres, such as flax, and the recyclable nature of thermoplastic polymers, such as polypropylene, provide an attractive eco-friendly quality to the resulting composite materials. Common methods for manufacturing natural fibre-reinforced thermoplastic composites, injection moulding and extrusion, tend to degrade the fibres during processing. Development of a simple manufacturing technique for these composites, that minimises fibre degradation, is the main objective of this study. Flax fibres were conditioned, cut into lengths ranging from 1 mm to 30 mm with scissors and a pelletiser, and shaped into randomly oriented mats using a drop feed tower. Polypropylene in sheet form, was added to the fibres to furnish polypropylene/flax/polypropylene sandwiches with a fibre mass fraction of 25%, which were then consolidated by the hot pressing technique. Tensile, flexural and impact properties of these composite sheets were determined as functions of fibre length and processing temperature.
EFFECTS OF EXTRUSION ON FIBRE LENGTH IN SISAL FIBRE-REINFORCED POLYPROPYLENE COMPOSITES
Authors: PATHI SRIDHAR , JAYARAMAN KRISHNAN
Published: November 2006

Natural fibre reinforced thermoplastic composites find a wide array of applications in the automobile, building and construction industries. These composites are mostly produced by injection moulding or extrusion through properly designed dies. During these production processes, the shear forces exerted by the screw or ram leads to the degradation of the natural fibres. A screwless extruder that minimises fibre degradation and employs a reliable and low technology process has already been developed. However, the fibre degradation caused by the screwless extruder has not been compared with that of the conventional extruders. So, this study is focused on the influence of extrusion processes on the degradation of natural fibres in thermoplastic composites. Sisal fibres of 10 mm length were extruded with polypropylene, to furnish extrudates with a fibre mass fraction of 25%, using conventional single screw and screwless extruders. Polypropylene in the extrudates was dissolved in Xylene in a Sohxlet process; the fibres that were extracted were analysed for length variations. While fibre degradation in the form of fibre length variation is similar in both cases, this can be minimised in screwless extrusion by extending the gap between the front face of the cone and the orifice plate.
THE DETECTION PROBABILITY IMPROVEMENT OF THE FAR-SIDE CRACK ON THE HIGH LIFT-OFF USING THE MAGNETIC CAMERA
Authors: LEE JINYI , HWANG JISEONG
Published: November 2006

To evaluate cracks using magnetic flux leakage (MFL), the distribution of magnetic field (DMF) near the crack should be quantified. A narrow spatial resolution of DMF is demanded around the crack. Also the lift-off should increase over several mm to protect the sensors from environments such as high temperature, dust, and vibration. Furthermore, the MFL must be amplified to detect a far-side crack because the MFL will concentrate in the ferromagnetic specimen and will be weak. The magnetic camera and magnetic lens could be useful for high lift-off conditions such as in nondestructive testing of a far-side environment. The far-side crack detection probabilities, Max(∂B/∂x) and RMS(∂B/∂x), were improved by about 20~60% by using the magnetic lens. The crack can be easily detected by using the 1/4RMS algorithm. Finally, an equation that expresses the relationship between the volume of crack and Max(∂B/∂x) is proposed. This equation is based on the principle that the magnetic field is inversely proportional to the square of the lift-off and is useful for determining the crack volume when the lift-off is known.
CHARACTERIZATION OF ZnO FILMS BY ION BEAM ANALYSIS
Authors: KENNEDY JOHN , MARKWITZ ANDREAS , LI ZHENGWEI , GAO WEI
Published: November 2006

Ion Beam Analysis (IBA) techniques such as Rutherford Backscattering Spectrometry (RBS) and Elastic Recoil Detection Analysis (ERDA) were used to determine the composition, uniformity, impurity and elemental depth profiles of Zn , O and H in ZnO films deposited on silicon, quartz, glass and glassy carbon using radio frequency (RF) magnetron sputtering. For the films deposited under the same condition, it was observed that the variation of Zn/O ratios is independent of substrate material and depends on the film thickness. ERDA revealed that the hydrogen impurities were incorporated into the films. Higher hydrogen concentrations were found for the films deposited on glass and quartz compared to Si . The composition and thickness variation in relationship with three different substrates were explored with XRD, SEM, AFM, PL and Hall probe measurements. It was found that ZnO films (250-300 nm) deposited on Si have, the optical and electrical properties which make them suitable candidate for following p-type doping studies using ion implantation and annealing techniques.
OPTICAL CHARACTERISTICS OF PHOSPHORESCENT MATERIALS WITH WATER-BASED CERAMICS
Authors: FUJITA AKIHIRO , KAGAMI SHINYA , JONES MARK I.
Published: November 2006

A composite coating approach has been employed to produce phosphorescent materials for emergency exit signs. The coating consists of a reflecting undercoat, a middle coating comprising phosphorescent pigments in a water based ceramic, and a final transparent silica topcoat. The effects of size and amount of pigments in the ceramic based coating on the luminance of the materials was assessed and compared with the Japanese Industrial Standard for safety signboards (JIS Z9107). The luminance increased with the amount of pigment in the coating, and samples with more than 20% exceeded the standard. Luminance 10 times higher than the JIS standard was obtained with 50% phosphorescent pigments. The luminance increased initially with the number of applications of the ceramic based coating but there was no further increase for more than 4 applications. The water-based phosphorescent ceramics developed here are superior in optical characteristics and made entirely of inorganic materials. It is considered that these are excellent materials for phosphorescent emergency exit signs. In addition, the materials can be applied at room temperature for example to metal substrates or by silkscreen printing on tiles, and then calcined at low temperature. This type of processing makes them suitable for a whole range of applications.
HYDROTHERMAL SYNTHESIS AND DIELECTRIC PROPERTIES OF LEAD TITANATE CERAMIC
Authors: DENG YUAN , CUI CHANG-WEI , YE HUI-HONG
Published: November 2006

Lead titanate ( PbTiO 3) powders were synthesized via a hydrothermal method based on the reaction of TiO 2, Pb ( NO 3)3 and KOH at 160°C for 24h. The powders were characterized by XRD, SEM and TEM. The PbTiO 3 particles consist of nearly homogenous and cubic grains. It can be sintered to ceramic above 1050°C, and the samples show higher dielectric constant value.
EFFECT OF MILLING PARAMETERS ON MICROSTRUCTURE OF Ti/Al COMPOSITE POWDER PRODUCED BY DISCUS MILLING
Authors: RAYNOVA S. , CAO P. , GABBITAS B. , ZHANG D.
Published: November 2006

The motivation of this research is to develop a process for producing Ti/Al composite powders that enable synthesis of a single-phase TiAl intermetallic bulk material, which is then used as a target for physical vapour deposition (PVD) coating. This study reports the effects of milling time, amount of process control agent (PCA) added as well as the powder-to-medium ratio on the microstructure of the Ti/Al composite powder. Optical microscopy and scanning electron microscopy (SEM) were used to evaluate the level of mixing and the resulting powder particle size. X-ray diffraction analysis and differential thermal analysis were used for determining the phase constituents and the solid state reaction temperature of the as-milled powders.
THERMAL STRESS BEHAVIOR IN NANO-SIZE THIN ALUMINUM FILMS
Authors: HANABUSA TAKAO , KUSAKA KAZUYA , SHINGUBARA SHOSO , SAKATA OSAMI
Published: November 2006

In-situ observation of thermal stresses in thin films deposited on a silicon substrate was made by synchrotron radiation. Specimens prepared in this experiment were nano-size thin aluminum films with SiO 2 passivation. The thickness of the films was 10 nm, 20 nm and 50 nm. Synchrotron radiation revealed the diffraction intensities for these thin films and make possible to measure stresses in nano-size thin films. Residual stresses in the as-deposited state were tensile. Compressive stresses were developed in a heating cycle up to 300°C and tensile stresses were developed in a cooling cycle. The thermal stresses in the 50 nm film showed linear behavior in the first heating stage from room temperature to 250°C followed by no change in the stress at 300°C, however, linearly behaved in the second cycle. On the other hand, the thermal stresses in 20 nm and 10 nm films almost linearly behaved without any hysteresis in increasing and decreasing temperature cycles. The mechanism of thermal stress behavior in thin films can be explained by strengthening of the nano-size thin films due to inhibition of dislocation source and dislocation motion.
MICROSCOPIC PROPERTIES OF BONE TISSUE USING MEASUREMENT SYSTEM WITH NANO-RESOLUTION
Authors: HONG JUNGHWA , PARK YOUNG-WHAN , CHA HEE-SUNG , KHANG GON
Published: November 2006

To understand the physiology and pathology of human skeletal system, the accurate measurement of microscopic biomechanical properties of bone is an important works. In this study, a measurement system of the Poisson's ratio with a sub-nano resolution was developed. The resulting resolution of the system was 0.3 nm, which was 0.1% of the measurement error for this system configuration. Using this measurement system, actual tests were performed to check the capability of the measurement system. Cubic bone specimens with a dimension of 300 μm were loaded up to an axial strain of 0.5%, which is within the elastic range of the specimens. The mean elastic modulus and the Poisson's ratio of bovine femoral cortical bone measured in this study were 14.42 GPa ( SD ± 0.6179) and 0.265 ( SD ± 0.0125) respectively. The developed system will be useful to understand the biomechanics of bones for modeling the mechanobiological bone system.
DRY SLIDING WEAR BEHAVIOUR OF FLYASH REINFORCED ZA-27 ALLOY BASED METAL MATRIX COMPOSITES
Authors: SHARMA S. C. , KRISHNA M. , BHATTACHARYYA D.
Published: November 2006

In the present investigation, an attempt has been made to evaluate the wear rate of ZA-27 alloy composites reinforced with fly ash particles from 1 to 3 wt% in steps of 1 wt%. The compo-casting method has been used to fabricate the composites using Raichur fly ash of average size 3-5 microns. The wear specimens are tested under dry conditions using a pin-on-disc sliding wear testing machine with wear loads of 20-120 N in steps of 20 N, and the sliding distances in the range of 0.5 km to 2.5 km. The results indicate that the wear rate of the composites is less than that of the matrix alloy and it further decreases with the increase in fly ash content. However, the material loss in terms of wear rate and wear volume increases with the increase in load and sliding distance, both in the cases of composites and the matrix alloy. An increase in the applied load increases the wear severity by changing the wear mechanism from abrasion to particle-cracking induced delamination wear. It is found that with the increase in fly ash content, the wear resistance increases monotonically. The observations have been explained using scanning electron microscope (SEM) analysis of the worn surfaces of the composites.
ANALYSIS OF EFFECT OF GAS–LIQUID INTERFACIAL DISTURBANCE ON MASS TRANSFER PERFORMANCE
Authors: WU HONDA , CHUNG TSAIR-WANG
Published: November 2006

In order to study the mass transfer phenomena for water vapor absorbed by triethylene glycol (TEG) solution and to elucidate effect of interfacial disturbance on absorption performance, the interfacial phenomena for water drop instilling on the surface of TEG solution and mass transfer process were observed and operated in this study. Besides liquid and gas flow rates, the interfacial disturbance can also affect the mass transfer performance in the absorption system with continuous liquid phase, and the advanced mass transfer phenomena must be discussed from the interface of matter. Therefore, the surface tensions of desiccant solutions were measured to analyze the disturbed phenomena of water drop instilling on the surface of TEG solution. Since the Marangoni-Index (MI) means the maximum surface tension difference on the surface of liquid layer, the values of MI were calculated and compared with the mass transfer performance of packed-bed absorber. Generally speaking, the interfacial disturbance, resulted from the surface tension difference, would promote the contacting area of gas and liquid phases. The observation of water drop instilling on surface of TEG solution found that the interfacial disturbance existed between water drop and TEG solution, and the interfacial instability was found in the peripheral region of the water drop. On the other hand, the values of MI were increased by the increased TEG concentrations, and it can be deduced that the surface tension effect should be significant in the higher concentration of TEG solution and the interfacial disturbance would be heavier above 95 wt.% TEG solutions. Finally, the absorption performance for 95 and 96 wt.% TEG solutions were much larger than that of 90 and 88.6 wt.% TEG solutions in the operation of packed-bed absorber.
ADHESION OF PET/PSMA INTERFACES REINFORCED WITH PLASMA TREATMENT
Authors: DAI CHI-AN , TSUI TAI-AN , CHENG YAO-YI
Published: November 2006

The interface between biaxially oriented poly (ethylene terephthalate) (PET) films and poly (styrene-co-maleic anhydride) (PSMA) was reinforced by nitrogen plasma treatment of PET film and subsequent annealing treatment of the PET/PSMA bi-material. The fracture toughness, Gc, of the interface was quantitatively measured using an asymmetric double cantilever beam test (ADCB). X-ray photoelectron spectrometry (XPS) was used to measure the change in the surface composition of PET films upon plasma treatment and correlate the fracture toughness of the interface. The fracture energy of PET/PSMA interface is significantly enhanced by annealing the plasma treated PET with PSMA at a temperature greater than the glass transition temperature of PSMA (~ 120°C). At an annealing temperature of 150°C, Gc increases with increasing plasma treatment time and reaches a plateau value of ~ 100–120 J/m2, a two order of magnitude increase in Gc compared with that of samples annealed at 130°C. The enhancement of the adhesion is resulted from the in-situ formation of copolymers due to reaction between amine functional groups from the plasma treatment and anhydride groups from PSMA. For plasma treatment time < 10 s, scanning electron microscope (SEM) measurement show that the fracture surface is relatively smooth indicating an interfacial failure between PET/PSMA. With increasing plasma treatment time and therefore increasing the amount of nitrogen functional groups on PET surface, large plastic deformation takes place at the PET/PSMA interface. For treatment time ≥ 100–150 s, the PET/PSMA interface becomes stronger than PET bulk material and consequently crack deviates from the interface and the failure occurs within the PET film. The interlayer fracture energy of a biaxially oriented PET film can thus be quantitatively measured with a Gc value of roughly 120 J/m2.
SURFACE PHOTODEGRADATION OF POLY(VINYLIDENE FLUORIDE) BY INNER-SHELL EXCITATION
Authors: OKUDAIRA KOJI KAMIYA , KOBAYASHI EIICHI , MASE KAZUHIKO , KERA SATOSHI , UENO NOBUO
Published: November 2006

Poly(vinylidene fluoride) (PVDF, –( CH 2– CF 2)n–) shows the effective H + desorption induced by the irradiation of photon corresponding to the transition from carbon ( C ) 1s to σ( C – H )*. In order to clarify the effect of the C – H bond scission by the irradiation, near-edge X-ray absorption fine structure (NEXAFS) spectra and the kinetic energy (Ek) distribution of desorbed ion were observed. By the irradiation of photon near C 1s region, a new peak appears in the C 1s NEXAFS spectra at photon energy of 285 eV, which is about 3 eV lower than that of the lowest peak in the NEXAFS spectrum of the pristine PVDF film. The appearance of the lowest NEXAFS peak of irradiated PVDF film is assigned to the transition to π*. It indicates that the irradiation of photons near C 1s region introduces carbon–carbon double bonds into the backbone chain of PVDF. At early stage of X-ray exposure the yield of desorbed ion with low Ek (~ 2 eV) decreases rapidly. The ion with low Ek is assigned to H + desorbed from the sp3-hybrid state, which is characteristics of the pristine PVDF. It indicates that formation of double bonds in PVDF backbone chain makes the number of sp3-hybrid state decrease. This variation occurs by irradiation of photons corresponding to the transition from C 1s to σ( C – H )* more rapidly than that to the transition to σ( C – F )*.
AMPHIPHILIC COMB-SHAPED DIBLOCK POLYMER BRUSHES ONSi(100) SUBSTRATES VIA SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION
Authors: PENG JIN-WEN , HUANG WEI , KANG EN-TANG , NEOH KOON GEE
Published: November 2006

Amphiphilic comb-shaped 2-hydroxyethyl methacrylate-graft-poly(styrene)-block-poly(poly (ethylene glycol) monomethacrylate) ( P ( HEMA )–g– PS –b– P ( PEGMA )) copolymer brushes, covalently tethered on Si (100) substrate, have been successfully prepared by (i) UV-induced hydrosilylation of 4-vinylbenzyl chloride (VBC) with the hydrogen-terminated Si (100) ( Si – VBC surface), (ii) surface-initiated atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate (HEMA) to give the Si – VBC –g– P ( HEMA ) surface, (iii) coupling of 2-bromoisobutyryl bromide with the HEMA units via esterification to provide the comb-shaped macroinitiators ( Si – VBC –g– P ( HEMA )– R3Br ) for the subsequent ATRP, (iv) surface-initiated ATRP of styrene (St) to produce the Si – VBC –g– P ( HEMA )–g– PS surface, and (v) the persisting of an active PS chain end can be used as the initiator for the subsequent ATRP of poly(ethylene glycol) monomethacrylate (PEGMA) to give the amphiphilic Si – VBC –g– P ( HEMA )–g– PS –b– P ( PEGMA ) brush surface. The chemical composition and functionality of the silicon surface were tailored by the well-defined comb-shaped PS and P (PEGMA) brushes.
GROWTH MODE AND ELECTRONIC STRUCTURE OF SILVER ON ${\rm ZnO}(10\overline{1}0)$
Authors: OZAWA K. , SATO T. , KATO M. , EDAMOTO K.
Published: November 2006

The growth mode and electronic structure of the vapor-deposited Ag overlayer on the [Formula: see text] surface is investigated by angle-resolved photoemission spectroscopy utilizing synchrotron radiation. The coverage dependent measurements of the two-dimensional band structure by the Ag 4d states reveal that the bands with a dispersing feature are developed from the low coverage region, suggesting that the Ag adatoms aggregate to form clusters with a laterally ordered structure. The Ag clusters grow in size with increasing the Ag coverage whereas the ordered atomic structure of the Ag cluster is preserved. From the analysis of the Ag 5sp band, the Ag clusters have a nonmetallic electronic structure at low coverages, and the metallic nature is developed as the size of the clusters becomes enlarged.
ATOMIC STRUCTURE ANALYSIS OF ULTRA THIN IRON SILICIDE FILMS BY STEREO ATOMSCOPE
Authors: KATAOKA K. , MATSUI F. , KATO Y. , GUO F. Z. , MATSUSHITA T. , HATTORI K. , DAIMON H.
Published: November 2006

Three-dimensional atomic arrangements of ultra thin Fe silicide films were directly revealed. By using circularly polarized light with opposite helicities, forward focusing peaks with their positions shifted in photoelectron angular distribution (PEAD) patterns can be obtained. We successfully observed the PEAD patterns of ultra thin Fe silicide films from different core levels of Fe and Si atoms by display-type spherical mirror analyzer (DIANA). The element selective stereo photographs indicate similar hexagonal atomic arrangement with three-fold symmetry for Si and Fe atoms, which is consistent with a model based on a CsCl -type structure with B-type stacking. This is the first observation of stereoscopic atomic arrangements for ultra thin compound films, which implies that the stereo atomscope is very powerful structure analysis tool also for complex structures on surface.
MOLECULAR-SCALE ORGANIC ELECTROLUMINESCENCE FROM TUNNEL JUNCTIONS
Authors: DONG Z. C. , GUO X. L. , WAKAYAMA Y. , HOU J. G.
Published: November 2006

We report the generation and detection of bipolar organic electroluminescence of porphyrin molecules from a nanoscale junction in an ultrahigh vacuum scanning tunneling microscope (STM). Clear molecular fluorescence from porphyrin molecules near metal substrates has been realized through highly localized electrical excitation of molecules in proximity to a sharp tip apex. The molecular origin of the luminescence, arising from the highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) radiative transitions of neutral molecules, is clearly established by the observed well-defined vibrationally resolved fluorescence spectra that match perfectly with conventional photoluminescence data from molecular thin films. The molecules fluoresce at low onset voltages for both bias polarities, presenting an example of bipolar organic electroluminescence at the nanoscale. Such bipolar operation suggests a double-barrier model for electron transport, with hot electron injection into unoccupied states of molecules in both polarities. The optical behavior of molecules in the tunnel junction is also found sensitive to the electronic properties of molecules and energy level alignment at the interface. These results offer new information to the optoelectronic behavior of molecules in a nanoscopic environment and may open up new routes to the development of single-molecule science and molecular scale electronics.
CO-DOPED POLYPYRROLE COATINGS FOR STAINLESS STEEL PROTECTION
Authors: PRISSANAROON W. , BRACK N. , PIGRAM P. J. , LIESEGANG J.
Published: November 2006

Polypyrrole (PPy) films have been successfully electrodeposited on stainless steel substrates in aqueous solution. In this work, three systems of electrolytes were studied: oxalic acid, dodecylbenzenesulfonic acid (DBSA) and a mixture of oxalic acid and DBSA. A combination of XPS and TOF–SIMS revealed the formation of an iron oxalate layer at the interface between the oxalic acid-doped PPy (PPy(Ox)) and stainless steel and a thin layer of DBSA was observed at the interface between DBSA-doped PPy (PPy(DBSA)) and stainless steel. Similar to the PPy(Ox) system, an iron oxalate was also present at the co-doped PPy/stainless steel interface. Cyclic voltammetry indicated that an iron oxalate layer initially formed at the surface of the stainless steel when the co-doping system was used. The adhesion strength and corrosion performance of the PPy coating on stainless steel were evaluated by lap shear tests and an anodic potentiodynamic polarization technique, respectively. The co-doped PPy-coated stainless steel exhibited the best adhesion and a significant shift of corrosion potential to the positive direction. This finding opens the possibility for the co-doped PPy coating to be deployed as a strongly adherent corrosion inhibitor by using a simple one-step electropolymerization process.
NONLINEAR BEHAVIOR OF QUANTUM TRANSPORT THROUGH NANOCONTACTS — AB INITIO CALCULATION STUDY
Authors: HIROSE KENJI , KOBAYASHI NOBUHIKO
Published: November 2006

We study the electronic states and current–voltage (I–V) characteristics of junction systems with atomic-scale nanocontacts as a function of the distance between electrodes by using the first-principles recursion-transfer-matrix (RTM) method combined with nonequilibrium Green function (NEGF) method. We observe a strong nonlinear behavior in the I–V characteristics and correspondingly a gap structure emerges in the differential conductance. We find that such a nonlinear behavior appears when the transport properties change from tunneling to ballistic regimes.
BLOW-UP ANALYSIS FOR SOLUTIONS OF THE LAPLACIAN EQUATION WITH EXPONENTIAL NEUMANN BOUNDARY CONDITION IN DIMENSION TWO
Authors: GUO YU-XIA , LIU JIA-QUAN
Published: November 2006

We consider the asymptotic behavior of solutions of the Laplacian equation with exponential Neumann boundary condition in dimension two. As an application, we prove an existence theorem of nonminimum solutions.
ON THE FUNCTORIALITY OF THE CHERN–SIMONS LINE BUNDLE AND THE DETERMINANT LINE BUNDLE
Authors: FUJITA HAJIME
Published: November 2006

We investigate functorial properties of two hermitian line bundles over the moduli space of flat SU(n)-connections on a closed oriented surface; that is, of the Chern–Simons line bundle and the determinant line bundle. We investigate actions of cyclic subgroups of the mapping class group on them. As a consequence, we show that if we modify the determinant line bundle by the Hodge bundle over the moduli space of Riemann surfaces, then these line bundles are functorially isomorphic. This implies two quantum Hilbert spaces defined by the Chern–Simons line bundle and the modified determinant line bundle are functorially isomorphic.
Educating African American Men about the Prostate Cancer Screening Dilemma: A Randomized Intervention
Authors: Taylor Kathryn L. , Davis Jackson L. , Turner Ralph O. , Johnson Lenora , Schwartz Marc D. , Kerner Jon F. , Leak Chikarlo
Published: November 2006

Background: Until there is a definitive demonstration that early diagnosis and treatment of prostate cancer reduces disease-related mortality, it is imperative to promote informed screening decisions by providing balanced information about the potential benefits and risks of prostate cancer screening. Within a community/academic collaboration, we conducted a randomized trial of a printed booklet and a videotape that were designed for African American (AA) men. The purpose of the trial was to determine the effect of the interventions on knowledge, decisional conflict, satisfaction with the screening decision, and self-reported screening.

Methods: Participants were 238 AA men, ages 40 to 70 years, who were members of the Prince Hall Masons in Washington, DC. Men were randomly assigned to the (a) video-based information study arm, (b) print-based information study arm, or (c) wait list control study arm. Intervention materials were mailed to men at home. Assessments were conducted at baseline, 1 month, and 12 months postintervention. Multivariate analyses, including ANCOVA and logistic regression, were used to analyze group differences.

Results: The booklet and video resulted in a significant improvement in knowledge and a reduction in decisional conflict about prostate cancer screening, relative to the wait list control. Satisfaction with the screening decision was not affected by the interventions. Self-reported screening rates increased between the baseline and the 1-year assessment, although screening was not differentially associated with either of the interventions. In exploratory analyses, prostate-specific antigen testing at 1 year was more likely among previously screened men and was associated with having low baseline decisional conflict.

Conclusions: This study represents one of the first randomized intervention trials specifically designed to address AA men's informed decision making about prostate cancer screening. We have developed and evaluated culturally sensitive, balanced, and disseminable materials that improved knowledge and reduced decisional conflict about prostate cancer screening among AA men. Due to the high incidence and mortality rates among AA men, there is a need for targeted educational materials, particularly materials that are balanced in terms of the benefits and risks of screening. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2179–88)
Family History, Perceived Risk, and Prostate Cancer Screening among African American Men
Authors: Bloom Joan R. , Stewart Susan L. , Oakley-Girvans Ingrid , Banks Priscilla Jane , Chang Subo
Published: November 2006

Background: Many African American men have two major risk factors for prostate cancer. By ethnicity alone, they have twice the risk of Euro-American men of developing prostate cancer. Having a family history (brother or father with prostate cancer) also doubles their risk. The major hypotheses tested in this study are that men with a family history perceive their risk to be higher, are more worried about getting prostate cancer, and are more likely to have used cancer screening tests than men without such a history.

Methods: A sample of 208 African American men, ages 40 to 74 years, were recruited through relatives or friends whose prostate cancer diagnosis was reported to the California Cancer Registry during the years 1997 to 2001 and from churches and African American social groups. Following a screening interview to determine eligibility, 88 men with self-reported, first-degree family history of prostate cancer and 120 without such history were interviewed by telephone. Logistic regression was used to create models of perceived risk, prostate cancer worries, receipt of a digital rectal exam, and/or prostate-specific antigen (PSA) testing.

Results: Men with a self-reported family history of prostate cancer did not perceive their risk as higher than men without a family history, nor did they report more cancer worries. They were more likely to report having a recent PSA test, but not a digital rectal exam. Having a higher than average perceived risk was associated with younger age, a college education, and lower mental well-being, and reporting more prostate cancer worries and being more likely to have had a recent PSA test.

Conclusions: Although there continues to be controversy about PSA testing, these data suggest that African American men at above-average risk are inclined to be screened. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2167–73)
A Tailored Smoking, Alcohol, and Depression Intervention for Head and Neck Cancer Patients
Authors: Duffy Sonia A. , Ronis David L. , Valenstein Marcia , Lambert Michael T. , Fowler Karen E. , Gregory Lynn , Bishop Carol , Myers Larry L. , Blow Frederic C. , Terrell Jeffrey E.
Published: November 2006

Background: Smoking, alcohol use, and depression are interrelated and highly prevalent in patients with head and neck cancer, adversely affecting quality of life and survival. Smoking, alcohol, and depression share common treatments, such as cognitive behavioral therapy and antidepressants. Consequently, we developed and tested a tailored smoking, alcohol, and depression intervention for patients with head and neck cancer.

Methods: Patients with head and neck cancer with at least one of these disorders were recruited from the University of Michigan and three Veterans Affairs medical centers. Subjects were randomized to usual care or nurse-administered intervention consisting of cognitive behavioral therapy and medications. Data collected included smoking, alcohol use, and depressive symptoms at baseline and at 6 months.

Results: The mean age was 57 years. Most participants were male (84%) and White (90%). About half (52%) were married, 46% had a high school education or less, and 52% were recruited from Veterans Affairs sites. The sample was fairly evenly distributed across three major head and neck cancer sites and over half (61%) had stage III/IV cancers. Significant differences in 6-month smoking cessation rates were noted with 47% quitting in the intervention compared with 31% in usual care (P < 0.05). Alcohol and depression rates improved in both groups, with no significant differences in 6-month depression and alcohol outcomes.

Conclusion: Treating comorbid smoking, problem drinking, and depression may increase smoking cessation rates above that of usual care and may be more practical than treating these disorders separately. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2203–8)
New Marker of Colon Cancer Risk Associated with Heme Intake: 1,4-Dihydroxynonane Mercapturic Acid
Authors: Pierre Fabrice , Peiro Géraldine , Taché Sylviane , Cross Amanda J. , Bingham Sheila A. , Gasc Nicole , Gottardi Gaëlle , Corpet Denis E. , Guéraud Françoise
Published: November 2006

Background: Red meat consumption is associated with an increased risk of colon cancer. Animal studies show that heme, found in red meat, promotes preneoplastic lesions in the colon, probably due to the oxidative properties of this compound. End products of lipid peroxidation, such as 4-hydroxynonenal metabolites or 8-iso-prostaglandin-F2α (8-iso-PGF2α), could reflect this oxidative process and could be used as biomarkers of colon cancer risk associated with heme intake.

Methods: We measured urinary excretion of 8-iso-PGF2α and 1,4-dihydroxynonane mercapturic acid (DHN-MA), the major urinary metabolite of 4-hydroxynonenal, in three studies. In a short-term and a carcinogenesis long-term animal study, we fed rats four different diets (control, chicken, beef, and blood sausage as a high heme diet). In a randomized crossover human study, four different diets were fed (a 60 g/d red meat baseline diet, 120 g/d red meat, baseline diet supplemented with heme iron, and baseline diet supplemented with non-heme iron).

Results: DHN-MA excretion increased dramatically in rats fed high heme diets, and the excretion paralleled the number of preneoplastic lesions in azoxymethane initiated rats (P < 0.0001). In the human study, the heme supplemented diet resulted in a 2-fold increase in DHN-MA (P < 0.001). Urinary 8-iso-PGF2α increased moderately in rats fed a high heme diet (P < 0.0001), but not in humans.

Conclusion: Urinary DHN-MA is a useful noninvasive biomarker for determining the risk of preneoplastic lesions associated with heme iron consumption and should be further investigated as a potential biomarker of colon cancer risk. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2274–9)
Association between Nonsteroidal Anti-inflammatory Drug Use and the Incidence of Lung Cancer in the Iowa Women's Health Study
Authors: Hayes Jennifer H. , Anderson Kristin E. , Folsom Aaron R.
Published: November 2006

Background: Previous studies have suggested that use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) may be associated with reduced risk of lung cancer, but the data are inconsistent and are limited particularly with respect to the effects of aspirin, separate from other NSAIDs.

Methods: The Iowa Women's Health Study is a prospective cohort of 41,836 Iowa women ages 55 to 69 years old at baseline in 1986. NSAID use was assessed in 1992. Over 10 years of follow-up, 403 incident cases of lung cancer were identified. The association of incident lung cancer with current use of aspirin or non-aspirin NSAIDs was analyzed after adjustment for lung cancer risk factors. Hazard ratios (HR) were estimated using multivariate COX proportional hazards regression.

Results: There were 27,162 women in the analytic cohort. After controlling for age, education, alcohol intake, pack-years, smoking status, body mass index, and total fruit intake, the RR of women taking six or more aspirin weekly was 1.21 (95% confidence interval, 0.92-1.59). The HR was 1.23 for women taking six or more non-aspirin NSAIDs weekly (95% confidence interval, 0.92-1.65). There was no statistically significant trend by frequency of use for either aspirin (Ptrend = 0.22) or non-aspirin NSAIDs (Ptrend = 0.53). Analyses by histologic type and smoking status yielded similar null results. Information on dosage and duration of use were not available for this analysis.

Conclusion: These findings do not suggest that aspirin or other NSAIDs reduce risk of lung cancer in this cohort of postmenopausal women. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2226–31)
Effect of Mammography on Breast Cancer Risk in Women with Mutations in BRCA1 or BRCA2
Authors: Goldfrank Deborah , Chuai Shannon , Bernstein Jonine L. , Ramon y Cajal Teresa , Lee Johanna B. , Alonso M. Carmen , Diez Orland , Baiget Monserrat , Kauff Noah D. , Offit Kenneth , Robson Mark
Published: November 2006

Women who carry mutations in either the BRCA1 or BRCA2 genes are at risk for early-onset breast cancer and are recommended to begin screening mammography at age 25 to 30 years. Results of in vitro and animal studies suggest that BRCA1/BRCA2 mutation carriers are hypersensitive to ionizing radiation and possibly to radiation-induced breast cancer. This study was undertaken to investigate the association of low-dose radiation exposure from mammograms with breast cancer status in BRCA mutation carriers. One hundred sixty-two female mutation carriers provided information at time of genetic testing about exposure to mammograms before enrollment. Using unconditional logistic regression, breast cancer status was not associated with number of mammograms received before diagnosis (affected women) or ascertainment [unaffected women; adjusted odds ratio (OR), 0.94; P = not significant]. A larger group of 213 women provided information about lifetime number of mammograms. There was no association between mammogram exposure and risk in the group as a whole (adjusted OR, 1.04; P = not significant), although there was a modest association in BRCA1 carriers (adjusted OR, 1.08; P = 0.03). These findings indicate that screening mammography is unlikely to be associated with a large increase in breast cancer risk in this population. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2311–3)
Malignant Lymphomas in Autoimmunity and Inflammation: A Review of Risks, Risk Factors, and Lymphoma Characteristics
Authors: Smedby Karin Ekström , Baecklund Eva , Askling Johan
Published: November 2006

Certain autoimmune and chronic inflammatory conditions, such as Sjögren's syndrome and rheumatoid arthritis (RA), have consistently been associated with an increased risk of malignant lymphomas, but it is unclear whether elevated lymphoma risk is a phenomenon that accompanies inflammatory conditions in general. Likewise, it is debated whether the increased risk identified in association with some disorders pertains equally to all individuals or whether it varies among groups of patients with different phenotypic or treatment-related characteristics. It is similarly unclear to what extent the increased lymphoma occurrence is mediated through specific lymphoma subtypes. This update reviews the many findings on risks, risk levels, and lymphoma characteristics that have been presented recently in relation to a broad range of chronic inflammatory, including autoimmune, conditions. Recent results clearly indicate an association between severity of chronic inflammation and lymphoma risk in RA and Sjögren's syndrome. Thus, the average risk of lymphoma in RA may be composed of a markedly increased risk in those with most severe disease and little or no increase in those with mild or moderate disease. The roles of immunosuppressive therapy and EBV infection seem to be limited. Furthermore, RA, Sjögren's syndrome, systemic lupus erythematosus, and possibly celiac disease may share an association with risk of diffuse large B-cell lymphoma, in addition to well-established links of Sjögren's syndrome with risk of mucosa-associated lymphoid tissue lymphoma and of celiac disease with risk of small intestinal lymphoma. However, there is also obvious heterogeneity in risk and risk mediators among different inflammatory diseases. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2069–77)
Hepatitis C Virus and Risk of Lymphoma and Other Lymphoid Neoplasms: A Meta-analysis of Epidemiologic Studies
Authors: Dal Maso Luigino , Franceschi Silvia
Published: November 2006

The present meta-analysis was conducted to evaluate the strength and the consistency of the association between hepatitis C virus (HCV) infection and non–Hodgkin lymphoma (NHL) and other lymphoid neoplasms. Only studies with ≥100 cases which were also adjusted for sex and age were included. Fifteen case-control studies and three prospective studies contributed to present analysis, nine of which had not been included in previous meta-analyses. We calculated the pooled relative risks (RR) with corresponding 95% confidence intervals (95% CI), as a weighted average of the estimated RRs by random-effect models. The pooled RR of all NHL among HCV-positive individuals was 2.5 (95% CI, 2.1-3.0), but substantial heterogeneity was found between studies and by study design. Pooled RRs were 2.5 (95% CI, 2.1-3.1) in case-control studies and 2.0 (95% CI, 1.8-2.2) in cohort ones. The strongest source of heterogeneity seemed to be the prevalence of HCV among NHL-free study subjects (RR for NHL among HCV-positive individuals 3.0 and 1.9, respectively, for ≥5% and <5% HCV prevalence). RRs were consistently increased for all major B-NHL subtypes, T-NHL, and primary sites of NHL presentation. Thus, previous suggestions that the RRs for HCV differed by NHL subtype were not confirmed in our meta-analysis. Associations weaker than with NHL were found between HCV infection and Hodgkin's lymphoma (RR, 1.5; 95% CI, 1.0-2.1) and multiple myeloma (RR, 1.6; 95% CI, 0.7-3.6), but they were based on much fewer studies than NHL. The etiologic fraction of NHL attributable to HCV varies greatly by country, and may be upward of 10% in areas where HCV prevalence is high. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2078–85)