bluuebunny/crossref_metadata_2025 huggingface dataset:
A mean ergodic theorem of an amenable group action
Authors: Mohari Anilesh
Published: April 2014

We consider a sequence of weak Kadison–Schwarz maps τn on a von-Neumann algebra ℳ with a faithful normal state ϕ sub-invariant for each (τn, n ≥ 1) and use a duality argument to prove strong convergence of their pre-dual maps when their induced contractive maps (Tn, n ≥ 1) on the GNS space of (ℳ, ϕ) are strongly convergent. The result is applied to deduce improvements of some known ergodic theorems and Birkhoff's mean ergodic theorem for any locally compact second countable amenable group action on the pre-dual Banach space ℳ*.
STRESS DISTRIBUTION WITHIN THE PLANTAR APONEUROSIS DURING WALKING — A DYNAMIC FINITE ELEMENT ANALYSIS
Authors: LIN SHIH-CHERNG , CHEN CARL PAI-CHU , TANG SIMON FUK-TAN , CHEN CHENG-WEI , WANG JIUN-JIE , HSU CHIH-CHIN , HSIEH JUI-HSIANG , CHEN WENG-PIN
Published: April 2014

Excessive and repeated loading of the plantar aponeurosis (PA) is believed to be the most likely risk factor for developing plantar fasciitis. This study provided a novel approach to investigate the biomechanical responses of the PA during the entire stance phase of gait. One healthy subject was recruited for all the experimental measurements to validate the approach in this study. A three-dimensional (3D) finite element (FE) foot model representing this individual, with emphasis on the PA as a transversely isotropic tissue, was constructed. Kinematic data of foot motions were collected during a walking trial to serve as input conditions for the model. A peak tensile force of 922 N on the PA was found during the terminal-stance phase rather than during the mid-stance phase. The maximal peak von Mises stresses in the PA from the medial to lateral regions of the foot measured 15.61, 14.98 and 11.4 MPa at 74%, 77% and 82% of the stance phase, respectively. These peak stresses all occurred near the proximal calcaneal bony insertion site of the PA and correspond closely with the location where plantar fasciitis develops. Future work should include more subjects and clinical trials before applying these findings to the treatment of plantar fasciitis.
NUMERICAL STUDY OF BIDIRECTIONAL GLENN WITH UNILATERAL PULMONARY ARTERY STENOSIS
Authors: ZHAO XI , LIU YOUJUN , DING JINLI , BAI FAN , REN XIAOCHEN , MA LIANCAI , XIE JINSHENG , ZHANG HAO
Published: April 2014

Purpose: Hypoplastic left heart syndrome (HLHS) is a congenital heart disease and is usually associated with pulmonary artery stenosis. The superior vena cava-to-pulmonary artery (bidirectional Glenn) shunt is used primarily as a staging procedure to the total cava-to-pulmonary connection for single-ventricle complex. When HLHS coexists with pulmonary artery stenosis, the surgeons then face a multiple problem. This leads to high demand of optimized structure of Glenn surgery. The objective of this article is to investigate the influence of various anastomotic structures and the direction of superior vena cava (SVC) in Glenn on hemodynamics under pulse inflow conditions and try to find an optimal structure of SVC in Glenn surgery with unilateral pulmonary artery stenosis.

Method: First, 3D patient-specific models were constructed from medical images of a HLHS patient before any surgery by using the commercial software Mimics, and another software Free-form was used to deform the reconstructed models in the computer. Four 3D patient-specific Glenn models were constructed: model-1 (normal Glenn), model-2 (lean the SVC back to the stenotic pulmonary artery), model-3 (lean the SVC towards the stenotic pulmonary artery), model-4 (add patch at junction of the SVC toward stenosis at pulmonary artery). Second, a lumped parameter model (LPM) was established to predict boundary conditions for computational fluid dynamics (CFD). In addition, numerical simulations were conducted using CFD through the finite volume method. Finally, hemodynamic parameters were obtained and evaluated.

Results: It was showed that model-4 have relatively balanced vena cava blood perfusion into the left pulmonary artery (LPA) and right pulmonary artery (RPA), this may be due to less helical flow and the patch at junction of the SVC. Near stenosis of pulmonary artery, model-4 performed with the higher wall shear stress (WSS), which would benefit endothelial cell function and gene expression. In addition, results showed that model-4 performed with the lower oscillatory shear index (OSI) and wall shear stress gradient (WSSG), which would decrease the opportunity of vascular intimal hyperplasia.

Conclusion: It is benefited that surgeons adds patch at junction of the SVC towards stenosis at pulmonary artery. These results can impact the surgical design and planning of the Glenn surgery with unilateral pulmonary artery stenosis.
MEASURING CULTURAL DYNAMICS THROUGH THE EUROVISION SONG CONTEST
Authors: GARCÍA DAVID , TANASE DORIAN
Published: April 2014

Measuring culture and its dynamics through surveys has important limitations, but the emerging field of computational social science allows us to overcome them by analyzing large-scale datasets. In this paper, we study cultural dynamics through the votes in the Eurovision song contest, which are decided by a crowd-based scheme in which viewers vote through mobile phone messages. Taking into account asymmetries and imperfect perception of culture, we measure cultural relations among European countries in terms of cultural affinity. We propose the Friend-or-Foe coefficient, a metric to measure voting biases among participants of a Eurovision contest. We validate how this metric represents cultural affinity through its relation with known cultural distances, and through numerical analysis of biased Eurovision contests. We apply this metric to the historical set of Eurovision contests from 1975 to 2012, finding new patterns of stronger modularity than using votes alone. Furthermore, we define a measure of polarization that, when applied to empirical data, shows a sharp increase within EU countries during 2010 and 2011. We empirically validate the relation between this polarization and economic indicators in the EU, showing how political decisions influence both the economy and the way citizens relate to the culture of other EU members.
SERVICE BUSINESS MODEL AND SERVICE INNOVATIVENESS
Authors: CHENG COLIN C. J. , SHIU ERIC C. C. , DAWSON JOHN A.
Published: April 2014

Service innovativeness has been hailed as a key success factor in being able to differentiate a new service from its competing offerings. In spite of a number of literatures suggesting the impact that a service business model can have on service innovativeness, no comprehensive and empirical study has examined the relationship between the distinctive design themes of a service business model and service innovativeness. This paper fills the research gap by conducting a series of pilot tests and then the subsequent questionnaire survey on top service firms in Taiwan. Results based on 211 responding service firms indicate that the novelty-centred business model has a U-shaped effect on service innovativeness, while the efficiency-centred business model has an inverted U-shaped effect on service innovativeness. Theoretical and managerial implications of these key findings are discussed.
INVESTIGATION OF DYE-REGENERATION KINETICS AT DYE-SENSITIZED p-TYPE CuCrO2 FILM/ELECTROLYTES INTERFACE WITH SCANNING ELECTROCHEMICAL MICROSCOPY
Authors: ALEMU GETACHEW , ZHANG BINGYAN , LI JUNPENG , XU XIAOBAO , CUI JIN , SHEN YAN , WANG MINGKUI
Published: April 2014

The power conversion efficiency of p-type dye-sensitized solar cells (DSSC) is determined by the kinetics of hole injection and dye-regeneration reaction at the dye/electrolyte interface. In this work, the photochemical regeneration kinetics of dye adsorbed on CuCrO 2 mesoporous film was investigated by using scanning electrochemical microscopy with feedback mode. Organic P1 and C343 sensitizers in combination with iodide-based and thiolate-based electrolytes were selected to understand the effect of sensitizers and redox shuttles on dye-regeneration process. A fast regeneration kinetic rate constant was confirmed in thiolate-based sample compared with iodide-based electrolyte, indicating that the organic redox shuttle was an efficient mediator to optimize the performance of p-type DSSC.
A parametrized version of the Borsuk–Ulam–Bourgin–Yang–Volovikov theorem
Authors: Matschke Benjamin
Published: April 2014

We present a parametrized version of Volovikov's powerful Borsuk–Ulam–Bourgin–Yang type theorem, based on a new Fadell–Husseini type ideal-valued index of G-bundles which makes computations easy.

As an application we provide a parametrized version of the following waist of the sphere theorem due to Gromov, Memarian, and Karasev–Volovikov: Any map f from an n-sphere to a k-manifold (n ≥ k) has a preimage f-1(z) whose epsilon-neighborhoods are at least as large as the epsilon-neighborhoods of the equator Sn-k (if n = k we further need that f has even degree).
ADSORPTION CHARACTERISTICS AND HEAT OF ADSORPTION MEASUREMENTS OF R-134a ON GRANULAR ACTIVATED CARBON
Authors: ATTALLA M. , SADEK S. , ABD EL-FADEEL W.
Published: April 2014

The objective of this study is to investigate the adsorption characteristics of granular activated carbon GAC/R-134a pair in the temperature range of 20–60°C and pressure up to 10 bars. The Dubinin–Astakhov adsorption equilibrium model is fit to experimental data with acceptable error limit. The pressure–temperature–concentration (P–T–X) diagram of the pair is also presented. The isosteric heat of adsorption of R-134a on AC has been calculated using the Clausius–Clapeyron equation as a function of adsorption capacity. The maximum adsorption capacity was found to be 1.92 kgR134a/kgcarbon at 20°C after 1200 s. The experimental results also shows that the increase of heat transfer area improves the adsorption capacity per kg of adsorber, which lead to the design of a finned tubes heat exchanger adsorption unit.
Physical-chemical properties and metal budget of Au-transporting hydrothermal fluids in orogenic deposits
Authors: Garofalo Paolo S. , Fricker Mattias B. , Günther Detlef , Bersani Danilo , Paolo Lottici Pier
Published: April 2014

We use a set of analytical techniques for fluid inclusion analysis to determine the bulk properties of the ore fluids from five orogenic gold deposits. The most common ore fluid is a low salinity (0.4–6.5 wt% NaCl) two- to three-phase aqueous-carbonic fluid. Its
T
h(total) range is 200–400 °C, and total homogenization occurs by bubble or liquid disappearance. A less common aqueous fluid of similar bulk salinity and
T
h(total) is also documented. Microchemical data show that the ore fluid in the five deposits is chemically uniform and made of Na, subordinate K and B and minor to trace amounts of Cu, As, Li, Sr, Rb, Ba, Cs, Sb and Au (range 0.5–5 µg/g). Thermodynamic modelling carried out for one of the studied deposits indicates that the ore fluid was in equilibrium with vein minerals at the time of gold deposition, and that its vapour phase was distinctly enriched in Au, B, As and Sb. The proposed mechanism of gold precipitation is a combination of fluid decompression and boiling. Combining these results with 3D geometrical reconstructions of one of the studied deposits (Sigma), we estimate that a minimum ore fluid volume of
c.
0.1–1.0 km
3
is sufficient to generate a world-class orogenic deposit.
Bacterial Multidrug Efflux Transporters
Authors: Delmar Jared A. , Su Chih-Chia , Yu Edward W.
Published: April 2014

Infections caused by bacteria are a leading cause of death worldwide. Although antibiotics remain a key clinical therapy, their effectiveness has been severely compromised by the development of drug resistance in bacterial pathogens. Multidrug efflux transporters—a common and powerful resistance mechanism—are capable of extruding a number of structurally unrelated antimicrobials from the bacterial cell, including antibiotics and toxic heavy metal ions, facilitating their survival in noxious environments. Transporters of the resistance-nodulation-cell division (RND) superfamily typically assemble as tripartite efflux complexes spanning the inner and outer membranes of the cell envelope. In Escherichia coli, the CusCFBA complex, which mediates resistance to copper(I) and silver(I) ions, is the only known RND transporter specific to heavy metals. Here, we describe the current knowledge of individual pump components of the Cus system, a paradigm for efflux machinery, and speculate on how RND pumps assemble to fight diverse antimicrobials.
Advancing Adsorption and Membrane Separation Processes for the Gigaton Carbon Capture Challenge
Authors: Wilcox Jennifer , Haghpanah Reza , Rupp Erik C. , He Jiajun , Lee Kyoungjin
Published: April 2014

Reducing CO2 in the atmosphere and preventing its release from point-source emitters, such as coal and natural gas–fired power plants, is a global challenge measured in gigatons. Capturing CO2 at this scale will require a portfolio of gas-separation technologies to be applied over a range of applications in which the gas mixtures and operating conditions will vary. Chemical scrubbing using absorption is the current state-of-the-art technology. Considerably less attention has been given to other gas-separation technologies, including adsorption and membranes. It will take a range of creative solutions to reduce CO2 at scale, thereby slowing global warming and minimizing its potential negative environmental impacts. This review focuses on the current challenges of adsorption and membrane-separation processes. Technological advancement of these processes will lead to reduced cost, which will enable subsequent adoption for practical scaled-up application.
Diamond Formation: A Stable Isotope Perspective
Authors: Cartigny Pierre , Palot Médéric , Thomassot Emilie , Harris Jeff W.
Published: April 2014

Primarily on the basis of C, N, S, and O stable isotope systematics, this article reviews recent achievements in understanding diamond formation and growth in Earth's mantle. Diamond is a metasomatic mineral that results from either the reduction or oxidation of mobile C-bearing liquids (fluids or melts) that intrude preexisting lithologies (eclogites, peridotites, and metamorphic rocks). This process seems ubiquitous, as it occurs over a large range of depths and extends through time. Diamond-forming carbon derives mainly from the convective asthenosphere. Most of its isotopic anomalies reflect fractionation processes in the lithospheric mantle, which are attributed to diamond precipitation itself and/or a mineralogical control occurring prior to diamond precipitation. Evidence for a mineralogical control would be the decoupling of the 15N/14N ratios in eclogitic diamond from other tracers of subduction in inclusions in the same diamond. C isotope anomalies related to subduction are rare and are probably best seen in diamonds from the transition zone.
Planetary Reorientation
Authors: Matsuyama Isamu , Nimmo Francis , Mitrovica Jerry X.
Published: April 2014

Planetary bodies can undergo reorientation due to mass redistribution associated with internal or external processes such as convection or impacts. Mass redistribution produces perturbations to the inertia tensor, and the planet must reorient to adjust to the new orientation of the maximum principal axis. The amount of reorientation depends on the competing sizes of the applied load and the remnant bulge. For tidally deformed satellites in synchronous rotation, the slow rotation and correspondingly small remnant bulge makes them prone to reorientation. Reorientation can generate gravity and topography perturbations and large tectonic stresses. Observational constraints based on gravity, tectonic, and paleomagnetic data suggest that many Solar System bodies appear to have undergone significant reorientation.
Under the Thumb of History? Political Institutions and the Scope for Action
Authors: Banerjee Abhijit V. , Duflo Esther
Published: April 2014

This article discusses the two leading views of history and political institutions. For some scholars, institutions are mainly products of historical logic, whereas for others, accidents, leaders, and decisions have a significant impact. We argue that although there is clear evidence that history matters and has long-term effects, there are not enough data to help us distinguish between the two views. Faced with this uncertainty, what is a social scientist to do? We argue that given the possibility that policy decisions indeed make a difference, it makes sense to assume they do and to try to improve policy making.
Structural Features of Nano-Scale Damascene Copper Lines after Annealing in Wide Temperature Range
Authors: Konkova Tatyana N. , Mironov Sergey Yu. , Ke Yiqing , Onuki Jin
Published: April 2014

Grain structure and texture evolved in damascene nano-scale copper lines after annealing in a wide temperature interval of 200oC-500oC were analyzed. Electron backscatter diffraction (EBSD) technique was used for rigorous investigation of the overburden layer, upper and bottom parts of the lines. In all cases, the microstructures were found to stabilize after achieving the same level of total grain-boundary area per unit volume. The grain growth behavior was supposed to be governed by the pinning effect of second-phase particles entrapped during the electrodeposition process.
Copper Seed Layer Wet Etching for 3D Integration
Authors: Gabette Laurence , Kachtouli Riadh , Segaud Roselyne , Besson Pascal
Published: April 2014

This study focuses on the copper seed layer wet etch for 3D Integration. Indeed, designs such as Redistribution Layer or copper Pillars involved in advanced packaging commonly use copper seed layer to permit copper ECD growth. In order to isolate patterns, the copper seed layer needs to be totally removed with a controlled undercut. The copper wet etch chemistry and kinetic are studied on blanket wafers together with patterned wafers. The impacts of wet etch on ECD copper such as roughness and copper loss are quantified. A specific issue resulting in a random defectivity on Cu-SnAg bumps is described and a containment solution is given. Finally, impact of pattern density on seed layer etch rate is investigated.
Nitrate Removal by Electrolysis Using Cu/BDD Electrode Cathode
Authors: Ribeiro Mildred Caroline Elis , Couto Andrea Boldarini , Ferreira Neidenei Gomes , Baldan Mauricio Ribeiro
Published: April 2014

Copper particles were deposited in the potentiostact mode and under UV irradiation on the boron doped diamond (BDD) surface. The copper deposited presented high density and uniformity all over crystal faces. This behavior may be associated with its semiconductor character that promoted additional photogenerated electrons enhancing the copper reduction reaction. This modified electrode was used as a cathode electrode on the studies of the nitrates removal from aqueous solutions by electrolysis in an undivided electrochemical cell and BDD as an anode electrode. The nitrate reduction was analyzed at three differents initial pH (neutral, acid and basic). The nitrate reduction rate did not increase linearly as a function of current densities using potassium sulphate as the electrolyte (neutral pH). In the present experiment, the optimum current density was 20 mA/cm2. The nitrate reduction decreased from 150 to 63.8 ppm. Regarding to the influence of initial pHs used, it could be conclude that high value of pH favours the nitrate electroreduction. This result may be associated with the higher competition between the H+ and the NO3- ions by electrons on the cathode surface, causing a decrease in the efficiency of electrolysis.
Removal of Radioactive Cs Using Aqueous Sodium Metasilicate with Reduced Volumes of Waste Solution
Authors: Ueda Yoshikatsu , Tokuda Yomei , Goto Hiroshi , Kobayashi Tomoyuki , Ono Yuji
Published: April 2014

Remediation of materials contaminated with a radioactive material such as 137Cs is important. Here, we report on the effectiveness of an aqueous sodium metasilicate prepared with a microbubble crushing process (SMC) for the removal of radioactive 137Cs from granule conglomerates and nonwoven cloth. A 137Cs removal ratio of 78% was achieved for the nonwoven cloth sample, and multiple washings at low SMC concentrations were effective. In addition, the volume of the waste solution could be reduced by neutralizing the SMC and using gelation to remove the radioactive material. The decontamination is shown to be more efficient than that with sodium hydroxide, even for washing granule conglomerates.
Performance Analysis of Solid Oxide Electrolysis Cells for Syngas Production
Authors: Kazempoor Pejman , Braun Robert J.
Published: April 2014

There is a significant effect from operating parameters on solid oxide electrolysis cell (SOEC) performance. The object of this research is to simulate the complex phenomena inside a planar SOEC in order to identify the best operating conditions. The model involves an intermediate fidelity of the electrochemical and thermo-fluid phenomena inside the cell. An example of the model validation for an electrolyte supported SOEC is presented here. The model is then employed to investigate various parameters such as temperature, fuel composition, flow rates and H2/CO ratio related to SOEC performance as well as hydrogen and syngas production. It has been observed that the reversible water-gas-shift (rWGS) reaction plays an important rule inside the fuel channels. Although the operating temperature, fuel composition and flow rates have direct effect on SOEC performance and power consumption, their influence on rWGS is more significant.
Anodes Based on Pt Doped Titanium Sub-Oxides
Authors: Kasian Olga , Luk'yanenko Tatiana V. , Amadelli Rossano , Velichenko Alexander
Published: April 2014

Effects of thermal treatment and amount of electrodeposited Pt on electrocatalytic activity of materials based on platinized Ebonex® were investigated. Surface morphology, phase and chemical composition were found to be strongly depended on temperature of electrode preparation. Crystallite size of platinum coating was shown to increase with temperature of thermal treatment. At the same time decrease in strains in coating with temperature was observed providing better mechanical stability of the thermally treated electrodes. Materials based on platinized Ebonex® were shown to be n-type semiconductors that affect their electrochemical behavior. An increase in the flatband potential with temperature, and the donor concentration decrease were observed due to both oxidation of Pt and TiO2 formation. Some of platinized Ebonex anodes could be recommended for application in a trivalent chromium electroplating bath owing to low rates of Cr(III) electrooxidation and extended service life.
Graphene Growth on Electrodeposited Polycrystalline Copper and Ruthenium
Authors: Pigliafreddo Dario , Magagnin Luca , Nobili Luca , Carraro Carlo , Maboudian Roya
Published: April 2014

Graphene grown by CVD on Cu foils has generated interest due to low cost and the prospect of large-area monolayer coverage. The initial nucleation and growth dynamics of graphene play a critical role in determining the final film quality. In this work, we investigate the effects of the electrochemical synthesis onto graphene quality, showing the influence of the Cu-Ru interdiffusion. The growth of good quality graphene layers is also discussed in terms of the role played by grain boundaries and diffusion at the grain boundaries. This comparison shows that the graphene having the best quality is produced using a ruthenium sandwich covering a copper core. This setting avoids contaminations from evaporation and recondensation of copper during thermal cycling due to the CVD process.
Comparative Study of the Growth of CNTs on Stainless Steel with and without the External Catalyst
Authors: Hashempour Mazdak , Vicenzo Antonello , Bestetti Massimiliano
Published: April 2014

Multi-walled carbon nanotubes were synthesized on 316 stainless steel substrate by chemical vapor deposition through two different methods: 1- without use of any external catalyst and using ethylene as the carbon precursor and 2- using ferrocene as an external source of catalyst particles, dissolved in toluene, as the carbon precursor. Carbon nanotubes grown by the two methods were characterized by scanning and transmission electron microscopy and X-ray diffraction methods and were compared subsequently to determine certain characteristics of each method. Good coverage and homogeneity was observed in both cases. However, the carbon layer was thicker and denser in externally catalyzed samples. Two different mechanisms, namely, base and tip modes, were observed for the nanotubes growth, each with particular characteristics stemming from the synthesis methods. Surface nano-features and external catalyst behavior were found to have the dominant role in determining the morphology of carbon filaments in intrinsically and externally catalyzed samples, respectively.
Fabrication of Graphene by Electrochemical Exfoliation in Alkaline Electrolytes
Authors: Chang Li-Chung , Hsieh Yu-Chi , Chen Yong-Min , Wu Pu-Wei , Lee Jyh-Fu
Published: April 2014

Fabrication of graphene was demonstrated by electrochemical exfoliation of graphite in an ammonium hydroxide solution. The processing parameter of applied voltage was optimized to accomplish graphene productivity and desired chemical composition. Images from the atomic force microscopy showed graphene sheets with lateral sizes of several hundred nanometers. Images from the transmission electron microscopy indicated the existence of stacked graphene sheets with thickness of a few graphene layers. Raman spectroscopy confirmed variation of as-synthesized graphene and bulk graphite. X-ray photoemission spectroscopy suggested the formation of graphene oxide at large voltage.
Cold Gas Sprayed TiO2-Based Electrodes for the Photo-Induced Water Oxidation
Authors: Herrmann-Geppert Iris , Bogdanoff Peter , Gutzmann Henning , Dittrich Thomas , Emmler Thomas , Just Regina , Schieda Mauricio , Gärtner Frank , Klassen Thomas
Published: April 2014

Cold gas spraying (CGS) is presented as an innovative approach to deposit semiconductor particles onto substrates in order to form photoelectrodes for electrochemical applications. Thin layers of TiO2 (P25-20 by Evonik Industries) are deposited onto titanium substrates (TiO2-CGS films) at different temperatures of the gas carrier within the CGS process (300 - 1000 °C). Structural characterization reveals unchanged bulk properties of the TiO2 nanoparticles. Clearly, the short duration time of the CGS process hinders crystalline bulk changes of the TiO2 particles in the hot gas stream. However, surface photovoltage measurements indicate that the CGS process modified defect states at the surface when exposed to different gas temperature. In photoelectrochemical measurements TiO2-CGS films yield seven times higher photocurrents and IPCE values than comparable films prepared by the well-established doctor blade technique. The increased efficiency might be due to an enhanced particle to substrate bonding caused by particles welding to the metallic substrate during the cold gas spray process.
Improvement in Photo-Potential Characteristics of TiO2 Electrode Assembling to Marine Microbial Fuel Cell
Authors: Tamura Sho , Morita Motoaki , Motoda Shinichi , Uematsu Susumu , Shinohara Tadashi
Published: April 2014

It has been reported that the potential of stainless steel (S.S.) ennobles to 400 mV by the formation of biofilm in seawater. This phenomenon can lead to the development of a battery by coupling an active counter electrode. On the other hand, TiO2 is well known as an n-type semiconductor which exhibits the photo-catalytic effect under the UV irradiation. When a TiO2 coated metal is irradiated by the UV light, excited electrons are transferred to the base metal, this phenomenon leads to the active shift of electrode potential. This effect can be applied to microbial fuel cell as a non-sacrifice electrode. We have investigated the electrochemical characteristics of the marine microbial fuel cell (MMFC) composed of biofilm covered stainless steel cathode and TiO2 anode in seawater. However, it is needed to improve the photo-potential characteristics of electrodes for the practical application.The present work attempted to improve the battery performance by assembling the double layered TiO2 anode electrode.Results from experimental, by using the double layered anode for MFC, cell voltage increases 120 mV and maximum power density enhances 1.4 times compared with the value of single layered one coated by squeegee printing method. The double layered electrode has anatase / rutile hetero-junction, therefore it promotes the electron transfer between base metal and TiO2 coating interface. In addition, the double layered electrode has a high durability against the cyclic irradiation because TiO2 intermediate layer behaves as a corrosion protective barrier which suppresses the direct contact between electrolyte and base metal.
Synthesis and Preliminary Photoelectrochemical Study of Silver Antimony Sulfide Semiconductor
Authors: Parajuli Suman , Chhetri Pushpa , Stephenson Wess Lee , Alpuche-Aviles Mario A
Published: April 2014

Silver antimony sulfide (Ag3SbS3) has been synthesized in a solid state route from silver, antimony and sulfur powder precursors in sealed tube under an argon atmosphere and with a customized temperature program. The product was characterized by powder X-ray diffraction (XRD) and found to be pyrargyrite, Ag3SbS3 with a small band gap (Eg) of 2.0 eV and we investigated its ability to absorb solar energy and produce electron-hole (e-h+) pairs for water splitting. We report a photoelectrochemical study with films on fluorine-doped tin oxide (FTO) substrate and with bulk solid electrodes prepared from pieces of pyrargyrite grown. The response from the solid electrodes was significantly different from the photocurrent observed from the films.
Mass Transport and Electrochemical Phenomena Influencing the Pitting and Repassivation of Stainless Steels in Neutral Chloride Media
Authors: Srinivasan Jayendran , McGrath Michael J. , Kelly Robert G.
Published: April 2014

Mass transport and electrochemical parameters affecting pitting stability and repassivation in neutral chloride media were measured using the artificial pit electrode technique and the effect of different variables was studied. Sensitivity analysis showed that accurate estimation of the critical pit stability product, (i*x)crit is necessary for correctly estimating the maximum pit size that can be attained on a stainless steel surface under a thin electrolyte film. The value of (i*x)crit is directly related to the surface concentration and is some fraction of the value when a salt film is present (i*x)sf. A graphical method to determine the surface concentration at the edge of pit stability was developed in terms of diffusive transport by relating repassivation potential (Erp) to pit stability. It was seen that the value of 60-80% commonly accepted in the literature as the minimum degree of saturation for pitting stability may in fact overestimate the actual value. Further, it was noted that redox reactions involving dissolved minor alloying elements may significantly affect the measurement of Erp in some systems.
Effect of Applied Stress on Dissolution Morphology and Pit Initiation Behavior of MnS Inclusion in Stainless Steel
Authors: Shimahashi Naoya , Muto Izumi , Sugawara Yu , Hara Nobuyoshi
Published: April 2014

Microelectrochemical measurements were carried out to ascertain the effect of stress on the dissolution morphology and pit initiation behavior of (Mn,Cr)S inclusions, which contained around 15 at. % chromium. Under anodic polarization, the selective dissolution of MnS and the composition change from the (Mn,Cr)S to CrS occurred in 1.5 mol kg-1 MgCl2. No stable pit was initiated under no applied stress, even though the MnS dissolution and the formation of meta-stable pits were observed. Under applied stress, a stable pit was initiated in the potential range of the MnS dissolution, and small cracks that were perpendicular to a tensile direction were generated. The cracks were thought to be induced by a mechano-chemical reaction, and propagated to the steel under the inclusion. The steel matrix was then exposed to the solutions, and stable pitting was initiated at the inclusions under applied stress.
Chloride Ion Concentration Effects on Passivity Breakdown in Magnesium
Authors: Williams Geraint , Dafydd Hefin , Subramanian Raman
Published: April 2014

An empirically derived dependence of the breakdown potential (Eb) of pure magnesium (Mg) on chloride ion concentration ([Cl-]) is described. For commercial purity Mg, which undergoes spontaneous breakdown in the absence of external polarization, Eb is established by following time-dependent changes in free corrosion potential (Ecorr). The localized corrosion behaviour of Mg, characterized by in-situ scanning vibrating electrode studies prior to and following breakdown, is employed to explain the Ecorr vs. time characteristics. For high purity Mg, which remains passive at pH 11 at all chloride concentrations ≤ 2 mol dm-3, Eb values are measured by means of a potentiodynamic method. In both cases a dependence of Eb on [Cl-] is established such that Eb = A + B log10[Cl-], where the value of B is -0.11 V per decade. The origin of the log10 relationship with [Cl-] is discussed in terms of the solubility product of magnesium hydroxide.
Modeling the Influence of Microstructure on Corrosion Pit Growth and Resulting Stress Concentration
Authors: Kota Nithyanand , Qidwai Siddiq M , DeGiorgi Virginia G
Published: April 2014

Localized corrosion like pitting corrosion can result in catastrophic failure of components due to transition of pits to stress corrosion cracks under loading. This transition is a product of pit morphology and mechanical behavior of the metal leading to regions of stress concentration from where cracks emanate. Fundamentally, both factors are dependent on the underlying microstructure, with pit morphology resulting from differences in growth rates across grains, and mechanical behavior resulting from elastic and plastic anisotropies across crystal orientations. This work presents a decoupled stress corrosion analysis, where at first pit growth simulations are performed at various locations in a steel microstructure, while taking into account the effect of microstructure through variation in corrosion potential. Subsequently the pit geometries are accommodated in mechanical loading simulations along with the underlying microstructure and anisotropic material properties to calculate stress distributions around the pit.
Catalytic Activity of (001)-AO and BO2 Surfaces of Transition Metal Perovskites: Case of LaCrO3
Authors: Gadre Milind , Lee Yueh-Lin , Shao-Horn Yang , Morgan Dane
Published: April 2014

Complex oxides such as transition metal perovskites, particularly ABO3 perovskites of the type ABO3 (A=La, B= transition metal, O=oxygen) are promising catalysts for the aqueous oxygen reduction reaction (ORR), with potential application in in Alkaline Fuel Cell cathodes. There is a significant interest in using atomistic simulations to help design cathode materials through the study of the nature of surface binding. However, modeling of ORR on perovskite oxides has been previously restricted only to BO2-terminated surfaces, although in practice a mixture of both AO and BO2 terminations may exist, as the exact nature of surface termination for thin-film catalyst electrodes is difficult to synthesize as well as characterize. In this study we use Density Functional Theory based thermodynamic modeling to probe the differences in the binding of oxygen (O) and hydroxyl species (OH and OOH,) on the (001)-LaO and (001)-BO2 terminations, with the focus on the material LaCrO3. We show that in the relevant aqueous conditions for alkaline fuel cell cathodes, surface species *OH, *OOH and *O bind ~2eV more strongly to the LaO-termination compared to the CrO2-terminated surfaces, and therefore, when the LaO termination is stable, can potentially passivate the oxygen reduction and evolution reaction activity of the thin-films of LaCrO3.
Evaluation of Transparent Polyimide Film as a Biological Cell Culture Sheet with Microstructures
Authors: Maenosono Hirotaka , Saito Hirofumi , Nishioka Yasushiro
Published: April 2014

We evaluated a transparent PI film as a cell culture sheet in comparison with films of PA and PEEK formed, which have been previously used in cell culture sheets. We fabricated microtrenches with a width and depth of 5 μm on these polymer films by hot embossing, and then cultivated OP9 stromal marrow cells on the sheets. The cells grown on the transparent PI were easily observed using an optical microscope.
Aqueous Electrochemical Synthesis of Stable Silver Metal Nanoparticles onto a Chitosan Matrix on Stainless Steel
Authors: Halada Gary P. , Jha Prashant , Cuiffo Michael , Acquah Kweku , Carl Sarah
Published: April 2014

Silver nanoparticles are formed through an environmentally-benign electrochemically-driven method on type 304 stainless steel electrodes, with potential energy and biomedical applications. An electrochemically-deposited initial layer of chitosan strongly adheres to the passive layer formed on the 304 stainless steel electrodes. Electrochemical deposition from a subsequent silver nitrate solution forms nanoparticles in the size range of 10 to 200 nm depending on processing parameters, in situ, rapidly and at room temperature. The overall coating has been shown to possess mechanical cohesiveness, flexibility, and durability, including remarkable stability with atmospheric exposure (both of the matrix and the nanoparticles contained within). Infrared, Raman and UV-vis spectroscopies, synchrotron X-ray absorption, and electron microscopy have been used to characterize the materials and indicate that chitosan provides protection from environmental degradation (as well as promotes formation of the nanoparticles).
Towards Molecular Electronics: Using Solution-Based Methods to Deposit Nanowires
Authors: Ellsworth Ashley A. , Borner Katherine , Yang Jing , Walker Amy V
Published: April 2014

Electroless nanowire deposition on micropatterned substrates (ENDOM) is a promising technique by which to direct the growth of nanowires. Cu, Pd, Ni and Ag nanowires have been grown on patterned –OH/–CH3 SAMs by exploiting the different reaction rates of electroless deposition on –CH3 and –OH terminated SAMs. Initially the nanoparticles nucleate at the interface of the –CH3 and –OH terminated SAMs, which coalesce into a polycrystalline, uniform nanowire. The dimensions of the deposited nanowires are controlled by the reagent concentrations, deposition bath pH, deposition temperature, deposition time and identity of the reducing agent. Finally we demonstrate that chemical bath deposition can also be used to direct the growth of semiconducting nanowires in a similar process to ENDOM.
Animals Models of Gastrointestinal and Liver Diseases. Animal models of alcohol-induced liver disease: pathophysiology, translational relevance, and challenges
Authors: Mathews Stephanie , Xu Mingjiang , Wang Hua , Bertola Adeline , Gao Bin
Published: April 2014

Over the last four decades, chronic ethanol feeding studies in rodents using either ad libitum feeding or intragastric infusion models have significantly enhanced our understanding of the pathogenesis of alcoholic liver disease (ALD). Recently, we developed a chronic plus binge alcohol feeding model in mice that is similar to the drinking patterns of many alcoholic hepatitis patients: a history of chronic drinking and recent excessive alcohol consumption. Chronic+binge ethanol feeding synergistically induced steatosis, liver injury, and neutrophil infiltration in mice, which may be useful for the study of early alcoholic liver injury and inflammation. Using this chronic+binge model, researchers have begun to identify novel mechanisms that participate in the pathogenesis of alcoholic liver injury, thereby revealing novel therapeutic targets. In this review article, we briefly discuss several mouse models of ALD with a focus on the chronic+binge ethanol feeding model.
Regulation of hepatic insulin receptor activity following injury
Authors: Jiang Shaoning , Gavrikova Tatyana A. , Messina Joseph L.
Published: April 2014

Impaired insulin receptor (IR) activity has been found in various models of insulin resistance, including models of injury or critical illness and Type 2 diabetes. However, mechanisms that modulate IR function remain unclear. With an animal model of critical-illness diabetes, we found insulin-induced IR tyrosine phosphorylation in the liver was impaired as early as 15 min following trauma and hemorrhage. Possible mechanisms for this defect were examined, including IR protein levels and IR posttranslational modifications. The total amounts of hepatic IRα and IRβ subunits and the membrane localization of the IR were not altered by trauma and hemorrhage, and, likewise, no change in IR tyrosine nitration was found in the liver. However, there was a decrease in the level of protein O-linked β-N-acetlyglucosamine (O-GlcNac) modification on Ser/Thr in the liver following trauma and hemorrhage. Inhibition of JNK increased IR O-GlcNac modification, implicating an involvement of JNK. These findings suggest that a balance between O-GlcNac modification and JNK-induced phosphorylation may exist, with decreased Ser/Thr O-GlcNac modification following trauma and hemorrhage, allowing JNK to phosphorylate the IR on neighboring Ser/Thr residues, which subsequently inhibits IR activity. The present studies suggest potential mechanisms of hemorrhage-induced defects in IR activity and a potential role for acutely decreased O-GlcNac and increased serine phosphorylation of the IR.
Role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in Barrett's cells and Barrett's esophageal adenocarcinoma cells
Authors: Li Dan , Cao Weibiao
Published: April 2014

Mechanisms whereby acid reflux may accelerate the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. Acid and reactive oxygen species (ROS) have been reported to cause DNA damage in Barrett's cells. We have previously shown that NADPH oxidase NOX5-S is responsible for acid-induced H2O2production in Barrett's cells and in EA cells. In this study we examined the role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in a Barrett's EA cell line FLO and a Barrett's cell line CP-A. We found that pulsed acid treatment significantly increased tail moment in FLO and CP-A cells and histone H2AX phosphorylation in FLO cells. In addition, acid treatment significantly increased intracellular Ca2+in FLO cells, an increase that is blocked by Ca2+-free medium with EGTA and thapsigargin. Acid-induced increase in tail moment was significantly decreased by NADPH oxidase inhibitor diphenylene iodonium in FLO cells, and by blockade of intracellular Ca2+increase or knockdown of NOX5-S with NOX5 small-interfering RNA (siRNA) in FLO and CP-A cells. Acid-induced increase in histone H2AX phosphorylation was significantly decreased by NOX5 siRNA in FLO cells. Conversely, overexpression of NOX5-S significantly increased tail moment and histone H2AX phosphorylation in FLO cells. We conclude that pulsed acid treatment causes DNA damage via increase of intracellular calcium and activation of NOX5-S. It is possible that in BE acid reflux increases intracellular calcium, activates NOX5-S, and increases ROS production, which causes DNA damage, thereby contributing to the progression from BE to EA.
Triptolide activates unfolded protein response leading to chronic ER stress in pancreatic cancer cells
Authors: Mujumdar Nameeta , Banerjee Sulagna , Chen Zhiyu , Sangwan Veena , Chugh Rohit , Dudeja Vikas , Yamamoto Masato , Vickers Selwyn M. , Saluja Ashok K.
Published: April 2014

Pancreatic cancer is a devastating disease with a survival rate of <5%. Moreover, pancreatic cancer aggressiveness is closely related to high levels of prosurvival mediators, which can ultimately lead to rapid disease progression. One of the mechanisms that enables tumor cells to evade cellular stress and promote unhindered proliferation is the endoplasmic reticulum (ER) stress response. Disturbances in the normal functions of the ER lead to an evolutionarily conserved cell stress response, the unfolded protein response (UPR). The UPR initially compensates for damage, but it eventually triggers cell death if ER dysfunction is severe or prolonged. Triptolide, a diterpene triepoxide, has been shown to be an effective compound against pancreatic cancer. Our results show that triptolide induces the UPR by activating the PKR-like ER kinase-eukaryotic initiation factor 2α axis and the inositol-requiring enzyme 1α-X-box-binding protein 1 axis of the UPR and leads to chronic ER stress in pancreatic cancer. Our results further show that glucose-regulated protein 78 (GRP78), one of the major regulators of ER stress, is downregulated by triptolide, leading to cell death by apoptosis in MIA PaCa-2 cells and autophagy in S2-VP10 cells.
Genistein attenuates hypoxic pulmonary hypertension via enhanced nitric oxide signaling and the erythropoietin system
Authors: Kuriyama Sachiko , Morio Yoshiteru , Toba Michie , Nagaoka Tetsutaro , Takahashi Fumiyuki , Iwakami Shin-ichiro , Seyama Kuniaki , Takahashi Kazuhisa
Published: April 2014

Upregulation of the erythropoietin (EPO)/EPO receptor (EPOR) system plays a protective role against chronic hypoxia-induced pulmonary hypertension (hypoxic PH) through enhancement of endothelial nitric oxide (NO)-mediated signaling. Genistein (Gen), a phytoestrogen, is considered to ameliorate NO-mediated signaling. We hypothesized that Gen attenuates and prevents hypoxic PH. In vivo, Sprague-Dawley rats raised in a hypobaric chamber were treated with Gen (60 mkg/kg) for 21 days. Pulmonary hemodynamics and vascular remodeling were ameliorated in Gen-treated hypoxic PH rats. Gen also restored cGMP levels and phosphorylated endothelial NO synthase (p-eNOS) at Ser1177 and p-Akt at Ser473 expression in the lungs. Additionally, Gen potentiated plasma EPO concentration and EPOR-positive endothelial cell counts. In experiments with hypoxic PH rats' isolated perfused lungs, Gen caused NO- and phosphatidylinositol 3-kinase (PI3K)/Akt-dependent vasodilation that reversed abnormal vasoconstriction. In vitro, a combination of EPO and Gen increased the p-eNOS and the EPOR expression in human umbilical vein endothelial cells under a hypoxic environment. Moreover, Gen potentiated the hypoxic increase in EPO production from human hepatoma cells. We conclude that Gen may be effective for the prevention of hypoxic PH through the improvement of PI3K/Akt-dependent, NO-mediated signaling in association with enhancement of the EPO/EPOR system.