bluuebunny/crossref_metadata_2025 huggingface dataset:
On a Few Innovations of Chlor-Alkali Membrane Process in Japan
Authors: Kawasaki Nobuhiro , Nakajima Yasuo
Published: May 2013

Two topics about electrode are described as a peculiar problem ofthe chlor-alkali membrane process and one about electrochemicalcorrosion as a general problem of common electrolysis process. Alife of the anode converted from the mercury process was noticedto be short because OH- back-migrating from catholyte through amembrane attacked the conventional RuO2 coated as catalyst on theanode surface of titanium substrate. This problem was solved byIrO2 addition. The authors tried to separate the gas bubblequantitatively into from the electrode and from the membranesurface and obtained the most effective geometry shape ofelectrode to release the gas. Industrial cells are connected by seriesand a shunt current may cause often electrochemical corrosion. Theauthors assembled an electrolysis circuit simulator wherelaboratory rectifiers and auxiliary electrodes are installed. Thissimulator was helpful to reduce shunt current and/or prevent anozzle from electrochemical corrosion.
In Situ Structural Analysis on the Growth Mechanism Pathways of Hydrothermal Synthesized CeO2 Nanocrystals
Authors: Teo Eric Yeow Hwee , Lin Ming , Fu Zi Yuan , Ng Seng Chee , Tan Joyce Pei Ying , Tan Hui Ru
Published: May 2013

In most research, Oswald ripening and/or oriented aggregation processes are used to describe the Ceria (CeO2) nano particles crystals growth mechanism pathway. However, these analysis on the crystals structures and morphologies are done after the hydrothermal reaction, making it challenging to assign the growth pathways of the nano crystals. In this work, we studied the detailed in-situ structural analysis on the growth mechanisms pathways of hydrothermal synthesized CeO2 nanocrystals through the use of electron tomography. Based on the findings, oriented aggregation process plays the primarily role as the mechanism for CeO2 nanocrystals growth in hydrothermal reactions, while Oswald ripening process plays a secondary role in hydrothermal reactions. The study provides a representative pathway for the initial nucleation and growth of CeO2 for hydrothermal process in different synthesis conditions.
Suppression of PbO2 Deposition on Nano-Structured IrO2-Ta2O5/Ti Anodes in Acidic Solutions
Authors: Kawaguchi Kenji , Haarberg Geir Martin , Morimitsu Masatsugu
Published: May 2013

The oxygen evolution behavior and the suppression of anodic PbO2 deposition on IrO2-Ta2O5/Ti anodes, which were prepared by thermal decomposition at different temperatures and metal compositions were investigated in acidic aqueous solutions. Ordered nano IrO2 particles were confirmed in amorphous IrO2-Ta2O5 coatings which were obtained with 50 mol% Ir and calcined at 380 oC by SEM observation with low accelerated electron beam. The amorphization was important to suppress anodic PbO2 deposition, because it was found that the active sites for anodic PbO2 deposition were aggregated IrO2 crystallites while oxygen evolution was accelerated with nano IrO2 particles.
Investigating the Surface Chemistry and Electrocatalysis of Ti/SnO2-Sb2O5 Anode Material
Authors: Ni Qing , Kirk Donald W. , Thorpe Steven J.
Published: May 2013

A mixed metal-oxide anode material, Ti/SnO2-Sb2O5, is a candidate electrode for the electro-oxidation of organic compounds for treatment of wastewater. The catalytic efficiency of this material is dependent on both its surface morphology and surface chemistry. The surface chemistry was studied by photoelectron spectroscopy, and correlated with the electrochemical behavior through scanning voltammetry and impedance spectroscopy. The results showed that the surface activity of the anode material is dependent on the amount of antimony present. The mechanism of electro-catalysis with simultaneous oxygen evolution was also investigated, as this is an undesirable competitive reaction pathway.
Surface Control and Multi-Composite Cathodes
Authors: Mauger Alain , Zaghib Karim , Groult Henri , Julien Christian M
Published: May 2013

We report recent progress in surface control of cathode element particles. Re-crystallization of the surface layer can be obtained not only in olivines, but also in lamellar compounds, which results in an increase of the electrochemical properties. In addition, we take benefit of the stability of LiFePO4 and the fact that it does not need protection against overcharge, by synthesizing multi-component particles formed by a core particle with higher working potential like LiMnPO4 (4 V cell) and even LiMn1.5Ni0.5O4 (5 V cell) surrounded by LiFePO4 coated with carbon to the particles with LiFePO4. The remarkable improvement of the electrochemical properties obtained in this process gives evidence that the synthesis of such multi-component composites are promising to improve the energy density and high-rate performance of Li-ion batteries in the near future.
Bimetallic Sulfates A2M(SO4)2.nH2O (A = Li, Na and M = Transition Metal): as New Attractive Electrode Materials for Li- and Na-Ion Batteries
Authors: Reynaud Marine , Ati Mohamed , Boulineau Sylvain , Sougrati Moulay T. , Melot Brent C. , Rousse Gwenaëlle , Chotard Jean-Noël , Tarascon Jean-Marie
Published: May 2013

Developing the next generations of Li- and Na-ion batteries relies on designing new sustainable, low-cost and safe electrode materials. In such an attempt, we investigated several series of bimetallic sulfates, among them we identified Na2Fe(SO4)2·4H2O, Na2Fe(SO4)2 and Li2Fe(SO4)2, which present attractive electrochemical properties against both lithium and sodium. With a potential of 3.83 V vs. Li+/Li0, the new lithium iron sulfate Li2Fe(SO4)2 displays indeed the highest potential ever obtained for the Fe3+/Fe2+ redox couple in an iron-based fluorine-free compound.
Revisiting the Lithium Iron Borate (LiFeBO3) Cathode System: Synthetic and Electrochemical Findings
Authors: Barpanda Prabeer , Yamashita Yasunobu , Chung Sai-Cheong , Yamada Yuki , Nishimura Shinichi , Yamada Atsuo
Published: May 2013

To realize sustainable synthesis of polyanionic cathode materials, we have designed a solution combustion synthesis to produce cathodes with less energy-demanding annealing conditions. Using it, we have revisited the high-capacity LiFeBO3 cathode system. Due optimization of process parameters have led to the realization of phase-pure LiFeBO3 by using low-cost Fe(III)-based precursor and by restricting the annealing temperature to 400 °C for just 1 hour. The resulting material led to a reversible discharge capacity approaching 200 mAh/g with steady cycling stability. The details of solution combustion prepared LiFeBO3 cathode have been described in brief.
Rechargeable Batteries: From Hybrid Materials to Devices
Authors: Gómez-Romero Pedro , Ruiz Vanesa , Ayyad Omar , Suarez-Guevara J. , Muñoz-Rojas David
Published: May 2013

The hybrid approach allows for a reinforcing combination of properties of dissimilar components in synergic combinations. From hybrid materials to hybrid nanocomposite electrodes the approach offers opportunities to tackle much needed improvements in the performance of energy storage devices. This paper presents different types of hybrid materials with emphasis on those synthesized and studied in our laboratory and reviews the different approaches and scales of hybrids, materials, electrodes and finally presents recent efforts to develop hybrid battery-supercapacitor devices.
Electrochemical Intercalation of Bis(Trifluoromethanesulfonyl) Imide Anion into Various Graphites for Dual-Ion Cells
Authors: Placke Tobias , Fromm Olga , Rothermel Sergej , Schmuelling Guido , Meister Paul , Meyer Hinrich-Wilhelm , Passerini Stefano , Winter Martin
Published: May 2013

Dual-graphite cells have been proposed as electrochemical energy storage devices using graphite as both, the negative and positive electrode. In this setup, the electrolyte cations intercalate into the graphite anode and the electrolyte anions intercalate into the graphite cathode during charge. On discharge, cations and anions are released back into the electrolyte. In this contribution, the electrochemical intercalation of the bis(trifluoromethanesulfonyl) imide anion (TFSI-) into various graphites as cathode from an ionic liquid-based electrolyte, namely N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr14TFSI), was studied. The focus of this investigation is on the influence of the graphite properties such as the particle size and surface characteristics, i. e. the ratio of the basal plane to “non-basal plane” surface area, on the electrochemical performance of TFSI- anion intercalation.
Splash Combustion Synthesis and Exploration of Alkali Metal Pyrophosphate (A2MP2O7, A = Li, Na) Cathodes
Authors: Barpanda Prabeer , Ye Tian , Lu Jiechen , Yamada Yuki , Chung Sai-Cheong , Nishimura Shinichi , Okubo M. , Zhou H. , Yamada Atsuo
Published: May 2013

Pursuing an alternate energy-savvy synthetic route for economic synthesis of polyanionic cathode materials, we have developed a splash combustion synthesis method. It is capable of producing Fe(II) based cathodes starting from cheap Fe(III) precursors under a quick 1-minute high-temperature annealing step. The proof-ofconcept test was carried out on Li2FeP2O7 cathode with success in achieving nanoscale, carbon-coated end-product with reversible discharge capacity of 100 mAh/g. Further, exploiting this synthetic method, we have discovered a novel Na2FeP2O7 cathode with promising electrochemical properties for rechargeable sodium-ion batteries. The details of splash combustion synthesized alkali metal pyrophosphate cathodes are described in a nutshell.
LiMnyFe1-yPO4 Cathode Materials Grown by Hydrothermal Route: Structure and Morphology
Authors: Mathieu Marie-Claude , Trottier Julie , Hovington Pierre , Guerfi Abdelbast , Zaghib Karim , Trudeau Michel , Mauger Alain , Groult Henri , Julien Christian M
Published: May 2013

We report the structure and morphology of the solid-solution series LiMnyFe1EyPO4 isomorphous with olivine synthesized by the hydrothermal route. Experimental studies include combined characterizations such as XRD, FTIR, SEM and HRTEM. Carbon-coated nanoparticles were prepared by the lactose route, which quality was investigated by Raman spectroscopy.
LiMnyFe1-yPO4 (0.5≤y≤0.8) Cathode Materials Grown by Hydrothermal Route: Electrochemical Performance
Authors: Trottier Julie , Mathieu Marie-Claude , Guerfi Abdelbast , Zaghib Karim , Mauger Alain , Julien Christian M
Published: May 2013

We report the electrochemical properties of LiMnyFe1-yPO4 (0.5≤y≤0.8) cathode materials synthesized by hydrothermal route. Special attention was taken to optimize the carbon deposit on the surface of particles in order to make easy comparison of the electrochemical performance as a function composition with the same particle size. The substitution led to the modification of the electrochemical performance, such as initial capacity, capacity fading and polarization. We present the modified Peukert diagrams for C-rate in the range from C/12 to 40C.
Surface and Bulk Properties of LiFePO4: The Magnetic Analysis
Authors: Mauger Alain , Zaghib Karim , Groult Henri , Julien Christian M
Published: May 2013

The magnetic properties of LiFePO4 particles are reviewed. Their analysis is a very efficient tool of characterization of the intrinsic properties of the bulk material. They are also used to identify and determine the concentration of the impurities and of the defects, separately. They are also used to characterize the surface layer, study its crystallinity, and its delithiation upon exposure to moisture.
MnO2 Nano-Rods Prepared by Redox Reaction as Cathodes in Lithium Batteries
Authors: Hashem Ahmed M. , Abuzeid Hanaa M. , Abdel-Latif Abdel M. , Abbas Hekmat M. , Ehrenberg Helmut , Indris Sylvio , Mauger Alain , Groult Henri , Julien Christian M
Published: May 2013

We report the structural and electrochemical of the α- and β-MnO2 phases synthesized by redox reaction of ammonium persulphate with manganese sulphate and manganese nitrate. A single phase of α-MnO2 was observed or the sample prepared from manganese sulphate, while β-MnO2 phase was obtained from manganese nitrate. Characteristic bands of hollandite and rutile phase were observed by FTIR. Nanorods structures were observed by images of transmission electron microscopy for both samples. Good electrochemical performance was observed for β-MnO2, which yields a specific discharge capacity of 180 and 130 mAh g−
1 in the first and 45th cycle respectively. The specific discharge capacity of α-MnO2 is ca. 210 mAh g−
1 at first cycle that decreases to 115 mAh g−
1 in the 45th cycle.
Structural and Electrochemical Characterization of Thermally Treated Vanadium Oxide Nanotubes for Li-Ion Batteries
Authors: McNulty David , Buckley D. Noel , O'Dwyer Colm
Published: May 2013

Vanadium oxide nanotubes (VONTs) have been successfully synthesized by hydrothermal treatment of a mixture of vanadium oxide xerogel and nonylamine. Traditionally dodecylamine and hexadecylamine are used as the structure maintaining template. In this study, however, evidence of high quality nanotubes templated with nonylamine is presented. Thermogravimetric analysis was used to determine the temperature at which the amine molecules can be removed from the nanotubes. The removal of amines is desirable as heavy functionalization of VONTs by amine molecules can impede the intercalation of lithium ions. The removal of the amine chains resulted in a change in morphology from pristine nanotubes to polycrystalline vanadium oxide nanorods. High resolution transmission electron microscopy was used to characterize the VONTs before and after annealing to high temperatures. Fourier transform infrared spectroscopy confirmed the removal of the amine template after annealing. Galvanostatic discharge tests were performed to compare the electrochemical behavior of bulk V2O5 powder, VONTs and polycrystalline nanorods (poly-NRs). A comparison of their specific capacity values after the first discharge is also presented.
Peroxidase Activity of G-Quadruplex Hemin-Binding DNA Aptamers Determined by Electrochemical Measurement
Authors: Kubo Izumi , Eguchi Taiga , Hoshino Yoichiro , Liu Mingzhe , Abe Hiroshi , Ito Yoshihiro
Published: May 2013

Certain guanine-rich DNA oligomers that form a G-quadruplex structure and bind hemin inside are called hemin-binding DNA aptamers. A hemin-binding DNA aptamer with the 4c15 sequence forms a parallel G quadraplex and the PS2.M sequence folds and forms an anti-parallel structure. We propose a novel method to examine the peroxidase activity of hemin-binding DNA aptamers through electrochemical measurements. In this study, a polyA chain and thiol were introcuced to the 5´ terminal of each oligonucleotide. The peroxidase activity of hemin-binding DNA aptamers was determined after modifying a gold electrode with the aptamers. The distance to hemin from the surface of the electrode is most important to determine catalytic activity. Catalytic activity, shown as KM of the examined parallel DNA aptamers, was around 20 μM. 4c15 without a poly A linker showed the highest catalytic activity, and its KM was 19 μM. The KM of the anti-parallel aptamer was almost the same as that of the parallel aptamer.
Au Nanoparticle-based Detection of Human Chorionic Gonadotropin Using Electrochemical Impedance Spectroscopy
Authors: Li Nan , Li Qi , Chen Xavier Ran , Veloso Anthony J. , Hung Vinci Wing Sze , Dhar Devjani , Kerman Kagan
Published: May 2013

A disposable screen-printed carbon electrode (SPCE) for point-of-care detection platform was developed for human chorionic gonadotropin (hCG). A sandwich assay employing gold-nanoparticles was characterized with differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). hCG was analyzed between 100 pg/mL and 1 ng/mL, and a detection limit of 100 pg/mL was observed with 2-µL sample volume. This versatile platform can be easily adapted for decentralized electrochemical immunosensing of clinically important hormones.
Self-Assembled Synthetic Protein Scaffolds: Biosynthesis and Applications
Authors: Su Wei Wen , Han Zhenlin
Published: May 2013

Scaffold proteins play an important role in diverse cellular processes. Their unique molecular architecture helps to organize functionally interacting proteins in space and time. The resulting self-assembled protein complexes perform a wide variety of unique cellular functions. Inspired by these naturally occurring protein scaffolds, there has been an increasing interest in the development of novel artificial protein scaffolds for both in-vivo and in-vitro applications. Here two different molecular assembly strategies for effective biosynthesis of novel protein scaffolds are discussed. These scaffolds include amyloid-like nanofibril scaffolds and nano-scale oleosomal scaffolds derived from biological protein-bound lipid droplets synthesized in vivo. By recruiting protein components with distinctive functions (e.g. targeting, catalytic, and/or reporting) on the same scaffold, one can create intricate nanofactories to carry out novel tasks, including complex electrochemical biosensing.
Fabrication of Semi-Invasive Micro-Needle Array Using Gradation Exposure
Authors: Yamaguchi Masaki , Sasaki Yugo , Kimura Yuta , Sasaki Makoto , Nakayama Yuki
Published: May 2013

The authors have been investigating a methodology to fabricate a micro-needle array on a thin plastic film for clinical use. The lithography-based approach can be used to produce micro-needle arrays. The purpose of this research is to demonstrate a methodology for etching silicon to particular required depths which can be used in designing structures to manufacture a mold for polymers. A grey-scale photolithography technique was demonstrated using deep reactive ion etching (DRIE). The whole photo-lithography process was carried out in two steps: (i) a photoresist pattern was transferred into silicon dioxide using a layout mask, (ii) a silicon mold was formed using exposure through the use of gradation mask and DRIE. The etch selectivity to the resist was 8.1 and the maximum relative depth was 30 μm.
High Temperature Oxidation of Ferritic Steels for Solid Oxide Electrolysis Stacks
Authors: Molin Sebastian , Chen Ming , Bentzen Janet Jonna , Hendriksen Peter Vang
Published: May 2013

Oxidation rates of ferritic steels used as interconnector plates in Solid Oxide Electrolysis Stacks are of concern as they may be determining for the life time of the technology. In this study oxidation experiments were carried out for up to 1000 hours in hydrogen-side and oxygen-side simulated atmospheres at 800°C. Four commercially available alloys: Crofer 22 APU, Crofer 22 H, AL29-4, E-Brite were characterized in humidified hydrogen. One alloy, Crofer 22 APU was also characterized in pure oxygen both in the as-prepared state and after application of a protective coating. Best corrosion resistance in humidified hydrogen atmosphere was observed for Crofer 22 APU and Crofer 22 H alloys. Corrosion rates for Crofer 22 APU measured in humidified hydrogen are similar to the corrosion rates measured in air. Both coatings of plasma sprayed LSM and dual layer coatings (Co3O4/LSM-Co3O4) applied by wet spraying were found to reduce corrosion rates in pure oxygen significantly.
On the Shape of Stress Corrosion Cracks in Water-Cooled Nuclear Power Reactor Piping
Authors: Lee Sang-Kwon , Kramer Daniel , Macdonald Digby D.
Published: May 2013

The evolution of the shape of surface cracks in sensitized Type 304 SS in Boiling Water Reactor primary coolant at 288 oC was explored as a function of the corrosion potential and stress intensity using the Coupled Environment Fracture Model (CEFM). The revised CEFM that incorporates Shoji’s model for calculating the crack tip strain rate and more advanced expressions for estimating the stress intensity factor for semi-elliptical surface cracks provides more accurate prediction of the dependence of the crack growth rate on stress intensity factor and offers an alternative explanation for the development of semi-elliptical cracks than that provided by fracture mechanics. The evolution of the shape of surface cracks depends strongly upon environmental variables, such as the corrosion potential, predicting that the minor axis of the ellipse should be oriented perpendicular to the surface due to the dependence of the crack growth rate on the electrochemical crack length.
Electrochemical Impedance Modeling of the Passivity of Carbon Steel in Simulated Concrete Pore Water
Authors: Macdonald Digby D. , Sharifi-Asl Samin , Almarzooqi Ahmed , Engelhardt George R. , Kursten Bruno
Published: May 2013

The prediction of corrosion damage to times that are experimentally inaccessible by a large factor (e.g., to over 1000 years) is vitally important in assessing various concepts for the disposal of High Level Nuclear Waste. Such prediction can only be made using deterministic models, whose predictions are constrained to being “physically real” by the natural laws [conservation of mass, energy, charge and mass-charge equivalence (Faraday’s Law)]. In this paper, we describe the measurement of experimental data that will allow the deterministic prediction of damage to the carbon steel overpack of the super container in Belgium’s proposed Boom Clay repository by using the Point Defect Model to extrapolate damage to future times. We also describe an experimental program that is designed to generate values for various PDM parameters for the corrosion of carbon steel and stainless steel that will be required in making the damage predictions.
The Effect of Thermal Hydrogenation Processing on the Oxide Layer Formation of Ti-6Al-4V Alloy
Authors: Tsai C.J. , Yu S.S. , Wang L.M. , Shen C.C.
Published: May 2013

In this work, we study the correlation of corrosion resistance, characterization of related oxide layer and microstructure mainly using thermohydrogen processing (THP) plus common industrial heat treatment of Ti-6Al-4V alloy. It appears that better corrosion resistance and higher hardness of Ti-6Al-4V alloy can be achieved by post-THP annealing treatment associated with controlled oxidation reaction at 704°C which leads to formation of significant thinner and denser oxide layer with increased amount of TiO2, Al2O3, and V2O5.
Synthesis and Electrochemical Properties of Ni Doped Spinel LiNixMn2-xO4 (0 ≤ x ≤ 0.5) Cathode Materials for Li-Ion Battery
Authors: Kebede Mesfin Abayneh , Kunjuzwa Niki , Ozoemena Kenneth Ikechukwu , Mathe Mkhulu K.
Published: May 2013

Spherical pristine LiMn2O4 and Ni doped LiNixMn2-xO4 (x=0.1, 0.2, 0.3, 0.4, 0.5) cathode materials for lithium ion battery with high first cycle discharge capacity and excellent cycle performance were synthesized using the solution-combustion technique. XRD analysis revealed peak shift towards higher angle and lattice shrink as a result of Ni doping. CSAFM result confirms LiNi0.5Mn1.5O4 provides higher current of 10nA than pristine LiMn2O4 of 0.05nA. The EIS result displays that small Ni content (x=0.1, 0.2) doping reduced the impedances of pristine LiMn2O4. The composition LiNi0.1Mn1.9O4 exhibits higher capacity and better cycleability than other Ni content compositions. Charge/discharge cycling result shows that Ni substitution substantially improved the capacity retention of LiMn2O4. All Ni doped LiNixMn2-xO4 (x= 0.1, 0.2, 0.3, 0.4, 0.5) compositions are able to retain 99% of their respective first cycle discharge capacities, whereas LiMn2O4 retains only 60% of its first cycle discharge capacity of 122 mAh/g after 50 cycles.
Graphene-Quantum Dots Composite for Photovoltaic Devices
Authors: Guo Shirui , Wang Wei , Guvenc Ali Bilge , Kyle Jennifer Reiber , Ozkan Cengiz , Ozkan Mihrimah
Published: May 2013

Large-area flexible and transparent optoelectronic devices were fabricated through non-covalent interaction between CdSe/ZnS core/shell quantum dots and single layer graphene. The photo-induced charge transfer was confirmed by fluorescence quenching experiments and photoconductivity measurements. Quantum dots decorated graphene device exhibits excellent photo-switching property making it promising as a long wavelength sensitive photodetector. 1-D (graphene)/ 0-D (QD) hybrid structure facilitates electron transfer faster. When used as photoelectrochemical cell anode, this hybrid material displays both high photon to current conversion efficiency (IPCE) and fast photo-switch response.
Development of Electrically Controlled Energetic Materials (ECEM)
Authors: Chung Kimberly , Rozumov Eugene , Kaminsky Dana , Anderson Paul , Cook Paula , Sawka Wayne , McPherson Michael , Buescher Trisha
Published: May 2013

U.S. Army ARDEC has been examining a novel pyroelectric-type material developed by Digital Solid State Propulsion, LLC for its unique combustion properties and insensitivity. This unique ECEM is formed using an ionic liquid oxidizer and polymer fuel, via sol-gel processes and is quite dense, making it very suitable for energetic applications in both the civilian and military fields. This ECEM is completely insensitive to the application of impact, flame, friction, and shock threats. Once a power of the required voltage is applied, the baseline ECEM rapidly initiates combustion with H2O, CO2, and N2 formed as the only major gas phase products produced. Initial testing of ECEM in perforated pipes appears promising as indicated by uniform ignition along the entire length of the test assembly.
Spatio-Time-Resolved Cathodoluminescence Studies on Freestanding GaN Substrates Grown by Hydride Vapor Phase Epitaxy
Authors: Chichibu Shigefusa F , Ishikawa Yoichi , Tashiro Masanori , Hazu Kouji , Furusawa Kentaro , Namirta Hideo , Nagao Satoru , Fujito Kenji , Uedono Akira
Published: May 2013

A spatio-time-resolved cathodoluminescence (STRCL) system was constructed by replacing the electron beam (e-beam) gun of a conventional scanning electron microscope by the in-house manufactured pulsed e-beam gun, which is excited using femtosecond laser pulses. By using this system, STRCL measurements were carried out on low threading dislocation density freestanding GaN substrates grown by hydride vapor phase epitaxy. High-resolution cathodoluminescence imaging allows for visualization of nonradiative recombination channels in the vicinity of accidentally formed domain boundaries. Local cathodoluminescence lifetimes (τCL) for the near-band-edge (NBE) emission are shown to be sensitively position dependent. A linear relation between the equivalent internal quantum efficiency (ηint
eq) and τCL for the NBE emission was observed at room temperature under a weak excitation condition, and spatially resolved excitation led to the observation of the highest ηint
eq of 20 % with τCL of 3.3 ns.
High Color Rendering White LED Based on Silicate/Dye-Bridged Siloxane Hybrid Phosphor Encapsulant
Authors: Bae Byeong-Soo , Kwak Seung-Yeon , Kim Na Ree , Im Hyeon-Gyun
Published: May 2013

White light-emitting diodes (LEDs) attract much attention as next generation lighting. Among many components constructing white LED, phosphors have a key role to generate white emission combining with blue LED. We report a red dye-bridged siloxane hybrid (DBH) as a red emitter and white LEDs based on red DBH mixed with green silicate phosphor. Red DBH has a potential to alternate inorganic phosphors and quantum dots used as red emitter in white LEDs because it has merit on cost and broad emission and absorption. The silicate/DBH phosphor encapsulated white LEDs exhibit high color rendering index up to 90 and easy color tunability.
Synthesis and Luminescence of Eu2+ Activated Yellow Oxynitride Phosphor
Authors: Nammalwar Prasanth Kumar , Satya Kishore Manepalli , Porob Digamber , Setlur A.A , Santamaria F. Garcia
Published: May 2013

In this paper, we discuss synthesis and luminescence properties of a novel yellow phosphor composition, Ba4Si9(O,N)16-
d:Eu2+ (YON). The powder x-ray diffraction pattern indicates formation of a new oxynitride phase with a minor secondary phase of BaSi7N10 . To our knowledge, the composition and luminescence properties of this oxynitride material has not been reported earlier. YON crystallizes in monoclinic crystal system with unit cell parameters a=5.7598(1)Å, b=7.0499(1)Å, c=9.6315(1)Å, b = 107.362(1). The Eu2+ activated material shows efficient yellow emission peaking around ~580nm under UV/blue excitation. The emission position can be tuned by Sr2+/Ca2+ substitution in the Ba2+ site. We also investigate the nature of their emission at different Eu2+ concentration levels and at elevated temperatures. Warm white lamps built using phosphor blends with this new phosphor are capable of making high CRI, warm white lamps with high lumen equivalents (>325 lm/Wopt).
The Formation of the Hexagonal Pyramid Facets on Wet Etching Patterned Sapphire Substrate
Authors: Chen Yu-Chung , Hsiao Feng-Ching , Wu YewChung Sermon
Published: May 2013

Currently, the wet etching patterned sapphire substrate (PSS) has attracted much attention for its high production yield. After etching in hot mixed H2SO4 and H3PO4 solution, the several etched facets were exposed on sapphire substrate. In this study, a series of etching process was used to investigate the formation. As shown in Fig. 1, when SiO2 mask still remained, the structure of PSS comprised of six facets {3-417}. When SiO2 mask were etched away, beside six facets, there were three extra facets {1-105} exposed on the top.
Characterizations of Al2O3/ZnO Grown on Si Substrate by Plasma Enhanced Atomic Layer Deposition
Authors: Chung Chen-Chen , Tran Binh Tinh , Lin Kung Liang , Wang Ching-Chiun , Chen Chien-Chih , Huang Chih-Yung , Lee Sheng-Lang , Yi Chang Edward
Published: May 2013

Several characterizations of nanolaminate Al2O3/ZnO oxide films grown on Si substrates by using plasma enhanced atomic layer deposition (PE-ALD) method were studied. PE-ALD can minimize the structural imperfections in films and reduce substrate damage. The film deposition by using PE-ALD are dense, defect-free, highly uniform, conformal films and show excellent step coverage. Moreover, compared to other deposition techniques, it is possible to deposit high quality films at much lower temperatures. The High resolution transmission electron microscope (TEM) images showed the existence of sharp interfacial layers among the Al2O3, ZnO layer, and the Si substrate for the growth rate of 1.56 Å/cycle, and the surface roughness of about 0.2 nm. The nanolaminate-stacking layer can be used in OLED encapsulation application as the gas barrier.
Glancing Angle Sputter Deposition of Titanium Dioxide Films for Photocatalytic Applications
Authors: Yasuda Yoji , Kitahara Naoto , Hoshi Yoichi
Published: May 2013

Here, the nanostructure of TiO2 photocatalytic films was controlled for photocatalytic applications using glancing angle sputter deposition and oxygen-ion–assisted reactive evaporation (OARE). The grain size and surface asperity both increase as the deposition angle increases, and films with high porosity were obtained at high incidence angles. However, the film deposited using sputtering has a much larger column diameter and a denser structure than the film deposited using OARE. Therefore, the film deposited using glancing angle sputter deposition at an incidence angle of 80° had much better photocatalytic properties than the film deposited using OARE: it was superhydrophilic after 1 h of UV irradiation and showed excellent organic decomposition performance. An increase in the porosity of this film led to a significant increase in its UV absorptance, which also improved its photocatalytic performance. In particular, the film deposited at 80° using sputtering had a UV absorptance above 70%.
LbL Film with PtNPs as a Sensor of the Dopamine Encapsulated in Liposomes
Authors: dos Santos Vagner , dos Santos Monalisa , Sandrino Bianca , de Jesus Cliciane Guadalupe , Garcia Jarem Raul , Fujiwara Sérgio Toshio , Pessôa Christiana Andrade , Wonhrath Karen
Published: May 2013

The detection of dopamine (DA) encapsulated in liposomes prepared by the hydrating of a thin film of dipalmitoyl phosphatidylcholine (DPPC) with DA solution, was investigated using LbL films containing sulphonate p-phenylenevinylene (PPV-SO3) and the hybrid formed by incorporation platinum nanoparticles (PtNPs) in the cavities of chloride-3-n-propylpyridiniumsisesquioxane polymer (SiPy+Cl-), designed as PPV/Pt-SiPy+Cl-. The LbL films of (PPV/Pt-SiPy+Cl-)n deposited on FTO was applied as sensors to detection of free and encapsulated DA into liposomes. The LbL films with 3 bilayers (PPV/Pt-SiPy+Cl-)3 present higher current values for DA oxidation (Ipa = 76 µA) and higher separation between the oxidation potential of the DA (0.97 V) and the oxidation potential of the ascorbic acid (AA) and uric acid (UA) interferences (1.60 V) (∆pa = 630 mV). The separation of the oxidation peak potentials for DA and interferences decreases to 320 mV when the DA is encapsulated in liposome. This behavior can be explained by approximation of the liposomes to electrode surface which can influences in the interaction between the Pt-SiPy+Cl- from (PPV/Pt-SiPy+Cl-)3 LbL film and the AA and AU interferences.
Synthesis and Physical Properties of Ionic Liquid Gels Based on Novel Low Molecular Weight Gelators
Authors: Yoshida Tomohiro , Hirakawa Tomomi , Nakamura Toru , Yamada Yasuhiro , Tatsuno Hiroko , Morita Yuki , Okamoto Hiroaki
Published: May 2013

Low molecular weight organic compounds 1-n and 2-n having 2-(perfluoroalkyl)ethyl groups at both terminal positions were prepared and their gelation ability was examined. Compounds 1-n and 2-n gelate various ionic liquids and/or organic solvents at low concentration, while they have no hydrogen bonding group required for conventional organic gelators. Compounds 1-n gelate alcoholic and polar solvents, however, these are difficult to gelate ionic liquids and only 1-12 formed a gel in [BMIM][TFSA]. On the other hand, compounds 2-n gelate ionic liquids as well as organic solvents and the gelation ability in ionic liquids is higher than that of organic solvents. The formed gels are a physical gel with a thermally reversible sol-gel phase transition. Furthermore, ionic liquid gel electrolyte using compounds 1-n or 2-n as a gelator was prepared and the ionic conductivity of these gel electrolytes and that of the corresponding ionic liquid electrolyte were examined.
Solvent Extraction Using Microchannel System for High Purification of Silica
Authors: Matsuo Nobufumi , Matsui Yuki , Fukunaka Yasuhiro , Homma T.
Published: May 2013

We present solvent extraction using a microchannel device for purification of silica, focusing upon boron extraction with 2-ethyl-1,3-hexanediol (EHD). Boron was successfully eliminated from the samples, which consists of silica and boric acid as well as refined diatomaceous earth. The residual boron content after the extraction using a microchannel device was lower than that using a conventional separatory funnel, although the contact reaction period was much shorter. It is suggested microchannel device is an attractive method to produce high-purified silica for solar grade silicon.
Control of the Morphology of Si Nanostructure Using Single-Step Metal Assisted Etching Method
Authors: Yamaguchi Takuya , Shimizu Tomohiro , Inoue Fumihiro , Wang Chonge , Otsuka Shintaro , Tada Yoshiro , Morosawa Y. , Takase Kouichi , Inada Mitsuru , Shingubara Shoso
Published: May 2013

The morphological changes of etched Si surfaces on the concentration of AgNO3 using single-step metal assisted etching and their reflectance were investigated. We used aqueous mixture solution containing silver nitrate (AgNO3) and hydrofluoric acid (HF) as single-step metal assisted etching solution. With changing concentration of silver ions in the etching solution, three types of Si surface morphologies (“nanowire”, “wall”, “polished”) were prepared. Then, phase diagram is developed for these morphologies obtained as a function of AgNO3 concentration and resistivity of silicon substrates. The measurement of reflectance for etched surface indicates that the nanowire is the lowest reflectance of three types of morphologies.
The Effect of the Deposition Conditions on the Electrodeposition of Si Nanopillars in TMHATFSI
Authors: Ishibashi Yoko , Akiyoshi Takahiro , Komadina Jason , Fukunaka Yasuhiro , Homma T.
Published: May 2013

Si nanopillars were prepared by electrodeposition from SiCl4 in an ionic liquid, specifically tri-methyl-n-hexyl ammonium bis-(trifluorosulfonyl) imide (TMHATFSI), and the effects of the various deposition conditions, such as bath temperature and deposition potential, were investigated. For the preparation of the patterned substrates, UV-nanoimprint lithography was employed. The thickness of resist was 90-100 nm, mold feature diameter was 150 nm, with a pitch of 450 nm. As a result, compact Si nanopillars were uniformly electrodeposited, and it was indicated that their morphology were affected mostly by the bath temperature.
Corrosion of Copper and Nickel During Electroless NiP/Pd Deposition
Authors: Tiwari Chandra S , Nguyen Robert
Published: May 2013

Corrosion of copper (Cu) and nickel (Ni) during electroless nickel-phosphorous/palladium (NiP-Pd) deposition on bond pads has been investigated. Both Ni and Cu corrosion occurred during the drying process, but the cause of corrosion was different for each metal. Nickel corrosion occurred from aqueous residue from Pd bath and rinse while copper corrosion occurred due to condensation of vapors from heated aqua regia chemistry used for cleaning electroless tanks. Corroded metal and corrosion byproducts were analyzed by AES, FIB and TEM to understand corrosion mechanism.
Impact of the Silicon Substrates and Activation in the Nickel Electroless Plating
Authors: El Belghiti Hanane , Aureau Damien , Bouttemy Muriel , Delbos Elise , Etcheberry Arnaud
Published: May 2013

Our purpose is to deposit a very well-controlled thickness of electroless nickel to form contact lines for silicon solar cells. For that, an accurate understanding of the nickel electroless mechanism is necessary. The main step is to control the beginning of nickel nucleation at very short times. In this study, a commercial bath was employed. First, we have demonstrated that a too oxidized silicon surface block the nickel deposition. Then, the first steps of nucleation were finely studied using both SEM-FEG and XPS analyses. And to finish, a nickel electroless deposition mechanism was proposed.
Photo-Electrochemical Deposition Behaviour of Metal Silver on Polypyrrole as Conducting Polymer
Authors: Kawakita Jin , Fujihira Hiroshi , Chikyow Toyohiro , Sakamoto Yukihiro
Published: May 2013

Composite of metal and conducting polymer is expected for the electrical application by the use of their advantages. The purpose of this research was to reveal photo-electrochemical deposition behavior of metal, which is important to control the formation rate and the composite’s structure obtained by simultaneous metal deposition and polymerization under the photo-irradiation. Cathodic polarization curves for silver deposition on polypyrrole film with different substrates under UV irradiation were compared in addition to the electrical resistance of the polypyrrole and the substrate. Morphology of silver deposition on polypyrrole was characterized by microscopic observation. The experimental results showed that photo introduction to polypyrrole upon silver deposition enhanced the deposition rate to 24 times at maximum.
Paneth cells expand from newly created and preexisting cells during repair after doxorubicin-induced damage
Authors: King Stephanie L. , Mohiuddin Jahan J. , Dekaney Christopher M.
Published: May 2013

Paneth cell numbers increase following intestinal damage, but mechanisms driving this process are not understood. We hypothesized that the increase in Paneth cell numbers is due to recruitment of cells from a preexisting pool of secretory progenitors. Mice were given a single injection of doxorubicin (Dox), and intestinal tissue was collected 0–168 h after treatment. Paneth, goblet, and intermediate cells were counted and evaluated for cell morphology. Quantitative RT-PCR was used to measure expression of various genes associated with Paneth cell allocation and maturation. Paneth cells were birth dated using incorporation of thymidine analogs given before or after Dox. Staining revealed “intermediate” cells, which were rarely observed in control crypts but increased significantly in number 96 and 120 h after Dox treatment. Birth dating of intermediate cells 5 days after Dox treatment revealed that 24% of these cells took up thymidine analog given prior to Dox treatment and 36% took up thymidine analog given after Dox treatment. Quantitative RT-PCR demonstrated a significant increase in Spdef, Atoh1, Sox9, EphB3, Mist, Wnt5a, FGF-9, and FGF-18 mRNAs and a significant decrease in Indian hedgehog mRNA. Expansion of the Paneth cell compartment after Dox treatment is due to generation of new cells and recruitment of cells from an existing pool. These cells express Paneth and goblet biomarkers and are found only during repair. Expansion of these cells correlates temporally with reduced Indian hedgehog and increased FGF and Wnt mRNA. These findings are significant, as they provide a first step in understanding mechanisms of Paneth cell expansion during mucosal repair.
Arm movements can increase leg muscle activity during submaximal recumbent stepping in neurologically intact individuals
Authors: Kam Digna de , Rijken Hennie , Manintveld Toos , Nienhuis Bart , Dietz Volker , Duysens Jacques
Published: May 2013

Facilitation of leg muscle activity by active arm movements during locomotor tasks could be beneficial during gait rehabilitation after spinal cord injury. The present study explored the effects of arm movements on leg muscle activity during submaximal recumbent stepping. Healthy subjects exercised on a recumbent stepping machine both with and without arm movements. Activity of five leg muscles was recorded and compared for stepping with and without arm movements. To determine which arm movements are optimal for leg muscle facilitation, subjects were instructed to step with 1) mechanically coupled vs. decoupled arm and leg movements, 2) synchronous vs. asynchronous arm movements, and 3) at 50 vs. 70 RPM. Leg muscle activity was increased by active arm movements in all muscles, except the vastus lateralis muscle. Activity of other extensors (soleus, medial gastrocnemius, and biceps femoris) was primarily increased during the extension phase, whereas activity of flexors (tibialis anterior) was also increased during the flexion phase. Facilitation was more or less consistent for both frequencies and for synchronous and asynchronous movements. For coupled arm movements, facilitation tended to be diminished or absent. The observed facilitation in the present study is probably of neuromuscular rather than biomechanical origin, since the arms are probably hardly involved in postural control or weight-bearing during recumbent stepping. Further studies in patients should explore the possibility to integrate neuromuscular facilitation in rehabilitation programs.
A Multicenter, First-in-Pediatrics, Phase 1, Pharmacokinetic and Pharmacodynamic Study of Ridaforolimus in Patients with Refractory Solid Tumors
Authors: Gore Lia , Trippett Tanya M. , Katzenstein Howard M. , Boklan Jessica , Narendran Aru , Smith Amy , Macy Margaret E. , Rolla Katherine ,   for the Pediatric Oncology Experimental Therapeutics Investigators' Consortium (POETIC), Narashimhan Narayana , Squillace Rachel M. , Turner Christopher D. , Haluska Frank G. , Nieder Michael
Published: May 2013

Purpose: Ridaforolimus (MK-8669, AP23573) is a potent and selective mammalian target of rapamycin (mTOR) inhibitor. Preclinically, ridaforolimus displays antiproliferative activity against a variety of human tumors in vitro and tumor xenograft models in vivo, with additive or synergistic activity when combined with other anticancer agents. Antitumor activity has been confirmed in adults. This phase I study determined the safety, pharmacological, biologic, and toxicity profiles of ridaforolimus in pediatric patients with refractory malignancies.

Experimental Design: Eligible children ages 1 to 18 years with advanced solid tumors were enrolled in a 3 + 3 dose escalation design, to determine the safety, tolerability, and maximum tolerated dose (MTD)/dose-limiting toxicity (DLT) of ridaforolimus. Toxicities, pharmacokinetics, and pharmacodynamics were characterized.

Results: Fifteen patients were treated. No DLT was observed at any dose level tested; therefore, an MTD was not identified. Most adverse events were mild to moderate; the most common grades 3 and 4 adverse events were hematologic, including thrombocytopenia and anemia. Nonhematologic adverse events were mostly electrolyte disturbances. The observed pharmacokinetic profile of ridaforolimus in children was consistent with that previously showed in adults. Pharmacodynamic confirms that the dose range tested has pharmacological/pharmacodynamic activity. Forty percent of patients achieved stable disease including four of six with central nervous system tumors and two of eight with sarcomas.

Conclusions: This first-in-pediatrics study shows that the second-generation mTOR inhibitor ridaforolimus is well tolerated in heavily pretreated children with refractory solid tumors. No DLTs were observed over the dose range tested. Ridaforolimus may represent a therapeutic option for use in pediatric malignancies. Clin Cancer Res; 19(13); 3649–58. ©2013 AACR.
Identifying the Ubiquitin Ligase Complex That Regulates the NF1 Tumor Suppressor and Ras
Authors: Hollstein Pablo E. , Cichowski Karen
Published: May 2013

The NF1 tumor suppressor protein neurofibromin is a negative regulator of Ras. Neurofibromin is dynamically regulated by the proteasome, and its degradation and reexpression are essential for maintaining appropriate levels of Ras-GTP. Like p53, NF1/neurofibromin can be inactivated in cancer by both mutations and excessive proteasomal destruction; however, little is known about the mechanisms that underlie this latter process. Here, we show that a Cullin 3 (Cul3)/kelch repeat and BTB domain-containing 7 complex controls both the regulated proteasomal degradation of neurofibromin and the pathogenic destabilization of neurofibromin in glioblastomas. Importantly, RNAi-mediated Cul3 ablation and a dominant-negative Cul3 directly stabilize neurofibromin, suppress Ras and extracellular signal-regulated kinase, and inhibit proliferation in an NF1-dependent manner. Moreover, in glioblastomas where neurofibromin is chronically destabilized, Cul3 inhibition restabilizes the protein and suppresses tumor development. Collectively, these studies show a previously unrecognized role for Cul3 in regulating Ras and provide a molecular framework that can be exploited to develop potential cancer therapies.

Significance: This study identifies the ubiquitin ligase complex that controls the regulated and pathogenic destruction of the NF1 tumor suppressor protein. These observations provide a molecular framework for developing potential therapies for glioblastoma, where neurofibromin is chronically destabilized, and reveal a new strategy to attenuate Ras that has broader therapeutic implications. Cancer Discov; 3(8); 880–93. ©2013 AACR.

This article is highlighted in the In This Issue feature, p. 826