bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of CuO on the Electrochemical Activity of Li2MnO3
Authors: Arachi Yoshinori , Hinoshita Kentarou , Nakata Yoshiyuki
Published: May 2012

A new effect to induce the electrochemical activity of Li2MnO3 was found. The samples prepared by co-precipitation consisted of Li2MnO3 and CuO phases. The particle size of Li2MnO3 was much smaller than that of CuO by using TEM observation equipped with EDX. The specific charge and discharge capacity increased with the content of CuO, while maintaining the electrochemical characters of Li2MnO3. The ab-initio electronic structure calculation was carried out and the densities of states (DOS) were obtained for Cu-containing Li2MnO3 supercell and Li2MnO3. On basis of experimental and calculated results, a partial replacing Mn by Cu could improve the electrical property of Li2MnO3. A possible reason of the effect is that coexisting with CuO depressed the kinetic barrier of the electrode reaction for Li2MnO3.
Formation of Small Hole Polarons in Olivine Phosphate Cathode Materials
Authors: Johannes Michelle D. , Hoang Khang , Allen Jan L. , Gaskell Karen
Published: May 2012

We investigate polaron formation in olivine LiMnPO4, LiFePO4, LiCoPO4 and LiNiPO4 using a combination of first principles calculations and experimental XPS spectra. We determine that details of the electronic structure near the Fermi energy, relevant to localization of a hole polaron, are not accurately captured using the standard GGA+U methodology and require a hybrid functional approach. We show that polaron formation is possible in all but the Ni-based compound and discuss the possibility of an electronic instability caused by electron withdrawal during delithiation caused by oxygen evolution.
QCM Analysis of the Deposition Process in the Presence of the Additives for Copper Foil
Authors: Yoshihara Sachio
Published: May 2012

The copper film electrodeposited from the bath in the presence of some sort of additives such as brightener like Bis-(3-sulfopropyl)-disulfide (SPS) shows the decrease of Vickers hardness and tensile strength during keeping it even at room temperature. We have already reported that 2-Mercapto-5-benzimidazole (2M-5S) had the effects for preventing such a property change. In this report the incorporation processes of above additives were investigated under various electrolytic conditions by use of Quartz Crystal Microbalance (QCM) Method. The incorporation process depended on their electrolytic conditions. That is, under the electrolytic condition in the case of high concentration of all bath components and high current density and vigorous stirring of the bath, the incorporation process of the additives under linear sweep voltammetry mode was slightly different from that under the electrolytic condition in the case of low concentration of all bath components and low current density and no stirring of the bath.
A Comparative Study on the Corrosion Resistance of Cerium-Based Conversion Coatings on AZ91D and AZ31B Magnesium Alloys
Authors: Castano Carlos E. , Maddela Surender , O'Keefe Matthew J. , Wang Yar-Ming
Published: May 2012

In the present work a comparative study has been carried out on the surface morphology, electrochemical properties and corrosion performance of cerium-based conversion coatings (CeCCs) on AZ91D and AZ31B magnesium alloys. The as-deposited coatings consisted of a two layer structure: a continuous Mg/Al oxide transition layer of ~ 50 nm thick and a CeCC layer of ~ 400 nm thick. Potentiodynamic polarization and impedance spectroscopy results using a 0.6 wt% NaCl and 0.6 wt% (NH4)2SO4 electrolyte showed that cerium-based conversion coatings enhanced the corrosion resistance of AZ91D and AZ31B magnesium alloys compared to polished uncoated samples. Good correlation of electrochemical test and ASTM B117 salt spray was realized.
Effect of Hydrogen Peroxide Concentration on Corrosion Resistance of Cerium-Based Conversion Coatings on Mg AZ91D Alloy
Authors: Maddela Surender , O'Keefe Matthew J. , Wang Yar-Ming
Published: May 2012

The corrosion resistance of cerium-based conversion coatings (CeCCs) on Mg AZ91D alloy was investigated as a function of the hydrogen peroxide (H2O2) concentrations in the CeCC spray deposition solution. The corrosion performance of the coated panels was evaluated by ASTM B117 neutral salt spray testing and electrochemical analysis. Coating morphology and thickness were characterized by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES), respectively. All of the panels coated with H2O2 in the solution had better corrosion resistance than the 0 vol.% H2O2 in solution. Magnesium alloy panels coated with 4 and 8 vol.% of H2O2 concentrations in the spray solution performed the best in salt spray tests. Mg AZ91D alloy panels coated with 4 vol.% H2O2 had the highest impedance (12,000 Ohm.cm2), while 0 vol.% peroxide had the lowest impedance (3000 Ohm.cm2), in agreement with salt spray performance.
Model of Carbon Utilization in a Solid Carbon Fuel Cell
Authors: Alexander Brentan R. , Mitchell Reginald E. , Gür Turgut M.
Published: May 2012

The carbon fuel cell, a novel electrochemical conversion scheme for the production of efficient electric power from solid carbonaceous fuels, is investigated. A model of the carbon fuel cell is developed and validated, and a new definition for overall cell efficiency, which accounts for the partial utilization of the solid fuel, is proposed. Results indicate that the modeled cell geometry can operate in an optimal regime offering efficiencies near 60% and cell power densities of 100 mW/cm2 on a fuel bed height of 5 mm.
Power Generation Characteristics of Pulse Jet Rechargeable Direct Carbon Fuel Cells at Different Isooctane Fuel Supply Frequency
Authors: Yabuki Akinori , Ohba Fuhito , Shimada Hiroyuki , Tanaka Hiroki , Sakamoto Shuhei , Ihara Manabu
Published: May 2012

Power generation tests of pulse jet (PJ) rechargeable direct carbon fuel cells (PJ-RDCFCs), which supply small amounts of isooctane to the anode by pulse jetting, were conducted at different PJ supply frequency and for different PJ supply amount. PJ-RDCFCs could control power density by controlling the supply frequency. At 1 pulse/sec, power generation characteristics of PJ-RDCFCs approached flow-type. At lower supply frequency, power generation characteristics approached batch-type and fuel utilization becomes higher. Fuel utilization also became higher with decreasing PJ supply amount. In the reaction mechanism of a PJ-RDCFC, the contributing species for power generation might be hydrogen, carbon monoxide and hydrocarbons when the PJ supply frequency is high (≈1 pulse/sec). With decreasing supply frequency, carbon which has lower reactivity became to contribute to the power generation. In conclusion, the electrochemical reactions in the anode side in a PJ-RDCFC can be controlled by adjusting the pulse jet supply frequency.
Hydrogen and Electricity from Carbon in a Coupled Steam-Carbon-Air Fuel Cell
Authors: Alexander Brentan R. , Mitchell Reginald E. , Gür Turgut M.
Published: May 2012

A novel hybrid electrochemical conversion scheme for the spontaneous and simultaneous production of carbon-free hydrogen and electric power is proposed and modeled. The design combines a carbon fuel cell and a steam-carbon fuel cell into a steam-carbon-air fuel cell that shares a single solid carbonaceous fuel bed in the anode chamber. A model of the combined cell is developed and a new definition for overall cell efficiency, which accounts for the hydrogen product generated, is produced. Results indicate that the proposed cell can reach efficiencies above 76%, and can also realize a nine-fold increase in hydrogen production rate density compared to a steam-carbon fuel cell with only a doubling of the cell active area.
Chemical Degradation Behavior of SOFC Anode Due to Trace Impurities Contained in a Coal Derived Syngas
Authors: Kuramoto Koji , Fukushima Toshiyo , Matsuoka Koichi , Suzuki Yoshizo , Kishimoto Haruo , Yamaji Katsuhiko , Horita Teruhisa , Brito Manuel E. , Yokokawa Harumi
Published: May 2012

In an effort to explore the feasibility of coal-syngas use as a fuel for solid oxide fuel cell (SOFC), we need to clarify the anode degradation behavior due to the interaction between trace chemical impurities and SOFC anode and electrolyte. We conducted the power generation tests using electrolyte-supported button cells with Ni-YSZ anode fueled by the simulated coal syngas with/without doping of selected gaseous/condensable contaminants. Doping of metal vapors volatilized from coal ash to fuel gas resulted in the formation of eutectic melting or agglomeration of Ni over the anode layer. When Na vapor was injected to the anode chamber, solid state Na-Si deposit was observed on the anode surface which would cause the increase in resistance for fuel supply. No significant negative influence was seen in the variation of current density with time as well as AC impedance in the case of injection of 2ppm halide components. (HCl & HF)
(Invited) Determination of Efficiency in Direct Carbon Fuel Cells
Authors: Cooper John F. , Selman J. R.
Published: May 2012

Expressions for total efficiency of a carbon fuel cell reduce to a simple product of voltage efficiency (V(i)/V°) and carbon efficiency (defined as n/4, where n is the number of equivalents of charge associated with reaction of one mole of carbon). Examination of steady state polarization curves led us to propose that separate reactions predominate in two distinct regions of the curve: there is a low potential segment in which rate is proportional to total pore area, and a high potential segment where rate is a function of external flow conditions but not internal area. We make use of the Yongdan Li model for 4-electron net anodic oxidation of carbon to interpret the shift between the two segments as accompanied by shift in location of the reaction from the interior pores to the external surface of the anode, where n = 4. Total efficiency may be maximized using anodes fabricated from atomically disordered carbon by confining current to the exterior surface by means of filling the pores with inert material.
CaWO4 : Eu3+, Dy3+, Tb3+ Phosphor Crystals for Solid-State Lighting Applications
Authors: Khanna Aloka , Dutta Partha S.
Published: May 2012

Calcium tungstate (CaWO4) phosphor crystals doped with Ln3+ (Ln = Eu, Dy, Tb) were grown from high temperature solutions (NaWO4 flux) and their properties compared with powders synthesized using traditional solid-state reaction technique. The flux-grown crystals exhibited enhanced excitation and emission intensities as compared to the powders. An optimized flux to solute ratio of 2:1 at growth temperatures in the 1100-1200 °C range results in the largest size optically clear crystals.
The Effect of Chloride on Passive Oxide Film Breakdown on Stainless Steels and Aluminum
Authors: Natishan Paul M. , O'Grady William E. , Martin Farrel J. , Rayne Roy J. , Kahn Hal , Heuer Arthur H.
Published: May 2012

The evidence for adsorption or incorporation of chloride ions (Cl-) in the passive oxide film on stainless steels and Fe-Cr alloys appears to be contradictory, with some investigators reporting Cl- in the oxide and others reporting its absence. We consider this issue by determining Cl- adsorption and/or incorporation as a function of potential (below the pitting potential) on 316L stainless steel using X-ray photoelectron spectroscopy and compare our results to the literature on uptake of Cl- by stainless steels and to studies on uptake of Cl- on aluminum. The important finding is that no Cl- is observed in the oxide film on 316L stainless steel whereas in the case of aluminum, Cl- is incorporated into the oxide film. We present the case for those instances where Cl- is observed in the oxide films on stainless steels and Fe-Cr alloys, these observations are a result of the experimental procedures employed.
Formation of Nickel Nanowires by Electroless Deposition
Authors: Kawamori Makoto , Yagi Shunsuke , Matsubara Eiichiro
Published: May 2012

The formation of nickel nanowires by electroless deposition was electrochemically investigated by an in-situ quartz crystal microbalance measurement combined with an in-situ mixed potential measurement. These electrochemical measurements revealed that the control of a terminal point of the nickel deposition reaction is critical for the formation of nanowires. The terminal point has been controlled by adjusting a concentration of sodium hydroxide and trisodium citrate. Based on the formation mechanism of nanowires, nickel nanowires 100-370 nm in diameter with several dozen μm of length were successfully prepared by controlling the terminal point and the nucleation rate.
Preparation of Silver Nanoparticles-Nafion Membrane Composite by Photoreduction Process
Authors: Hasegawa Takashi , Strunskus Thomas , Zaporotjenko Vladimir , Faupel Franz , Mizuhata Minoru
Published: May 2012

Preparation method of silver nanoparticles (AgNPs) dispersed in Nafion 115 membrane using UV photoreduction process was established. The loading amount of AgNPs was controlled with UV irradiation time. AgNPs might exist in ionic cluster channel in Nafion membrane stably without any stabilizing reagent. The particle size was measured by transmission electron microscope (TEM). The mean particle size was ca. 13 nm in diameter. The obtained nanocomposite membrane has absorption bands due to local surface plasmon resonance (LSPR) at around 400 nm. The band position depends on the refractive index of suspension as expected by Mie theory. Furthermore very little amount of solvent affected the LSPR bands sensitively due to changing the highly localized refractive index.
Microfluidic Human Blood Plasma Separation for Lab on Chip Based Heavy Metal Detections
Authors: Zhong Ruizhi , Wu Nianqiang , Liu Yuxin
Published: May 2012

Environmental and occupational exposure to heavy metals is an emerging health concern. Microfluidic based biosensor technologies are expecting to provide inexpensive, field-deployable tools for rapid, on-site detection of heavy metals. Accurate, fast, and affordable analysis of blood components is the prime interest for biosensor applications in medicine research. Plasma separation is important for specific downstream detection of heavy metals from patient bloods, such as preventing contamination of the plasma with blood cells' DNA and hemoglobin. We have developed a microfluidic device for separating the plasma from the whole human blood. In addition, we demonstrated polydimethylsiloxane (PDMS) on-chip microvalves for lab on chip (LOC) integration potentially for multiplex heavy metal detections.
Influence of Polyethylene Glycol on the Morphology of Electrodeposited ZnO Films for Dye-Sensitized Solar Cells
Authors: Lizama Tzec Francisco I. , Oskam Gerko
Published: May 2012

Polyethylene glycol (PEG) was used as an additive for the electrodeposition of ZnO films from Zn(NO3)2. The presence of PEG in the bath resulted in a more open morphology and an increase of the active surface area of the ZnO films, and thermogravimetric analysis showed that a small amount of PEG was incorporated in the films. As a consequence of the improved film morphology, dye-sensitized solar cells prepared with galvanostatically deposited ZO films showed a higher conversion efficiency.
Synthesis of Vertically Aligned Gold Nanowire-Ferromagnetic Metal Matrix Composites
Authors: Chi SuChih , Farias Stephen L. , Cammarata Robert C.
Published: May 2012

We report on the synthesis of thin films composed of vertically-aligned gold nanowire arrays in ferromagnetic matrices (nickel and iron). This process involves electrodepositing the Au nanowire arrays usng commercially available anodic aluminum oxide (AAO) nanoporous membranes. After dissolving the templates, the ferromagnetic matrices are grown around the nanowires to produce the two-phase nanocomposites. A discussion of this processing technique and microstructural characterization of the thin film nanocomposites will be presented.
Charge Compensated (Al, N) Co-Doped Zinc Oxide (ZnO) Films for Photoelectrochemical Application
Authors: Shet Sudhakar
Published: May 2012

ZnO thin films with significantly reduced bandgaps were synthesized by doping N and co-doping Al and N at 100oC. All the films were synthesized by radio-frequency magnetron sputtering on F-doped tin-oxide-coated glass. We found that co-doped ZnO:(Al,N) thin films exhibited significantly enhanced crystallinity as compared to ZnO doped solely with N, ZnO:N, at the same growth conditions. Furthermore, annealed ZnO:(Al,N) thin films exhibited enhanced N incorporation over ZnO:N films. As a result, ZnO:(Al,N) films exhibited improved photocurrents than ZnO:N films grown with pure N doping, suggesting that charge-compensated donor-acceptor co-doping could be a potential method for bandgap reduction of wide-bandgap oxide materials to improve their photoelectrochemical performance.
Hematite (α-Fe2O3) Photoanodes for the Photooxidation of Water
Authors: Herrmann-Geppert Iris , Bogdanoff Peter , Hepperle Linda , Fiechter Sebastian
Published: May 2012

Nanostructured hematite films prepared by a sol-gel procedure were evaluated for the photo-induced oxygen evolution reaction (OER). Surface treatments such as plasma and post-annealing at 500 °C in oxygen gas flow were used in order to condition the electrode surface. Electrochemical measurements of the plasma treated samples revealed that the surface was reorganized in terms of enhanced catalytic properties and reduced recombination centers at the surface. Photocurrents in the milli-Ampere range were yielded at 0.92 V(NHE) in 1 M KOH. In contrast to the plasma samples, the post-annealing samples displayed higher bulk crystallinity resulting in a more enhanced photovoltage. XRD and TEM analysis confirmed the texturing of a beneficial highly oriented hematite film (110) parallel to the back contact. Nevertheless, lower photocurrents for this post-annealed sample compared to the plasma one indicated that the catalytic centers were not fully recovered at the surface.
Microbial Tango with Shewanella Oneidensis: Design Elements and Application of a Novel Renewable Energy Source Using Wastewater Containing Organic Compounds
Authors: Braustein Harold E.
Published: May 2012

Microbial fuel cells (MFC) harvest the catabolic energy of microbial colonies and communities. For many years I been tested and improved various designs to create usable technology for real world applications with maximum efficiency and economic viability. A variety of microbes are being tested for peak performance in terms of metabolism, growth, and reductive potential, and mediator-less function. MFCs are in the early stages of application with numerous goals for future research on the horizon. We produce electricity also, directly from degradation of organic matter - wastewater-containing phenols-in a microbial fuel cell (MFC). Like any fuel cell, a MFC has an anode chamber and a cathode chamber. The anaerobic anode chamber is most commonly connected internally to the cathode chamber by an ion exchange membrane, and an external wire that completes the circuit. Microbial fuel cells use wastewater as a fuel, or more generally a dilute solution of a variety of organic materials in water (like phenols and poly phenols).
Hydrogen and Fuel Cell Technology Demonstrations in Developing Countries: Turkey Example
Authors: Yazici M. Suha , Lymberopoulos Nikos , Hatipoglu Mustafa
Published: May 2012

The International Center for Hydrogen Energy Technologies (ICHET) has been implementing measures to demonstrate potential benefits of "hydrogen and fuel cell systems" in developing countries. To achieve its mission, ICHET implements pilot demonstration projects, provides applied research and development funding, and organizes workshops, education and training activities together with industry for early adaptation. Project results from various demonstrations including fuel cell forklift, fuel cell based Uninterrupted Power Supply (UPS), an island project, and renewable energy systems integrated mobile house will be covered below.
Eutectic Mixtures of Ionic Liquids Electrolytes for Electric Double Layer Capacitors
Authors: Higashiya Seiichiro , Devarajan Thamarai Selvi , Rane-Fondacaro Manisha V. , Haldar Pradeep
Published: May 2012

Eutectic mixtures of oxygen-containing spirobipyrrolidinium-based room temperature ionic liquids (RTIL) were applied as electrolytes for electric double layer capacitors (EDLC). The mixtures of RTILs exhibit lower melting points with conductivity, and viscosity comparable with 2MOP BF4. The potential window of mixed RTIL was about 5.5 V (at 50 μA/cm2 threshold). The RTIL mixtures exhibit higher breakdown potential (> 4.6 V) as compared to conventional molecular solvent (acetonitrile)-based cells (~4.0 V) in EDLC tests. However, these RTIL mixtures lead to higher equivalent series resistance (ESR) initiating around 3.9 V and lower capacitance. Cycling of the negative electrode at 4.6 V led to degradation of the active carbon material, while the positive electrode maintained its integrity.
Evaluation of Anode Electrode Materials for Cu-Cl/HCl Electrolyzers for Hydrogen Production
Authors: Ranganathan Santhanam , Edge Patrick S. , Easton E. Bradley
Published: May 2012

Ceramic carbon electrodes (CCE) containing poly aminopropyl siloxane (PAPS) were fabricated by the sol-gel method. These CCEs have previously been shown to exhibit high performance towards the anode reaction of the electrolytic process used in the Cu-Cl thermochemical cycle for hydrogen production, with optimal performance being achieved at 36 wt% PAPS. Using cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy, the peak performance at 36 wt% PAPS was explained in terms of the optimization of carbon surface area, anionic transport and electronic conductivity. In addition, we also demonstrated the electrolysis performance in the full cell.
Analysis of the Ionic Conduction Behavior in Some Room Temperature Molten Fluorides
Authors: Inoue Hidemi , Isogai Tomohiro , Nakai Takaaki , Saito Morihiro , Inaba Minoru , Tasaka Akimasa
Published: May 2012

The self-diffusion coefficients of cations and anions increased with increasing the HF-concentration and temperature in (CH3)3N·mHF and (CH3)4NF·mHF melts. Behavior of the self-diffusion coefficients of cation and anion in every melt is good agreement with an increase in ionic conductivity and a decrease in viscosity (1). The transference number of (FH)nF- anions estimated from the values of self-diffusion coefficients for each ion in every melt was almost constant and their values were around 0.6 and 0.7 in the (CH3)3N·mHF and the (CH3)4NF·mHF melts, respectively. Therefore, it is concluded that the diffusion of (FH)nF- anions is faster than that of each cation in these melts.
The Influence of Charge Distribution on Ion Diffusion in Molten Salts: A Model Study
Authors: Li Hualin , Kobrak Mark N.
Published: May 2012

Ionic liquids have seen increasing use as electrolytes in devices, but the relationship between their chemical structure and their transport properties remains unclear. We report the results of molecular dynamics simulations on a series of model molten salts that differ from each other only in their charge distribution. The observed variation of ion transport properties with temperature indicates that the distribution of charge affects the energy required for activated hopping in ionic liquids. This is an important principle for the design of task-specific ionic liquids.
Voltammetric Investigations of the Fries Rearrangement in an Ionic Liquid
Authors: Cheek Graham T.
Published: May 2012

The electrochemical behavior of phenyl benzoate (PB) in the neutral AlCl3 : 1-ethyl-3-methylimidazolium chloride ionic liquid has been studied. Addition of HfCl4 to phenyl benzoate in this medium produces a positive potential shift for the phenyl benzoate reduction process. Heating the solution to 80oC for 30 hours gives 4-hydroxybenzophenone as the major product. Cyclic voltammetric studies show that HfCl4 reacts with the ionic liquid to produce relatively small amounts of Al2Cl7-, so that HfCl4 is still the principal Lewis acid in this system. Comparison studies using added AlCl3 in place of HfCl4 show similar behavior, with a somewhat different potential shift for the AlCl3 : PB interaction.
Fabrication of Composite Nanoporous Si Films with Gold Nanoparticles to Enhance the Efficiency of Silicon Solar Cells
Authors: Hachimura Hironori , Nam Kwanwoo , Tanaka Yuki , Ihara Manabu
Published: May 2012

When metal nanoparticles are irradiated by light, their surface plasmons are excited (called localized surface plasmon effect) and the incident light is both scattered and absorbed. When this effect is applied to silicon (Si) solar cells, performance is expected to improve due to the scattering effect and the electromagnetic field enhancement effect. In this study, to more effectively apply the surface plasmon effect (both the scattering effect and electromagnetic field enhancement effect) to Si solar cells, we introduced metal nanoparticles into the pores of porous Si and brought metal nanoparticles and Si in closer contact. We successfully fabricated composite nanoporous Si films with gold nanoparticles (AuNP) by introducing 15- to 20-nm-diameter AuNP into 20- to 30-nm-diameter pores of porous Si. The reflectance of the films decreased over the entire wavelength range due to electrochemical etching and decreased even further at 800-2000 nm wavelength due to introduction of AuNP.
Single Diallylamine Type Copolymer Additive which Perfectly Fills Cu Electrodeposition with only 1ppm
Authors: Takeuchi Minoru , Kondo Kazuo , Kuri Hideyuki , Bunya Masaru , Okamoto Naoki , Saito Takeyasu
Published: May 2012

Cu via-filling is an essential technology for fabricating signal lines both on chips and on printed circuit boards and also through silicon via in 3-D wafer lever packaging for electrical devices. Generally, four additives, such as suppressors, accelerators, levelers and chloride ions, are added to a Cu electrodeposition bath in order to achieve bottom-up filling. The selection of additives and the control of additive concentrations are complicated and cause cost increase and complicated quality control. In order to solve these problems, we succeeded in developing bottom-up filling by only one additive, which has four kinds of functions. This additive is a diallylmethylamine copolymer, and it has cationic nitrogen and chloride ions and sulfur dioxide in its structure. The counter ion of diallylmethylamine copolymer was chloride ion and bromide ion. They were synthesized from the monomer with anions in aqueous solution from radical polymerization. Surface morphology and cross section of electrodeposits were observed by scanning electron microscopy (SEM) and optical microscopy (OM). Linear sweep voltammetry (LSV) and quarts crystal microbalance (QCM) were conducted.
(Invited) Processing and Integration Considerations for Successful Copper Electrodeposition in 3D IC Applications
Authors: Papanu J. S. , Cogorno M. , Erickson D.
Published: May 2012

The impact of upstream integration and plating process conditions on the electrochemical filling of through-silicon vias (TSV) was investigated. For the same plating process, persistent bottom voiding was eliminated by tuning of the etch process. Thermal desorption mass spectrometry analysis showed the presence of chemical residues consistent with post-etch cleaning chemistry. The coverage of barrier and seed layers deposited by physical vapor deposition was investigated with TEM analysis, and found to be marginal in the vicinity of the bottom of high aspect ratio vias. From the plating side, the process was partitioned and tuned for bottom and top filling. Partial-fill studies were beneficial to identify the onset of bottom up fill for isolated and dense vias. By combining optimized upstream processing and plating process approaches with Generation 3 additive chemistry, bottom up fill was demonstrated for high aspect ratio features > 100 um deep. Finally, significant throughput improvement was shown by tuning the current-density-versus-time profile of the established baseline process.
Fluoroethylene Carbonate as an Electrolyte Additive for Improving the Performance of Mesocarbon Microbead Electrode
Authors: Wang Zhou-Cheng , Xu Jie , Yao Wan-Hao , Yao Yi-Wen , Yang Yong
Published: May 2012

Fluoroethylene carbonate (FEC) was used as a kind of film-forming electrolyte additive for lithium-ion battery. The cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) were used to study the influence of FEC additive on the electrochemical properties of mesocarbon microbead (MCMB)/Li cell. The results show that a thin, low-resistive and uniform SEI film was formed on the surface of MCMB electrode, which cause the excellent cyclability of the electrode.
A Study of Cobalt and Manganese Fluorides as Cathode Materials for Rechargeable Lithium Cells
Authors: Behl Wishvender K. , Read Jeffrey A.
Published: May 2012

This paper describes a study of the lithium/transition metal fluoride cells using nanocomposites of carbon with cobalt or manganese fluorides as cathode materials. The nanocomposite cathode materials were prepared by high energy milling of carbon and metal fluorides. It was, however, found that cobalt trifluoride reacted with carbon during the high energy milling process to form carbon fluoride. The Li/cobalt fluoride cells were, therefore, studied by using nanocomposite cathodes prepared by high energy milling of carbon, cobalt metal and lithium fluoride or cathodes prepared by mixing carbon and cobalt trifluoride without subjecting the mixture to the high energy milling process. The charge- discharge characteristics of lithium/transition metal fluoride cells were studied at 22oC and 50oC using a 1M LiPF6-sulfolane solution as the electrolyte. The cells were found to be electrochemically reversible but could not be completely charged due to simultaneous oxidation of the electrolyte at potentials above ~4.5 Volts.
Effects of Doping and C60 Coating on the Electrochemical Characteristics of Silicon Film Anodes for Lithium Secondary Batteries
Authors: Arie Arenst Andreas , Lee Joong Kee
Published: May 2012

Effects of B or P doping and Fullerene C60 film coating on the anodic characteristics of Si film are studied by electrochemical measurements such as charge-discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. Results show that the P doped Si (n-type) anodes coated by fullerene film coating exhibit a more enhanced cycle performance and smaller charge transfer resistance compared with those of intrinsic and B doped Si coated by fullerene film. The C60 coated n-type Si electrodes demonstrate a high discharge capacity above 3,000 mAhg-1 after 100th cycle under 0,3 C rate. The more enhanced electrochemical characteristics are attributed to the improvements of electronic conductivity of Si film by P doping and the suppression of side reactions with the electrolyte by the fullerene film coating.
Deflagration Synthesis of Nanocrystalline LiNi1/3Co1/3Mn1/3O2 Cathode Material
Authors: Li Jiebin , Xu Youlong , Du Xianfeng , Xiong Lilong
Published: May 2012

The homogenous precursor has been prepared using a mixed aqueous solution of Ni(NO3)2•6H2O, Co(NO3)2•6H2O, Mn(NO3)2 and LiNO3 as metal sources and citric acid as chelating agent and fuel. The nanocrystalline LiNi1/3Co1/3Mn1/3O2 powder was rapidly synthesized by deflagrating the dried precursor in oxygen. The as-synthesized LiNi1/3Co1/3Mn1/3O2 powder has a rhombohedral crystal system with an impurity phase of Li2MnO3. The mean crystallite size of as-synthesized powder was 40.89 nm. The annealed LiNi1/3Co1/3Mn1/3O2 powder was mainly consisted of particle agglomerates with the primary particles size of 100-300 nm. The high initial capacities of 208.0 mAh•g-1 (2.8-4.6 V) and 173.6 mAh•g-1 (2.8-4.3 V) were discharged at the rate of 0.05 C, respectively. Its capacity retentions were 89.3% and 93.4% within the voltage range of 2.8-4.6 V and 2.8-4.3 V at 0.1 C after 20 cycles, respectively. The results suggest that the deflagration synthesis holds potential to rapidly prepare nanocrystalline LiNi1/3Co1/3Mn1/3O2 cathode material.
Mixed Metal Oxide Catalysts for Rechargeable Lithium-Air Batteries
Authors: Anandan Venkataramani , Kudla Robert , Drews Andy , Adams Jim , Karulkar Mohan
Published: May 2012

In this report, the preparation, characterization and electrochemical performance of manganese and cobalt containing mixed metal-oxide catalysts for use in lithium-air cells was investigated. Samples with several manganese/cobalt ratios were prepared by a combustion synthesis method and mixed with a high surface-area carbon to form cathodes. All catalysts resulted in a reduction in charge overpotential with respect to a carbon cathode, but the relative performance of the catalysts may depend on the discharge product. To ensure a fair comparison of the materials, catalysts were further evaluated for the charge overpotential to decompose Li2O2. In this test, all the catalysts exhibited a similar recharge potential of about 3.85V at a current density of 0.05mA/cm2 which is ~150mV lower than a plain carbon electrode. Varying the Mn to Co ratio did not have a significant effect on the charge overpotential for the pre-loaded electrodes at lower current density, suggesting that the catalyst efficiency is not a limiting factor in this system.
A Study on the Mechanism of Electrodeposition of Ni/SiC Composite Coatings using Impedance Technique
Authors: Sohrabi Abouzar , Dolati Abolghasem
Published: May 2012

Ni/SiC nanocomposite coatings were electrodeposited using Watts type bath and different SiC particle size. The electrodeposition behavior of Ni/SiC nanoelectrocomposites was studied using electrochemical techniques such as impedance spectroscopy (EIS) and voltammetry. In this study it was shown that SiC particles modify the EIS diagram and voltammograms as well as surface morphology of electrodeposited layers. Experimental results showed that SiC particles not only affect the formation of intermediate species and decrease charge transfer resistance but also increase the nucleation sites for nickel electrodeposition and thus affect the microstructure of electrodeposited Ni/SiC nanocomposites. Furthermore, SiC particles promote further adsorption/desorption of intermediates of nickel on the electrode surface, as shown by impedance studies.
Properties of Pulse Electrodeposited CuInSe2 Films
Authors: Shanmugavel Shanmugavel , Srinivas Srinivasan , Murali K. R.
Published: May 2012

Copper Indium Selenide films were deposited by the pulse plating technique at different bath temperatures in the range of 30°C - 80°C and at 50 % duty cycle (15s ON and 15s OFF). X-ray diffraction studies indicated the formation of single phase chalcopyrite copper indium selenide films. X-ray photoelectron spectroscopic studies indicated core levels of Cu 2p, In 3d and Se 3d. Atomic force microscope studies indicated that the surface roughness and grain size increased with duty cycle. The band gap of the films was in the range of 0.9 to 1.0 eV. The refractive index (n) and extinction co-efficient (k). values were determined from the transmission data. The n and k values are in the ranges of 2.68-1.78 and 0.43-0.083, respectively.
Pulse Electrodeposited CuGaSe2 Films and Their Properties
Authors: Chitra Chitra , Sampathkumar Vasantha , Murali K. R.
Published: May 2012

Copper gallium selenide films were deposited for the first time by the pulse electrodeposition technique at different duty cycles in the range of 6 - 50 % at room temperature and at a constant current density of 5 mA cm-2. The films exhibited single phase Copper gallium selenide. Optical band gap of the films varied in the range of 1.68 eV. Surface morphology of the films indicated an increase of grain size from 25 nm to 40 nm with increase of duty cycle. A single Photoluminescence peak was observed at 1.64 eV.
Electrodeposition of Hierarchical Nanostructured Gold Coatings as Facile Route for Fabrication of Superhydrophobic Surfaces
Authors: Magagnin Luca , Menghua Wu , Torabi Tabatabaei Sara , Demir Bahriye , Sansotera Maurizio , Talaeemashhadi Sadaf , Navarrini Walter
Published: May 2012

Herein electrochemical approaches for fabrication of hierarchical nanostructured gold coatings (HNGCs) are presented. Examples of HNGCs obtained by electrodeposition in sulphite based electrolyte on nickel electroplated copper (Ni/Cu) substrates are reported. The morphology and microstructure of the nanostructured surface were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD). The effects of the electrodeposition current density (J) and deposition time on the morphological features of nanostructured gold coating will be discussed. The surface wettability on thiols treated gold surface as a function of the electrodeposition current density is investigated. Thiols treated electrodepsited HNGCs can possess superhydrophobic behavior with water contact angle of 179 °.
Human intestinal epithelial cell line SK-CO15 is a new model system to study Na+/H+exchanger 3
Authors: Yoo Byong Kwon , Yanda Murali Krishna , No Yi Ran , Yun C. Chris
Published: May 2012

The Caco-2 cell line represents absorptive polarized intestinal epithelial cells that express multiple forms of Na+/H+exchanger (NHE) in their plasma membranes. Caco-2 cells express the major apical NHE isoform NHE3, but low NHE3 expression together with inefficient transfection often hamper intended studies. In this study, we examined whether SK-CO15 cells could be used to study NHE3 regulation. SK-CO15 cells grown on Transwell inserts developed polarized epithelial cells with microvilli. The transfection efficiency of SK-CO15 cells was markedly higher compared with Caco-2 cells, an advantage in gene transfer and knockout. SK-CO15 cells expressed NHE1, NHE2, and NHE3. NHE3 expression was significantly greater in these cells than Caco-2, and NHE3 comprised more than half of total NHE activity. Apical expression of NHE3 in SK-CO15 cells was confirmed by confocal immunofluorescence and surface biotinylation. NHE regulatory factors NHERF1 and NHERF2, which are important for regulation of NHE3 activity, were expressed in these cells. Stimulatory response of NHE3 in SK-CO15 cells was assessed by dexamethasone and lysophosphatidic acid (LPA). Treatment with dexamethasone for 24–48 h increased NHE3 expression and activity. Similarly to Caco-2 cells, SK-CO15 cells lacked the expression of the LPA receptor LPA5,but exogenous expression of LPA5resulted in acute stimulation of NHE3. Forskolin acutely inhibited NHE3 activity in SK-CO15 cells, further attesting the validity of these cells. We conclude that SK-CO15 cells with the amenity for transfection and high endogenous NHE3 expression are a new and better cell model for NHE3 regulatory investigation than widely used Caco-2 cells.
Effects of cardiac preload reduction and dobutamine on hepatosplanchnic blood flow regulation in porcine endotoxemia
Authors: Jakob Stephan M. , Bracht Hendrik , Porta Francesca , Balsiger Bruno M. , Brander Lukas , Knuesel Rafael , Feng Hong-Qiang , Kolarova Anna , Ma Yingmin , Takala Jukka
Published: May 2012

Insufficient cardiac preload and impaired contractility are frequent in early sepsis. We explored the effects of acute cardiac preload reduction and dobutamine on hepatic arterial (Qha) and portal venous (Qpv) blood flows during endotoxin infusion. We hypothesized that the hepatic arterial buffer response (HABR) is absent during preload reduction and reduced by dobutamine. In anesthetized pigs, endotoxin or vehicle ( n = 12, each) was randomly infused for 18 h. HABR was tested sequentially by constricting superior mesenteric artery (SMA) or inferior vena cava (IVC). Afterward, dobutamine at 2.5, 5.0, and 10.0 μg/kg per minute or another vehicle ( n = 6, each) was randomly administered in endotoxemic and control animals, and SMA was constricted during each dose. Systemic (cardiac output, thermodilution) and carotid, splanchnic, and renal blood flows (ultrasound Doppler) and blood pressures were measured before and during administration of each dobutamine dose. HABR was expressed as hepatic arterial pressure/flow ratio. Compared with controls, 18 h of endotoxin infusion was associated with decreased mean arterial blood pressure [49 ± 11 mmHg vs. 58 ± 8 mmHg (mean ± SD); P = 0.034], decreased renal blood flow, metabolic acidosis, and impaired HABR during SMA constriction [0.32 (0.18–1.32) mmHg/ml vs. 0.22 (0.08–0.60) mmHg/ml; P = 0.043]. IVC constriction resulted in decreased Qpv in both groups; whereas Qha remained unchanged in controls, it decreased after 18 h of endotoxemia ( P = 0.031; constriction-time-group interaction). One control and four endotoxemic animals died during the subsequent 6 h. The maximal increase of cardiac output during dobutamine infusion was 47% (22–134%) in controls vs. 53% (37–85%) in endotoxemic animals. The maximal Qpv increase was significant only in controls [24% (12–47%) of baseline ( P = 0.043) vs. 17% (−7–32%) in endotoxemia ( P = 0.109)]. Dobutamine influenced neither Qha nor HABR. Our data suggest that acute cardiac preload reduction is associated with preferential hepatic arterial perfusion initially but not after established endotoxemia. Dobutamine had no effect on the HABR.
Changes in insulin sensitivity precede changes in body composition during 14 days of step reduction combined with overfeeding in healthy young men
Authors: Knudsen Sine Haugaard , Hansen Louise Seier , Pedersen Maria , Dejgaard Thomas , Hansen Jakob , Hall Gerrit Van , Thomsen Carsten , Solomon Thomas P. J. , Pedersen Bente Klarlund , Krogh-Madsen Rikke
Published: May 2012

A lifestyle characterized by inactivity and a high-calorie diet is a known risk factor for impaired insulin sensitivity and development of Type 2 diabetes mellitus. To investigate possible links, nine young healthy men (24 ± 3 yr; body mass index of 21.6 ± 2.5 kg/m2) completed 14 days of step reduction (10,000 to 1,500 steps/day) and overfeeding (+50% kcal). Body composition (dual X-ray absorptiometry, MRI), aerobic fitness (maximal O2 consumption), systemic inflammation and insulin sensitivity [oral glucose tolerance test (OGTT), hyperinsulinemic euglycemic clamp] were assessed before ( day 0), during ( days 3 and 7), and immediately after the intervention ( day 14), with follow-up tests ( day 30). Body weight had increased at days 7 and 14 ( P < 0.05). The amount of visceral fat had increased at day 14 compared with day 0 ( P < 0.05). The insulin response to the OGTT had increased at days 7 and 14 ( P < 0.05). Insulin sensitivity, estimated using the Matsuda index, had decreased at days 3 and 7 ( P < 0.01). At day 14, glucose infusion rates had decreased by ∼44% during the euglycemic clamps ( P < 0.05). Also, plasma levels of leptin and adiponectin had increased ( P < 0.05), whereas no changes were seen in inflammatory markers. At day 30, body weight and whole body adiposity were still elevated compared with day 0 ( P < 0.05), whereas the insulin sensitivity as well as the insulin response to the OGTT did not differ from baseline. The glucose response to the OGTT was only affected at day 30, with a decrease compared with day 0. Our data show that insulin sensitivity was impaired after 3 days of inactivity and overfeeding. Impairments in insulin sensitivity occurred before changes in body composition, supporting the notion that the initial steps in impairment of insulin sensitivity may be linked directly to the effects of inactivity and a high calorie intake.
Histone Lysine Methyltransferase SETD8 Promotes Carcinogenesis by Deregulating PCNA Expression
Authors: Takawa Masashi , Cho Hyun-Soo , Hayami Shinya , Toyokawa Gouji , Kogure Masaharu , Yamane Yuka , Iwai Yukiko , Maejima Kazuhiro , Ueda Koji , Masuda Akiko , Dohmae Naoshi , Field Helen I. , Tsunoda Tatsuhiko , Kobayashi Takaaki , Akasu Takayuki , Sugiyama Masanori , Ohnuma Shin-ichi , Atomi Yutaka , Ponder Bruce A.J. , Nakamura Yusuke , Hamamoto Ryuji
Published: May 2012

Although the physiologic significance of lysine methylation of histones is well known, whether lysine methylation plays a role in the regulation of nonhistone proteins has not yet been examined. The histone lysine methyltransferase SETD8 is overexpressed in various types of cancer and seems to play a crucial role in S-phase progression. Here, we show that SETD8 regulates the function of proliferating cell nuclear antigen (PCNA) protein through lysine methylation. We found that SETD8 methylated PCNA on lysine 248, and either depletion of SETD8 or substitution of lysine 248 destabilized PCNA expression. Mechanistically, lysine methylation significantly enhanced the interaction between PCNA and the flap endonuclease FEN1. Loss of PCNA methylation retarded the maturation of Okazaki fragments, slowed DNA replication, and induced DNA damage, and cells expressing a methylation-inactive PCNA mutant were more susceptible to DNA damage. An increase of methylated PCNA was found in cancer cells, and the expression levels of SETD8 and PCNA were correlated in cancer tissue samples. Together, our findings reveal a function for lysine methylation on a nonhistone protein and suggest that aberrant lysine methylation of PCNA may play a role in human carcinogenesis. Cancer Res; 72(13); 3217–27. ©2012 AACR.
The Association of PI3 Kinase Signaling and Chemoresistance in Advanced Ovarian Cancer
Authors: Carden Craig P. , Stewart Adam , Thavasu Parames , Kipps Emma , Pope Lorna , Crespo Mateus , Miranda Susana , Attard Gerhardt , Garrett Michelle D. , Clarke Paul A. , Workman Paul , de Bono Johann S. , Gore Martin , Kaye Stan B , Banerji Udai
Published: May 2012

Evidence that the phosphoinositide 3-kinase (PI3K) pathway is deregulated in ovarian cancer is largely based on the analysis of surgical specimens sampled at diagnosis and may not reflect the biology of advanced ovarian cancer. We aimed to investigate PI3K signaling in cancer cells isolated from patients with advanced ovarian cancer. Ascites samples were analyzed from 88 patients, of whom 61 received further treatment. Cancer cells were immunomagnetically separated from ascites, and the signaling output of the PI3K pathway was studied by quantifying p-AKT, p-p70S6K, and p-GSK3β by ELISA. Relevant oncogenes, such as PIK3CA and AKT, were sequenced by PCR-amplified mass spectroscopy detection methods. In addition, PIK3CA and AKT2 amplifications and PTEN deletions were analyzed by FISH. p-p70S6K levels were significantly higher in cells from 37 of 61 patients who did not respond to subsequent chemotherapy (0.7184 vs. 0.3496; P = 0.0100), and this difference was greater in patients who had not received previous chemotherapy. PIK3CA and AKT mutations were present in 5% and 0% of samples, respectively. Amplification of PIK3CA and AKT2 and deletion of PTEN was seen in 10%, 10%, and 27% of samples, respectively. Mutations of PIK3CA and amplification of PIK3CA/AKT2 or deletion of PTEN did not correlate with levels of p-AKT, p-p70S6K, and p-GSK3β. In patients with advanced ovarian cancer, there is an association between levels of p-p70S6K and response to subsequent chemotherapy. There is no clear evidence that this is driven specifically by PIK3CA or AKT mutations or by amplifications or deletion of PTEN. Mol Cancer Ther; 11(7); 1609–17. ©2012 AACR.