bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Tellurium Dioxide Nanoparticles by Spray Pyrolysis
Authors: Zhang Hongwang , Swihart M. T.
Published: February 2007

Tellurite glasses (amorphous tellurium dioxide based materials) have two useful optical properties, high refractive index and high optical nonlinearity, that make them attractive for a range of applications. Unlike other metal oxide nanoparticles that are prepared in large quantities by vapor phase processes, Telluria nanoparticles have not been prepared by such methods. Here, we describe the vapor-phase synthesis of telluria nanoparticles from a dilute solution of telluric acid that is dispersed into fine droplets by an atomizer. These droplets are carried through a furnace, where they evaporate and where the precursors react to nucleate telluria particles. The nanoparticles were characterized by TEM, XPS, FTIR and XRD. The effects of operating parameters on nanoparticle composition, production rate and size were also studied. This laboratory-scale process is capable of producing milligram to gram quantities of amorphous telluria nanoparticles with primary particle diameters from 10 to 40 nm.
Synthesis of Zinc Sulfide Nanoparticles by Spray Pyrolysis
Authors: Zhang Hongwang , Yong Ken-Tye , Swihart M. T.
Published: February 2007

Zinc sulfide is a II-VI semiconductor with a direct band gap in the near-UV region. Here, we demonstrate the preparation of ZnS nanoparticles (NPs) by spray pyrolysis using zinc diethyldithiocarbamate as a single-source precursor. Solutions of this precursor in toluene are dispersed into fine droplets by an atomizer, and then carried into a tube furnace where they evaporate fully. ZnS NPs then nucleate from the vapor phase. The NPs were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and optical spectroscopies. The NPs are about 3 - 20 nm in diameter and are crystalline, as indicated by the presence of lattice fringes in HRTEM, and by selective-area electron diffraction. Their XRD pattern shows a single peak, indexed to the (111) plane of the cubic zinc blende lattice. The UV absorption spectrum shows peaks in the range of 330-380 nm, and the NP's exhibit bright blue photoluminescent emission under UV illumination.
Influence of Water and Pyridine Addition on the Hydrogen Overvoltage on Iron in the Ethylene Glycol Solutions of HCl
Authors: Tsygankova Liudmila , Vigdorovich Vladimir , Zarapina Irina , Shel Natalia
Published: February 2007

The influence of the water concentration (0.15-50 wt.%) and pyridine one (0.5-10 mM) on the hydrogen overvoltage (η) on iron has been studied in the ethylene glycol - water solutions of HCl (0.05-0.99 M). The measurements were conducted in the solutions with the constant ionic strength equal to 1 (LiCl was used) and in the hydrogen atmosphere at the room temperature. The rate-determining step of the HER and η depend on the concentration of water and pyridine in the solutions.
Corrosion Protection of Bronze Patina by New Non-Toxic Organic Inhibitors
Authors: Stupnisek-Lisac Ema , Tadic Katarina , Otmacic Helena , Mance Ana Dunja , Takenouti Hisasi
Published: February 2007

From antiquity bronzes have been widely used to produce sculptures and others objects of art. Bronze artefacts are generally covered with a patina. The patina formed in a long term exposition acquired often a certain protective effect of the substrate metal, but a recent increase of air pollution and/or acid rain damage the bronze exposed in urban environment. A method that reinforces a protective effectiveness of patina becomes therefore necessary. In order to preserve metal works from the aggressive atmosphere, organic inhibitors are often required. The inhibiting effects of two non-toxic organic inhibitors: 1- phenyl-4-methylimidazole and 1-(p-tolyl)-4-methylimidazole on the patina were examined by potentiodynamic methods and electrochemical impedance spectroscopy as well as spectroscopic methods. The morphology and crystallographic structure of artificially obtained patina without and with inhibitor layer were examined with SEM and EDS analyses. The results of these investigations have shown that both studied inhibitors protect patina in aggressive media.
Influence of Flow Velocity of Electrolyte on Roughness and Morphology of High-speed Electrogalvazing Deposit
Authors: Zhu Xiaodong , Li Ning , Li Deyu , Li Wei
Published: February 2007

Abstract: High-speed electrogalvazing have attracted increasing interest from the automobile industry and steelmakers because of it's high efficiency and excellent mechanical properties. Flow velocity of electrolyte is closely related to the coating properties especially roughness and texture. Effect of flow velocity of sulfate electrolyte electrogalvazing on morphology, roughness and crystal orientation of zinc deposit, was studied with self-made simulative gravity high-speed plating bath. The results showed that effect of flow velocity on micromorphology of zinc deposit was evident: High velocity got dense and smooth deposit, while slow velocity resulted in rough and convexoconcave one. Foremost in this study, it was found that there was linear decline of deposit roughness with the increase of flow velocity, the formula of this relationship established in this paper was: Ra=a+bv, further study on which confirmed the discipline of effect of deposit thickness and current density on deposit roughness.
Theory of Passive Film Stability
Authors: Macdonald Digby D.
Published: February 2007

Some of the physico-electrochemical properties of passive oxide films that form on reactive metal and alloy surfaces, and which protect the underlying metals from reaction with corrosive environments, are reviewed within the context of the Point Defect Model (PDM). This model yields analytical expressions for the steady state current and film thickness and for the transients in these properties that can be used to predict deterministically the accumulation of general corrosion damage to metal surfaces, provided that the evolutionary path to the future state is continuous and can be specified. The conditions under which passivity may exist are defined in terms of Phase Space Analysis (PSA) of the PDM and it is found that passivity is invariably a meta-stable phenomenon. PSA leads to the development of Kinetic Stability Diagrams (KSDs) as alternatives to the equilibrium thermodynamic Pourbaix diagrams that are now used to describe the conditions under which passivity is observed.
Anodic Dissolution of Nickel Across Two Consecutive Electron Transfers: Calculation of the Ni(I) Intermediate Concentration by means EQCM
Authors: Gregori Joan , Garcia-Jareño Jose Juan , Gimenez-Romero David , Vicente Francisco
Published: February 2007

The analysis of the Electrochemical Quartz Crystal Microbalance (EQCM) and Electrochemical Impedance Spectroscopy (EIS) results are consistent with a nickel electrodissolution process limited by the passage of Ni(I) to Ni(II), when chloride ions are present in the acid sulphate medium, or by the passage of Ni(II) to Ni2+ in solution, in absence of chloride. This interpretation allows explaining the potential evolution of Fdm/dQ values in both experimental conditions by assuming the formation of a new phase on the electrode surface with a gel-like structure placed between the metal and the solution. Ni(I) surface concentration is calculated from the instantaneous mass/charge Fdm/dQ values.
Analysis of Discolored and Corroded Components
Authors: Suess Steven J.
Published: February 2007

Discoloration and corrosion of components can lead to a wide variety of problems, ranging from poor cosmetic appearance to complete deterioration. Whether a component undergoes superficial surface discoloration or severe corrosion, a systematic approach is needed in order to properly identify the cause of the problem so that proper corrective measures can be taken. Many different analysis techniques are available for characterizing surface discoloration and corrosion deposits, and the proper use of the appropriate techniques will greatly increase the likelihood of correctly identifying the physical cause of the problem. This article details an effective failure analysis process for evaluating discolored and corroded parts.
Electrochemical Behavior Of Mg-Al-Zn Alloy AZ91 In H3PO4/KOH Buffered K2SO4 Solutions
Authors: Anik Mustafa , C¸elikten Gizem
Published: February 2007

The DC polarization and AC EIS techniques were used to analyze the electrochemical reaction behavior of Alloy AZ91 in H3PO4/KOH buffered K2SO4 solution at pH 7. The corrosion resistance of Alloy AZ91 was directly related with the stability of Al2O3.xH2O rich part of the composite oxide/hydroxide layer on the alloy surface. The mf capacitive loop arose from the relaxation of mass transport in the solid oxide phase. The lf inductive loop had tendency of disappear when the dissolution rate of the alloy decreased as a result of the formation of the protective oxide layer.
The Influence of the Marine Aerobic Pseudomonas Strain on the Corrosion of 70/30 Cu-Ni Alloy
Authors: Yuan Shaojun , Choong Mei Fun, Amy , Pehkonen Simo Olavi
Published: February 2007

Corrosion of 70/30 Cu-Ni alloy by marine aerobic bacteria Pseudomonas sp. NCIMB 2021 in an artificial seawater medium was investigated by electrochemical and microscopic methods. Polarization curve measurements demonstrated that the corrosion rate of the alloy increased notably in the presence of the Pseudomonas sp. by the acceleration of both the anodic and cathodic reactions. The impedance spectra and the corresponding equivalent circuits confirmed that the alloy surface in the sterile medium comprised of an outer organic compound conditioning layer and an inner compact and protective oxide film layer; while in the Pseudomonas inoculated medium, a duplex layer of an outer porous, heterogeneous and non-protective biofilm layer and an inner porous oxide film layer was present. Both the charge transfer resistance, Rct, and the resistance of the porous oxide film, Rpo, decreased with exposure time, indicating an acceleration of corrosion due to the marine bacteria. Bacteria attached to the alloy surface formed blotchy biofilms, as observed by fluorescent microscopy. The dynamic development of the biofilm and surface roughness were monitored by atomic force microscopy. Scanning electron microscopy images showed micro- pitting corrosion on the alloy surface after the biofilm remova
Iron Diffusion Profile Studies by Surface Photo-Voltage for Silicon Iron Implanted Wafers After Rapid Thermal Anneal
Authors: Rapoport Igor , Taylor Patrick , Kim Seung-Bae , Orschel Benno , Huber W.
Published: February 2007

Two-side Surface Photovoltage (TS-SPV) based on measuring SPV from both wafer sides is proposed as novel approach for silicon surface contamination monitoring. TS-SPV is applied to investigate the process of diffusion of implanted iron in lightly doped p-type silicon during Rapid Thermal Anneal (RTA). Good correlation was found for iron distribution vs. RTA conditions in the temperature range from 375 to 1100oC. The portion of electrically active interstitial iron measured by TS-SPV was studied as function of RTA time and temperature conditions. Low thermal budget RTA combined with TS-SPV is proven to be effective to monitor iron contamination and to identify the contamination sources character and location.
Self-seeding Crystallization of Silicon Thin Films Using Continuous-Wave Laser
Authors: Kuroki Shin-Ichiro , Fujii Shuntaro , Kotani Koji , Ito Takashi
Published: February 2007

Low temperature crystallization of amorphous silicon thin films using continuous-wave laser was investigated. An overlapping of laser beam exposure enhanced the crystallization of a polycrystalline Si thin film, and the silicon crystal nucleus grew its size laterally. A laser beam spot had an elliptical shape for a gradual slope of temperature in a laser irradiated region, and was elongated to a scanning direction. The elongated laser spot with a gradual slope of temperature made a crystallization time longer. Consequently, a two dimensional lateral crystallization of (100) well-oriented Si thin films was achieved.
Nano-Grating Channel MOSFETs for Improved Current Drivability
Authors: Ito Takashi , Kuroki Shin-Ichiro , Kotani Koji
Published: February 2007

Drivability-improved MOSFETs were successfully fabricated using nano-grating silicon wafers. Effective channel widths were increased by using the wafers. This required almost no additional process change for device fabrication when the grating height was less than or comparable to the conventional macroscopic wafer surface roughness. The fabricated MOSFET with 25nm grating height showed 22 % improvement in current drivability compared to the conventional device.
Encapsulation of Carotenoids in Single-wall Carbon Nanotubes and their Optical Properties
Authors: Yanagi Kazuhiro , Miyata Yasumitsu , Kataura Hiromichi
Published: February 2007

Carotenoids are encapsulated inside single-wall carbon nanotubes (SWCNTs). Their structure and optical properties in SWCNTs are clarified by Raman, optical absorption spectroscopy and X-ray diffraction profiles. Degradation of carotenoids is a bottleneck impeding their device application but we revealed that the stability of carotenoids is highly improved by encapsulation into SWCNTs. Moreover they do exhibit a light- harvesting function inside SWCNTs. These novel findings will open the door for the fine-tuning, via the encapsulation of various molecules, of the optical properties of SWCNTs for numerous optoelectronic applications.
Light-induced Current in Long Carbon Nanotubes
Authors: Wei Jinquan , Wu Dehai , Wang Zhicheng , Luo Jianbin , Wang Kunlin
Published: February 2007

Evident light-induced current through a long carbon nanotubes (CNTs) bundle was observed when it was induced by a laser from visible to far infrared. The property of the photocurrent is negative for SWNTs, while it is always positive for MWNTs. The photocurrent of the CNTs is strongly influenced by the power and wavelength of the light. The response time of the photocurrent for the SWNTs is much faster than those for the MWNTs.
Vibrational Structure in the Electronic Spectra of C60 and Fullerene Derivatives as Studied by Time-Dependent Density Functional Theory
Authors: Popov Alexey A. , Korepanov Vitaly , Senyavin Vladimir M. , Troyanov Sergey , Razbirin B. S. , Ovchinnikova N. , Yurovskaya M. A. , Starukhin A. N.
Published: February 2007

Vibronic spectra of C60, C60Cl30 and two N- methylfulleropyrrolidines are studied with the use of TD-DFT. PBE/TZ2P approach is found to be a suitable technique for prediction of the vibronic spectra of fullerene derivatives, both for Herzberg-Teller and Frank-Condon mechanisms.
Heat Transfer Nanolubricant and Nanogrease Based On Carbon Nanotube
Authors: Hong Haiping , Wensel Jesse , Roy Walter
Published: February 2007

In this paper, we report the effort to prepare a stable and homogeneous heat transfer nanolubricant and nanogrease in the oils (e.g. DURASYN® 166) with the motivation of enhancing its properties such as thermal conductivity and lubricity. The process of making these fluids involves the dispersion of carbon nanoparticles into the oil through intermittent sonication and the use of additives such as surfactants.
Solid State Dye Sensitized Solar Cells Using Poly (3-hexylthiophene) as Hole Transport Material
Authors: Neugebauer Helmut , Günes Serap , Sariciftci Serdar
Published: February 2007

Solid state dye sensitized solar cells have been fabricated using a ruthenium dye complex, RuL2(NCS)/TBA(2:2) (where L= 2,2′-bipyridyl-4,4′-dicarboxylic acid; TBA= tetrabutylammonium), as a sensitizer and poly(3- hexylthiophene) (P3HT) as a hole transporting layer with TiO2 electrodes as electron transporting layers. We have studied the photovoltaic properties of P3HT/dye coated TiO2 electrodes and P3HT coated TiO2 electrodes with and without using compact TiO2 layers. The compact TiO2 layer improved the photovoltaic performance of the devices.
Ionic Conductivities of Solid Polymer Electrolyte/Salt Systems for Lithium Secondary Battery : Electrostatic Potential Contribution
Authors: Lee Seung Seok , Bae Young Chan , Sun Yang Kook
Published: February 2007

We establish a thermodynamic model of ionic conductivities model for solid polymer electrolyte/salt systems based on modified double lattice (MDL) model. The proposed model takes into account both the mobility and the charge interactions of the solid polymer electrolyte/salt systems. The interactions between Li ion and polymer molecules are described by electrostatic potential (ES) when Li ion is passing by a polymeric membrane. In comparison with experimental data, quantitative descriptions of the proposed model show better agreement for the given systems than those of existing models.
pH Metric Study of Complexe Formation of Some Alkali and Alkaline Earth Metal with two Dicarboxylic Acid Ligands
Authors: Shabani Rostam , Abbasdpour Abdolkarim , Sharghi Hashem
Published: February 2007

The stability constants of two dicarboxylic acid ligands (1,7- Bis (2¢-benzoic acid)-1,4,7-trioxaheptane (L1) and 1,10-Bis(2¢- benzoic acid)-1,4,7,10-tetraoxadecane(L2)) with Na+, K+, Ca2+ and Mg2+ in ethanol - water solvent mixtures were determined. The ratio of ligand / metal in these complexes is 1/1, and the stability constants of K+ with L1 and L2 are higher than Na+ and the stability constants of Ca2+ with L1 and L2 are higher than Mg2+ complexes. These studies also showed that the stability constants of Na+ and K+ complexes with L1 and L2 increases by an increase in the mole fraction of ethanol in the solvent mixtures. Key Words: Stability Constant, 1,7-Bis (2¢-benzoic acid)-1,4,7- trioxaheptane and 1,10-Bis(2¢-benzoic acid)-1,4,7,10- tetraoxadecane, Potentiometry
Arsenic Analysis and Speciation by Field Deployable Nano-Band Electrode System
Authors: Gomes Jewel A. , Cocke David , Varma Sudharshan , Moreno Hector , Peterson Eric
Published: February 2007

Arsenic has long been an USEPA priority pollutant and is an important environmental concern because of its toxicity and carcinogenicity even at parts per billion levels. The combination of high toxicity and widespread occurrence has created a pressing need for effective monitoring and measurement of arsenic in soils and groundwater. Speciation of the oxidation states of arsenic is very important for better understanding of its chemical behavior, abundance and distribution in groundwater, and its removal mechanism. In the present work, a relatively new nano-band electrode system has been optimized for the determination of both As(III) and As(V) in water samples using Anodic Stripping Voltammetric technique. The influence of deposition potential, different supporting electrolytes and plate time on the arsenic stripping peak was investigated. A detection limit of 0.4 ppb has been obtained using USEPA method of detection limit, with plate times of just 10 seconds. The major interference was found to be from copper during measurements. Finally, the optimized system has been used for arsenic determination and speciation in real water samples, such as Rio Grande basin water, and electrocoagulation solutions.
Nickel Cathode Passivation in Alkaline Water Electrolysis
Authors: Kirk Donald W. , Thorpe Steven
Published: February 2007

During water electrolysis in alkaline electrolytes, nickel cathodes deactivate over time. The presence of soluble iron species in the alkaline electrolyte mitigates the deactivation. Congruently, iron deposits are observed on the Ni electrodes. The role of the iron deposits in preventing deactivation is explored in this work. Nickel deactivation has been proposed to be due to the formation of a surface Ni hydride phase. A complete coating of metallic iron is known to prevent nickel electrode deactivation. In industrial electrolysis, however, there is never complete coverage of the Ni electrode by iron deposition. In this work, we focused on determining the extent of iron surface coverage required to prevent nickel deactivation. A metallic grid placed over the nickel electrodes during iron vacuum sputtering was used to achieve iron coverages ranging from 20 to 100%.
Controlling Ionic Currents with Transistor-like Structures
Authors: Grebel Haim , Zhang Yan
Published: February 2007

Control scheme of ionic currents in a new three-terminal electrochemical cell is proposed. This is achieved by introducing a permeable, multi-layered structure which has electronic doping, such as, p-n-p or n-p-n between the typically two biasing electrodes. Ionic currents were controlled by applying a base voltage between the middle layer and an outer (working) electrode at a given potential between the two outer electrodes (fixed biasing potential). We demonstrated this approach for corrosion and plating processes, however, we envision that such construction may be useful for other membrane applications.
Phage Fusion Proteins As Bioselective Receptors For Piezoelectric Sensors
Authors: Olsen Eric V. , Sykora Jennifer , Sorokulova Iryna , Neely William , Petrenko Valery , Chen I-Hsuan , Barbaree James , Vodyanoy Vitaly
Published: February 2007

Filamentous phage affinity-selected for streptavidin and Salmonella typhimurium from phage display libraries were transformed with chloroform into spherical forms then deposited as phage coat protein monolayers to quartz crystal microbalances (QCM) by Langmuir-Blodgett (LB) to prepare bioselective sensors. Maximum yield of spheroids was achieved by mixing 8.3 x 10-11 to 2.5 x 10-12 filamentous phage virions/ml with 1 ml chloroform for 60 seconds. Spheroid conversion and binding to S. typhimurium was confirmed by transmission electron microscopy. Phage coat monolayers incorporating phospholipid possessed high elasticity and transference to QCM substrates comparable to antibodies. Sensor responses to increasing concentrations of target analytes were characterized by rapid reaction, steady-state equilibrium, high sensitivity, and linear dose-response that followed mass theory for piezoelectric transducers. Scanning electron microscopy confirmed binding of target analytes to biosensors compared to controls. Phage-based sensors may allow detection of bacterial agents such as S. typhimurium in food safety and security applications.
Aluminum Nitride Thin Film for Stress Biosensing Application
Authors: Ou Keng-Liang , Liu Chung-Ming , Chen Chin-Sung , Lin Che-Tong , Lee Sheng-Yang
Published: February 2007

The microstructural properties and functional failure of Al-N thin films metal-insulator-metal (MIM) capacitors fabricated by reactive-sputtering were studied for the application as differential biosensing of bone cell. The film properties and capacitor capability of Al-N films with and without cell culture were determined using glancing incident X-ray diffraction (GIXRD), leakage current density, cross-sectional transmission electron microscopy (XTEM), and stress analysis as well as biocompatibility test. The as-deposited Al film has a face-center cubic structure and a low resistivity of 3.21 μΩ- cm. With increasing nitrogen concentration of Al-N films, phase transformations are identified as fcc-Al→fcc-Al(N)→ fcc-AlN → hcp-AlN. As the testing result of MIM capacitor, it was manifested that the failure of the AlN MIM capacitors was caused microvoids formed on the film after cell culture. The microvoid having occurred at the cell/AlN MIM capacitor caused it to leak out much of the current to the extent of a few microamperes even at 150k V/cm. The formation of microvoid and low break down voltage was explained by the stress variation during the cell differentiation and proliferation. The stress induced by interaction bone cell and hcp-AlN film resulted in lattice and/or atomic displacement and distortion of AlN. It is believed that the [002] oriented AlN film is shown to perform effectively as a biosensing film to detect the cell differentiation and proliferation by MIM capacitor device. Furthermore, the biosensing film will have a potential for use in wireless technology to monitor the osseointegration in the future.
Electrochemically Induced Self-organized Nanostructures on Silicon for Realization of a Novel Nanoemitter Solar Cell Concept
Authors: Skorupska Katarzyna , Aggour Mohammed , Kanis Michael , Lublow Michael , Jungblut Helmut , Lewerenz Hans, Joachim J.
Published: February 2007

Oscillatory behaviour of silicon electrodes in fluoride containing solution results in formation of nanoporous oxides. Metal electrodeposition into these pores results in local Schottky junction formation. Metal nanoemitters are contacted with a transparent conductive oxide and aluminum contact fingers for preparation of the first device (Al/ZnO/Pt-SiO2/Si/GaIn/Ag). Present solar-to-electrical conversion efficiencies are small and various improvement possibilities are outlined.
SAXS/DSC Study of Polymer Electrolyte for Zn Rechargeable Nanostructured Galvanic Cells
Authors: Turkovic Aleksandra , Pavlovic Mladen , Dubcek Pavo , Lucic-Lavcevic Magdy , Etlinger Bozidar , Bernstorff Sigrid
Published: February 2007

(PEO)8ZnCl2 polymer electrolytes and nano-composites were prepared using PEO g-irradiated to selected dose of 309 KGy and TiO2 nanograins. The influence of added nanosize TiO2 grains to polymer electrolytes and the effect of g-radiation from a Co- 60 source were studied by small-angle X-ray scattering (SAXS) simultaneously recorded with differential scanning calorimetry (DSC) at synchrotron ELETTRA. Impedance spectroscopy (IS) was also performed. Above-mentioned treatments largely enhanced the conductivity of polymer electrolyte. Room temperature conductivity increase up to two orders of magnitude was achieved. Addition of nanograins increased conductivity more than can be ascribed to crystallinity possibly because of interactions of anion with nanograins.
Characterization and Luminescent Properties of YPO4:Eu3+ Nanocrystals Prepared by Combustion Method
Authors: Sharma Gaytri , Han Sang-Do , Khatkar S.P , Rhee Young Woo
Published: February 2007

A new route (combustion method) consists of the redox reaction between the respective metal nitrates and urea in a preheated furnace at 500oC was investigated for the synthesis of YPO4:Eu3+ nanocrystals. The nanocrystals thus obtained were then fired at different temperatures from 700oC-900oC for 3 hrs to get better luminescent properties. The incorporation of Eu3+ activator in these nanocrystals was checked by luminescence investigations. Scanning electron microscopy (SEM) studies were carried out to understand surface morphological features and the particle size. The average particle size was less than 25nm. In addition to this, crystal structures of the nanocrystals were also studied by X-ray diffraction (XRD) for different dopant concentrations.
Preparation of Green, Yellow and Red Long Persistent Nanophosphors
Authors: Jia Dongdong , Wilhelm Justin , Freed Jacqueline , Best Dustin E. , Goonewardene Anura
Published: February 2007

Long persistent nanophosphors of ZnS:Cu+ (Green), ZnO:Mn2+ (Yellow) and CaO:Eu3+ (Red) were prepared through precipitation method. n-heptane was used as a stabilizer to control the particle growth. Green emission of Cu+ in ZnS was found at 506 nm, yellow emission of Mn2+ in ZnO was found at 572 nm, and red emission of Eu3+ in CaO is found at 616 nm. The average growth rate of CaO nanophosphor was 4.72 nm3/s. Adding a stabilizer can stop the particle growth and aggregation. Smaller particle size was obtained by adding n- Heptanes at earlier time.
Stereoselective Introduction of Hydroxyl Group to Piperidine Ring using Electrochemical Method
Authors: Matsumura Y. , Ogino Takashi , Libendi Samuel S. , Onomura Osamu
Published: February 2007

Electrochemical oxidation of 2-substituted 1-benzyloxycarbonyl- 1,2,3,4-tetrahydropyridines under aqueous conditions using I- as a mediator preferentially afforded 6-substituted 1- benzyloxycarbonyl-2,3-dihydroxypiperidines with a stereochemistry of cis-relationship between the 3-OH and 6- substituent, while the direct electrochemical oxidation resulted in a trans-relationship of the products. Electrochemical method was compared with conventional oxidation such as hydroboration, oxidation by OsO4 and m- chloroperbenzoic acid, all of which predominantly gave products having trans-stereochemistry.
Some Progress and Development on Synthetic Electroorganic Chemistry
Authors: Nishiguchi Ikuzo
Published: February 2007

The series of electroorganic reactions, as shown in this paper, have been developed directed towards organic synthesis for these thirty years in the author's half-life. They consist of five sections, such as 1) selective introduction of functional groups by anodic oxidation, 2) Mn3+- and halonium ion-mediated carbon-carbon bond formation of activated Olefins by anodic oxidation, 3) intramolecular cyclization by electroreduction of non- conjugated enones and eynoes, 4) selective one-pot double C-acylation of activated olefins by electroreduction, and 5) novel transformation of organic compounds and synthetic application, which may be characterized by novelty, interests, noteworthiness, and originality.
Indirect Electrosynthesis of Para-Methoxybenaldehyde from Para-methoxytoluene using Cr2O72-/Cr3+ Mediator
Authors: Su Leon , Zhang Yuanjing , Hu Ruisheng , Wang Jiangxiang
Published: February 2007

Indirect electrosynthesis of p-methoxybenaldehyde from p- methoxytoluene (p-MT) using Cr2O72-/Cr3+ mediator in sulfuric acid is developed here. Effects of H2SO4 concentration, molar ratios of Cr2O72- to p-MT, reaction temperature and reaction time on the yield of p-methoxybenzaldehyde are investigated. The results show that under the conditions that molar ratio of (Cr2O72-) to (p-CH3O-C6H4-CH3) is 1:6, concentration of sulfuric acid is 2 M, reaction temperature is 80 ºC and reaction time is 80 min, the yield of p-methoxybenzaldehyde is 90%.
On the Electrochemistry of 2,4,6-triphenylnitrobenzene
Authors: Lund Henning
Published: February 2007

Cyclic voltammetry at a glassy carbon electrode of 2,4,6- triphenylnitrobenzene (1) in DMF shows two reversible one- electron reductions. Preparative reduction of 1 yields 2,4,6- triphenylaniline under both acidic and alkaline conditions and in DMF in the presence of acetic anhydride. On reduction in dry DMF is formed a stable, violet radical anion with a broad maximum at 682 nm 2,4,6-Triphenylaniline shows in CV in acetonitrile a reversible oxidation; in acetonitrile containing pyridine it is oxidized to azo(2,4,6-triphenylbenzene). This compound is in acidic aqueous DMF reduced to 2,4,6- triphenylaniline. The three phenyl groups act as electron donating groups during reductions akin to p-hydroxy or p-amino groups.
The Quest for Electrodes Coated with Vitamin B12 Derivatives
Authors: Keese Reinhart , Siegenthaler Hans , Luginbühl Reto , Rashid Abdur M. , Schnippering Mathias
Published: February 2007

The electrochemical control of the redox reactions of vitamin B12 and derivatives thereof plays an important role for the in vivo investigations of the B12 dependent biological transformations. While most of these studies were performed in solution, electrodes coated with appropriate B12 derivatives are of more recent interest. A survey of our results in preparing electrodes bearing B12 derivatives is given. Structural features of the surface coating are discussed. Some of the electrodes show catalytic activity for the reduction of oxygen.
Search for a One-Electron Reduction of the Cation Radical of an	Extended Viologen , p-Phenylene-bis-4,4'-(1-Aryl-2,6-Diphenylpyridinium)
Authors: Pospíšil Lubomír , Hromadová Magdaléna , Fiedler Jan , Gál Miroslav , Valášek M. , Pecka J. , Michl Josef
Published: February 2007

Electrochemical one-electron reduction of the extended viologen dication 1^2+ proceeds reversibly at -0.64 V (vs. Ag|AgCl electrode) to yield the red cation radical 1^+. , which readily produces a dark blue dimer hindering the observation of a second one-electron reduction of 1^+.. Conventional electrochemical methods suggest that the only second reduction step occurs at -1.4 V. Fast cyclic voltammetry at scan rates up to kV/s and voltammetry at micromolar concentrations eliminate the coupled bimolecular chemical reactions and permit the determination of the reduction potential of the cation radical 1^+. .
Reductive Cleavage of Halides in Decomposition of Substituted Benzonitrile Pesticides
Authors: Sokolova Romana , Machnikova Eva , Fiedler Jan , Hromadova Magdalena , Giannarelli Stefania , Pospisil Lubomir
Published: February 2007

The reduction mechanism of chloroxynil (3,5 dichloro 4 hydroxy- benzonitrile), bromoxynil (3,5 dibromo 4 hydroxybenzonitrile) and ioxynil (3,5-diiodo-4-hydroxybenzonitrile) was studied in dimethylsulfoxide by the electrochemical methods combined with spectroelectrochemical and GC/MS identification of the products. DC polarography shows two irreversible reduction waves for ioxynil and only one reduction wave for bromoxynil and chloroxynil. Cyclic voltammetry at different scan rates and at various concentrations of pesticides is consistent with the radical anion formation followed by the subsequent chemical reactions. The main decomposition pathway includes the cleavage of the halogen atom and the dimerization of the dehalogenated intermediate. The differences in the mechanism of ioxynil, bromoxynil and chloroxynil are caused by the mutual differences in the rates of the bond cleavage and the dimerization process.
Fabrication of Si Structures with Vertical Side-walls using Single Long Plasma Etch
Authors: Agarwal Rahul , Samson Scott , Bhansali S.
Published: February 2007

A new approach to etch structures with vertical sidewalls in Si is presented. This process reduces the loading effect in Deep Reactive Ion Etching (DRIE) and maintains uniform etch profile and etch rate through out the wafer. Rectangular areas were patterned under the regions to be removed. Uniform width channels encompassing these rectangular patterns were then subjected to long DRIE. These uniform width narrow channels maintain uniform etch rates while patterning structures with various fill factors on the same wafer. Average side wall angles of 89.8{degree sign} were obtained with just 0.3{degree sign} variation across the 4 Si wafer. The process showed resistance to slight variations in DRIE parameters with negligible effect on the sidewall profile. The etched vertical mirrors are used to assemble a Corner Cube Retroreflector.
An Electrochemical Sensor Array for In-situ Measurements of Oxide Film Electric Resistance in High Temperature Water
Authors: Uchida Shunsuke , Satoh Tomonori , Miyazawa Takahiro , Satoh Yoshiyuki , Kakinuma Nagao , Mäkelä Kari
Published: February 2007

Corrosive conditions in primary cooling systems of boiling water reactors are determined by oxidants, e.g., O2, H2O2 and other corrosive radiolytic species. A high temperature high pressure water loop, which controls H2O2 concentration with minimal O2 co-existence, was constructed in order to evaluate the effects of H2O2 on corrosive conditions, and then static and dynamic responses of stainless steel specimens exposed to H2O2 and O2 in high temperature pure water were evaluated by analyzing ECP (electrochemical corrosion potential) and FDCI (frequency dependent complex impedance). At the same time, in- situ measurements were carried out to determine changes in oxide film electric resistance. From the multilateral high temperature measurements, it was concluded that H2O2 concentrations could be determined by in- situ measurement based on a sensor complex for ECP and FDCI and that ECP and [H2O2] data could be used to evaluate occurrence and propagation of intergranular corrosion cracking of reactor internal components.
A Novel Additive to Improve the Performance of LiFePO4 in Li-ion Battery
Authors: Dong Quan-Feng , Liu Shan-Ke , Zheng Ming-Sen , Zhan Ya-Ding , Sun Shi-Gang , Lin Zu-Geng , Zhu Ya-Wei
Published: February 2007

Pure LiFePO4 and LiFePO4/CaB6 composites with different contents of CaB6 were synthesized by solid sate reaction. The samples were characterized by the granularity, morphology, electric conductivity, tap density, X-ray diffraction and electrochemical performance. The results showed that not only the rate performance of LiFePO4 was increased with doping CaB6, but also was the tap density and electronic conductivity improved significantly. The sample doped 3% CaB6 showed the best performance, its electronic conductivity was increased by five orders of magnitude and the tap density by 65%.
Analyses of Au/Si Schottky Barrier-Induced AC Surface Photovoltages in N-Type Silicon Wafers Rinsed in Au Aqueous Solution
Authors: Shimizu H. , Omori Eri , Ikeda Masanori
Published: February 2007

Alternating current (AC) surface photovoltages (SPV) were investigated on n-type (001) Si wafers rinsed in Au aqueous solution. Au ions (Au3+) accept electrons (Au3+ + 3e- →Au) by the difference of oxidation-reduction potential, causing Au/n-type Si Schottky barrier. The Au/n-type Si Schottky barrier is found to cause frequency-dependent AC SPV, demonstrating that the Si surface was depleted and/or weakly inverted. The surface potential of Si is calculated to be -0.45{plus minus}0.2 eV. Thus, Schottky type band diagram is obtained between Au and n-type Si, resulting in barrier height of 0.73~0.76 eV.
Evaluation of Composite Membrane with Three-Dimensionally Ordered Polyimide Matrix and AMPS Gel Polymer for Direct Methanol Fuel Cell
Authors: Yamamoto Dai , Munakata Hirokazu , Kanamura Kiyoshi
Published: February 2007

A new proton conducting composite electrolyte membrane consisting of three-dimensionally ordered macroporous (3DOM) polyimide matrix and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) gel polymer has been fabricated. Two types of gel polymers with different cross linker concentration were prepared. The composite membrane exhibited higher morphological stability against water and methanol absorption, and lower methanol permeability than that of Nafion ® membrane in any cross linker concentration due to suppressing polymer expansion by polyimide matrix. Furthermore, the composite membrane showed very high conductivity at least 1.1 x 10-1 S cm-1 at 60 degree C under 90% relative humidity. The effect of cross linker concentration was compensated between methanol permeability and proton conductivity.
Energy Technology Division Research Award Address: Photoelectrochemical Storage of Solar Energy
Authors: Licht Stuart
Published: February 2007

Societal energy demands are depleting fossil fuels and inducing global warming, and drive the need for alternate, clean societal energy sources. Photovoltaic processes, of conventional solar cells, induce electronic charge transfer. Alternatively, photoelectrochemical systems drive both electronic as well as faradaic charge transfer. This provides the basis for semiconductor/electrolyte systems, which, via electrochemical oxidation/reduction, can convert and/or store solar energy. This overview of photoelectrochemical charge storage processes will include (i) solution phase theory of photoelectrochemical energy conversion, (ii) photoelectrochemical cells with in-situ storage, improved through the theory and experiment of high efficiency multibandgap photoelectrochemistry, and (iii) our studies on solar generation of hydrogen fuel.
Application of [C4min][Tf2N] Ionic Liquid as Thermal Storage and Heat Transfer Fluids
Authors: Zhang Mingming , Reddy Ramana
Published: February 2007

Imidazolium ionic liquids with [Tf2N]- anions were synthesized and characterized using nuclear magnetic resonance (NMR) spectrometer, differential thermal analysis (DTA) and differential scanning calorimeter (DSC). Properties of these ILs such as thermal stabilities, heat capacities and thermodynamic properties were measured. Feasibility of these ILs as liquid thermal storage and heat transfer fluids was investigated. It is found that [C4min][Tf2N] has several advantages over other ILs such as wider liquidus temperature range, lower viscosity, higher chemical stability, moderate heat capacity and storage density. The calculated storage densities for [C4min][Tf2N] was more than 180 MJ/m3 when the inlet and outlet field temperature are 210{degree sign}C and 310oC. Based on our experimental results, it can be concluded that ionic liquids are suitable as liquid thermal storage and heat transfer fluids in solar power generation applications.
Electrochemical Lithium Insertion of Iron Oxide Spinel Thin Films and Nanoparticles: Changes in Structure and Magnetic Properties
Authors: Sivakumar Vikram , Kumar Sundeep , Ross Caroline , Shao-Horn Yang
Published: February 2007

Fe2O3-x spinel-structure thin films grown by pulsed laser deposition (PLD) and commercially available magnetite nanoparticles were subjected to electrochemical lithiation at room temperature. A substantial decrease in saturation magnetization (Ms) was observed both in the PLD-grown thin films and nanoparticles on lithiation. Further, lithiation of PLD-grown thin films and nanoparticles has resulted in a reduction in intensity of the 311, 220 and 440 reflections in XRD. A decrease in Ms of up to 30% for thin films and 75% for nanoparticles has been observed by discharging down to 0.9 V versus Li/Li+. The decrease in saturation magnetization upon lithiation may be due to formation of a paramagnetic phase. The smaller drop in Ms observed in thin films could be a kinetic effect due to the high density of the PLD-grown films and hence lithiation of only the surface layers.
Combinatorial Discovery of Platinum Alloy Electrocatalysts for Oxygen Electro-reduction
Authors: He Ting , Kreidler Eric , Xiong Liufeng , Ding Errun
Published: February 2007

The oxygen electro-reduction properties of various platinum alloys were studied using a combinatorial high throughput method. Binary and ternary platinum alloys were fabricated using a multi-source physical vapor deposition system and the resulting thin film samples were electrochemically screened by the hydrodynamic rotating disk electrode technique. By comparing the activity-stability-composition relationship between these alloys and a pure platinum film, over 10 alloy catalyst candidates were identified with mass-fraction specific activities of 5 to 10 times that of pure platinum. Additionally, organometallic synthesis methods have been studied to synthesize carbon supported alloy nanoparticles. A good relationship of the molecular oxygen electro-reduction has been found between alloy thin film and powder catalysts.
New Bimetallic Catalysts for the Oxygen Reduction Reaction (ORR) Based on Ni and Pt Carbide: Synthesis, Characterization and Electrochemical Studies
Authors: Di Noto Vito , Negro Enrico , Gliubizzi Rocco , Lavina Sandra , Pace Giuseppe
Published: February 2007

A novel synthesis route yielding materials suitable for use as catalysts for the oxygen reduction reaction (ORR) in fuel cells is reported. A reaction between two inorganic salts in the presence of an organic binder leads to a metallorganic precursor, which is subsequently thermally decomposed to produce the final material. The temperature of the final thermal treatment step was found to be a critical parameter influencing the efficiency of the electrocatalyst in the ORR; the range between 400{degree sign}C and 700{degree sign}C was explored. A thorough analysis of the chemical composition of the products demonstrated that this synthesis route can yield materials having the desired metal composition. The determination of the electrochemical efficiency towards the ORR showed that several of the materials produced through this synthesis route have an overall activity much higher than that of commercial electrocatalysts with a similar platinum content.
Composite Cathode Structure/Property Relationships
Authors: Babinec Susan J. , Tang Houxiang , Meyers Greg , Hughes Stephanie , Talik Andrew
Published: February 2007

Battery active materials are routinely evaluated via the electrochemical performance of their composite electrodes which are prepared with standard formulations and routine processing conditions. The relationship between electrochemical responses and these experimental variables are not commonly explored. Mechanical properties and their relationship to durability are almost never considered. We therefore offer some quite basic studies of the effects of formulation on these properties. Electrochemical and mechanical properties of composites across a broad formulation range are provided for the most common Li-Ion chemistry - LiCoO2 electroactive particles with PVDF binders. Mechanical characterizations include evaluations of both the constituent materials and the porous electrode structures. We will show that composite electrode designs which optimize mechanical durability and ruggedness will degrade electrochemical performance for these LiCoO2/PVDF binder- based systems.
Electrochemical Investigation of Non-equilibrium Surface States of Matter.
Authors: Burke Laurence D. , Garbarino Sebastian , Kinsella Louise , Naser Nageb S.
Published: February 2007

High energy, non-equilibrium, surface states of metals, which are assumed to be associated with surface defect sites, have not received a great deal of attention in surface electrochemistry. Such states, which are assumed to be the basis of active site behaviour, are minority surface species which display redox (or faradaic) behaviour that is quite different from the conventional response of the majority surface state, i.e. similar atoms present in equilibrated form at the same surface. The effect of enhancing the coverage of the high energy surface state is illustrated, as is the role of such states in electrocatalysis, plating bath additive behaviour and the operation of metastable metal oxide electrodes such as ruthenium dioxide cathodes. Non-equilibrium surface states are difficult to control and investigate as they evidently involve quite low coverage, rather labile, surface species which are not easily imaged by STM.
Electrical Characterization of Nano Structured Energy Storage Devices
Authors: Lee Jaeheon , Bartley Kenneth L. , Palusinski Olgierd A.
Published: February 2007

Templated nano structures are being developed as nanotechnology device platforms and include porous membrane structures such as polycarbonate (PC), polyethylene terephthalate (PET), and alumina. Copper wires have been successfully grown inside the pores of these membranes with nano diameter dimensions using an electrodeposition process (1). A device made from this structure, called a digitated energy storage device (DESD) has been built and tested. There is a great amount of interest in building energy storage devices for pulse-power needs. The obvious example is hybrid vehicles where both high-energy stroage and power demands are needed. The cost of using a battery for pulse-power has been a sacrifice in energy density and life-cycle (2). Improvements in energy storage efficiency, via exploitation of nanoscale structures, will provide the high power and long cycle-life not found in batteries.
Modeling the Plasma Electrolytic Oxidation of Aluminium and Magnesium Alloys
Authors: Caire Jean-Pierre , Dalard Francis , Minko Wilfried Sathurnin
Published: February 2007

A numerical model was developed to simulate the plasma electrolytic oxidizing of aluminium and magnesium alloys in direct current galvanostatic mode. The model based on the analysis of acoustic emission assumes that during plasma oxidizing the dielectric breakdown is due to the increase of electric field appearing at the barrier layer situated at the bottom of pores. The model simulates the pore growth by use of an equivalent resistive network. This very simple model includes nevertheless no less than eleven ill-known physical parameters leading to a difficult calibration. Though the model was not yet calibrated, it reproduced fairly well the experimental results, particularly the beginning of anodization. The numerous assumptions made to build the model were confirmed by the preliminary results. The particularly difficult calibration of this model is in progress and will be published soon.