Physical Sciences and Mathematics Commons^™

Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm Γ Mno 2 Obtained By Microemulsion Method, Liu Ling, Xia Xi

Journal of Electrochemistry

A nanophase MnO 2 was synthesized using w/o microemulsion as reation media, The most favorable experiment conditions for the preparation of nm MnO 2 were researched. XRD,TEM,AC impedance, cyclic voltammetry etc. examinations were used to characterize the sample comparison with the classical MnO 2 (I.C.No.1EMD,electrolytic manganese dioxide). Sample shows that the crystal styucture of the synthesized samples are mainly γ MnO 2, with average particle size in the nanometer as shown by TEM. It was found that the discharge capacity of nm MnO 2 obtained is significantly higher than that of the I.C.No.1 EMD.

Electrochemical Determination Of Trace Amouns Of Gold(Ⅲ)By Cathodic Sptripping Voltammetry Using A Carborn Paste Electroele Modified With Bacteria, Rongzong Hu, Hao Xu, Jinkun Fu, Wenyun Hu, Yanzhen Chen

Journal of Electrochemistry

An electrochemically pretreated carbon paste electrode modified with bacteria has been studied and used for determination of trace amounts of gold(Ⅲ). A detection limit of 1 ng/mL was obtained by applying cathodic stripping valtammetry. There is a linear relationship between the concentration and peak height in the range of 10～100 μg/mL. The ralative standard deviation of the response to 84.7 μg/mL Au(Ⅲ) is 3.43%.

Formation And Effect Of Tribo Cell For Fe Cr Alloy, Dongbai Sun, Tao Li, Hongying Yu, Deji Yang

Journal of Electrochemistry

The micro galvanic corrosion of 1Cr18 alloy and its effects on the triboelectrochemical behavior were investigated and analyzed in this article. It is shown that the micro galvanic corroson is due to the electrochemical inhomogenity on the surface of the alloy during the friction process. Like galvanic corrosion,the micro galvanic corrosion behaviors are greatly affected by the area ratio of unrubbed to rubbed surface.The load effects on electrochemical behavior of 1Cr18 alloy are also attributed to existence of electrochemical inhomogenity on the surface of materal.

Ac Impedance Study Of The La 0.8 Sr 0.2 Mno 3/Ysz Electrode, Shizhong Wang, Yi Zhang Yahong Jiang, Jingwang Yan, Wenzhao Li

Journal of Electrochemistry

Electrochemical reaction of oxygen on the La 0.8 Sr 0.2 MnO 3/YSZ electrode has been investigated in detail with AC impedance. The results demonstrated that the rate determining step(rds) of the reaction varies with the temperature, oxygen partial pressure and overpotential applied. At open circuit potential, the rds is the dissociative adsorption of oxygen on the LSM surface. A large number of electron holes are generated at high anodic overpotentials, while oxygen vacancies are formed at high cathodic overpotentials. The formation of the electron holes results in the electronic conduction of the YSZ electrolyte and the extension of the electrochemical …

Li Ion Intercalation Charactersitic Of Gas Coke, Zhenghua Deng, Xiaozheng Zhang, Xiaobing Ding, Mianzhong Chen, Weiguo Xie, Guoxiang Wan

Journal of Electrochemistry

A novel of carbon gas coke prepared from natural gas by thermoplasma technology has been studied. The cyclic voltametry and charge discharge test for the Li/gas coke cell demonstrated that this gas coke material has a good performance of the Li ion intercalation characteristic. X ray diffraction pattern of the gas cokeis showed that the structure of gas coke is similar to the graphite and collapsed from order to disorder during the charge discharge cycles. The gas coke electrode give rise to a new diffraction peak at a low angle after intercalating Li ion and a reversible capacity with 235 …

Photoelectrochemical Studies On Nanoporous Tio 2/Pan Film Electrode, Minsheng Liu, Yanzhong Hao, Xuebin Qiao, Maizhi Yang, Shengmin Cai

Journal of Electrochemistry

The photon to electricity conversion process of nanoporous TiO 2/PAn film electrode was studied in electrolytes with and without redox couple by using the photocurrent action spectra and potential dependence of photocurrent. It is concluded that the nanoporous TiO 2/PAn film electrode has a structure of duplex n type semiconductor layers. The band gap of PAn film is 2.88eV.The TiO 2 nanoporous film electrode modified by PAn can extend the range of optical absorption into visible and infrared region and effectively increase the photocurrent in the visible and infrared region. The photocurrent threshold shifts to>600nm and conversion efficiency of …

Prospects Of Electrochemistry, Katsumi Niki

Journal of Electrochemistry

No abstract provided.

Detection Of Intergalactic Red-Giant-Branch Stars In The Virgo Cluster, Henry C. Ferguson, Ted Von Hippel, Nial R. Tanvir

Publications

It has been suspected for nearly 50 years that clusters of galaxies contain a population of intergalactic stars, ripped from galaxies during cluster formation or when the galaxies’ orbits take them through the cluster center. Support for the existence of such a population of free-floating stars comes from measurements of the diffuse light in clusters and from recent detections of planetary nebulae with positions and/or velocities far removed from any observed cluster galaxy. 10 , 11 But estimates for the mass of the diffuse population and its distribution relative to the galaxies are still highly uncertain. Here we report the …

Putative Light Scalar Nonet, Joseph Schechter, Deirdre Black, Amir H. Fariborz, Francesco Sannino

Physics - All Scholarship

We investigate the "family" relationship of a possible scalar nonet composed of the a_0(980), the f_0(980) and the \sigma and \kappa type states found in recent treatments of \pi\pi and \pi K scattering. We work in the effective Lagrangian framework, starting from terms which yield "ideal mixing" according to Okubo's original formulation. It is noted that there is another solution corresponding to dual ideal mixing which agrees with Jaffe's picture of scalars as qq\bar q \bar q states rather than as q\bar q states. At the Lagrangian level there is no difference in the formulation of the two cases (other …

Integrating The Nation's Environmental Monitoring And Research Networks And Programs, James R. Gosz, Pete Murdoch

Long Term Ecological Research Network

An Exercise to Demonstrate the Value of Index Areas in a National Network: A Report Prepared for the Office of Science and Technology Policy (OSTP).

The Environmental Monitoring Team, a team of Federal scientists and program managers, was convened by the CENR Steering Committee and given the charge "to develop a national framework for integration and coordination of environmental monitoring and related research through collaboration and building upon existing networks and programs". Two of the recommendations for a National Environment Monitoring Framework were; 1) evaluate alternatives for selecting the number and distribution of "index areas", including stratification by ecoregion in …

Quadrilaterals Subdivided By Triangles In The Hyperbolic Plane, Dawn M. Haney, Lori T. Mckeough

Mathematical Sciences Technical Reports (MSTR)

In this paper, we consider triangle-quadrilateral pairs in the hyperbolic plane which “kaleidoscopically” tile the plane simultaneously. These tilings are called divisible tilings or subdivided tilings. We restrict our attention to the simplest case of divisible tilings, satisfying the corner condition, in which a single triangle occurs at each vertexof the quadrilateral. All possible such divisible tilings are catalogued as well as determining the minimal genus surface on which the divisible tiling exists. The tiling groups of these surfaces are also determined.

Correlation Function Formulation For The State Selected Total Reaction Probability, Sophya Garashchuk, David J. Tannor

Faculty Publications

Investigates the correlation function formulation for the state selected total reaction probability. Discussion of the wave packet propagation; Derivation of the correlation function expression for the N[sub alpha](E); Application of quantum-mechanical and Herman-Kluk propagation methods.

Semi-Automated Extraction Of Digital Objective Prism Spectra, Coryn A.L. Bailer-Jones, Ted Von Hippel, Mike Irwin

Publications

We describe a method for the extraction of spectra from high dispersion objective prism plates. Our method is a catalogue driven plate solution approach, making use of the Right Ascension and Declination coordinates for the target objects. In contrast to existing methods of photographic plate reduction, we digitize the entire plate and extract spectra off-line. This approach has the advantages that it can be applied to CCD objective prism images, and spectra can be re-extracted (or additional spectra extracted) without having to re-scan the plate. After a brief initial interactive period, the subsequent reduction procedure is completely automatic, resulting in …

Search For Selectron And Squark Production In E+P Collisions At Hera, J. Breitweg, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, R. Yoshida, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

We have searched for the production of a selectron and a squark in e+p collisions at a center-of-mass energy of 300 GeV using the ZEUS detector at HERA. The selectron and squark are sought in the direct decay into the lightest neutralino in the framework of supersymmetric extensions to the Standard Model which conserve R-parity. No evidence for the production of supersymmetric particles has been found in a data sample corresponding to 46.6 pb-1 of integrated luminosity. We express upper limits on the product of the cross section times the decay branching ratios as excluded regions in the parameter space …

The Tubular Phase Of Self-Avoiding Anisotropic Crystalline Membranes, Mark Bowick, Alex Travesset

Physics - All Scholarship

We analyze the tubular phase of self-avoiding anisotropic crystalline membranes. A careful analysis using renormalization group arguments together with symmetry requirements motivates the simplest form of the large-distance free energy describing fluctuations of tubular configurations. The non-self-avoiding limit of the model is shown to be exactly solvable. For the full self-avoiding model we compute the critical exponents using an epsilon-expansion about the upper critical embedding dimension for general internal dimension D and embedding dimension d. We then exhibit various methods for reliably extrapolating to the physical point (D=2,d=3). Our most accurate estimates are nu=0.62 for the Flory exponent and zeta=0.80 …

Applications Of Parallel I/O, Ron Oldfield, David Kotz

Computer Science Technical Reports

Scientific applications are increasingly being implemented on massively parallel supercomputers. Many of these applications have intense I/O demands, as well as massive computational requirements. This paper is essentially an annotated bibliography of papers and other sources of information about scientific applications using parallel I/O. It will be updated periodically.

The Future Of Computing: Cyberspace, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper traces trends in the technological advances of computer and communication systems and examines the promises of the Information Society: global information sharing; and, intelligent decision-support. The technological developments that will lead to the realization of Cyberspace, an information rich environment in which virtual reality capabilities couple directly to the human senses, is explored in terms of five essential components: information processing requirements; communication networks; computing devices (i.e., platforms); hardware and software user-interfaces; and, the meaningful representation of information.

Attention is drawn to the critical role played by information representation in a Cyberspace environment. The author argues …

The Round Table Model: A Web-Oriented, Agent-Based Approach To Decision-Support Applications, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Not unlike King Arthur relying on the infamous Round Table as the setting for consultation with his most trusted experts, agent-based, decision-support systems provide human decision makers with a means of solving complex problems through collaboration with collections of both human and computer-based expert agents. The Round Table Framework provides a formalized architecture together with a set of development and execution tools which can be utilized to design, develop, and execute agent-based, decision-support applications. Based on a three-tier architecture, Round Table incorporates forefront technologies including distributed-object servers, inference engines, and web-based presentation to provide a framework for collaborative, agent-based decision …

Collaborative Decision Support Systems For Facility Management, Arthur J. Chapman, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Agent-based collaborative decision support is a methodology of utilizing domain specific intelligent systems, interacting in a common environment, to partner with one or more human decision makers to reach a consensus solution to a complex problem. An example is the recently developed Collaborative Infrastructure Assessment Tool (CIAT) that provides a collaborative planning facility management tool in support of military pier and port management. This methodology is applicable to many similar dynamic facility management problems where the complexity of issues and the number of decision makers result in the need for domain specific agents, a common view of the data, and …

Mid- And Low-Latitude Prompt-Penetration Ionospheric Zonalplasma Drifts, Bela G. Fejer, L. Scherliess

Bela G. Fejer

We have used ion drift observations from the DE-2 satellite to determine the latitudinal variation and the temporal evolution of mid- and low-latitude prompt penetration zonal plasma drifts driven by magnetospheric electric fields. Our results indicate that sudden increases in convection lead to predominantly westward perturbation drifts which decrease equartorwards and have largest amplitudes in the dusk-midnight sector. The diurnal perturbation drift patterns shift to later local times with increasing storm time and decay to new quasi-equilibrium values in about 2 hours, as the ring current readjusts to the new polar cap potential. The daily and latitudinal variations and temporal …

Measured Stark Widths And Shifts Of Several Niii Sectral Lines: Temperature Dependence, Stevan Djenize, Vladimir Milosavljevic

Articles

Stark parameters (width and shift) of four doubly ionized nitrogen spectral lines, that belong to 3s-3p and 3p-3d transitions (lower multiplets), have been measured in a linear pulsed, low pressure, arc discharge in the nitrogen-oxygen and helium-nitrogen-oxygen plasmas in a (30 000 - 54 000) K electron temperature and a (0.75 10²³ - 2.8 10²³) electron density ranges. The measured values have been compared to the existing experimental and calculated data.

Orientation Of Nickelocene On Ag(100), D. L. Pugmire, C. M. Woodbridge, Marjorie Langell

Marjorie A. Langell Publications

High-resolution electron-energy-loss spectroscopy has been used to study the molecular adsorption of nickelocene, Ni(C₅H₅)₂, on Ag(100). Results indicate that at up to one monolayer coverage, nickelocene adsorbs molecularly with its axis approximately perpendicular to the surface. At very high coverages, the molecular axis is not exclusively oriented along the surface normal. This is possibly due to randomization of the metallocene orientation as multilayers are formed.

Improving Performance On Incremental Compilation Of Java Bytecodes, Tarique Kazi

Honors Capstone Projects and Theses

No abstract provided.

United States Patent: Lime Feeding Repellent, Jerrold L. Belant, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Application of lime at a rate of 500 to 1500 kg/ha to plots desired to be protected from damage by avian and mammalian feeders has been shown to be quite effective. The lime may be administered to the plots in any form. Use of either powder or slurry form is preferred.

Production Of Energy-Dependent Time Delays In Impulsive Solar Flare Hard X-Ray Emission By Short-Duration Spectral Index Variations, Ted N. La Rosa, Steven N. Shore

Faculty Articles

Cross-correlation techniques have been used recently to study the relative timing of solar flare hard X-ray emission at different energies. These studies find that for the majority of the impulsive flares observed with BATSE there is a systematic time delay of a few tens of milliseconds between low (approximate to 50 keV) and higher energy emission (approximate to 100 keV). These time delays have been interpreted as energy-dependent time-of-flight differences for electron propagation from the corona, where they are accelerated, to the chromosphere, where the bulk of the hard X-rays are emitted. We show in this paper that crosscorrelation methods …

Highly Enantioselective Hplc Separations Using The Covalently Bonded Macrocyclic Antibiotic, Ristocetin A, Chiral Stationary Phase, K. Helen Ekborg-Ott, Youbang Liu, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

The macrocyclic glycopeptide, ristocetin A, was covalently bonded to a silica gel support and evaluated as a liquid chromatographic (LC) chiral stationary phase (CSP). Over 230 racemates were resolved in either the reversed-phase mode, the normal-phase mode, or the polar-organic mode. The retention behavior and selectivity of this CSP were examined in each mode. Optimization of separations on this column is discussed. The ristocetin A CSP appeared to be complimentary to other glycopeptide CSPs (i.e., vancomycin and teicoplanin). Column stability was excellent. The CSP was not irreversibly altered when going from one mobile phase mode to another.

Method And Apparatus For Generating And Accelerating Ultrashort Electron Pulses, Donald P. Umstadter, Joon-Koo Kim, Evan Dodd

Donald Umstadter Publications

The invention provides a novel laser-plasma-based source of relativistic electrons; and a method to use laser-driven plasma waves as the basis for the source of electrons. The technique involves a combination of laser beams, which are focused in a plasma. One beam creates a wakefield plasma wave and the other beam alters the trajectory of background electrons, such that they become trapped in the plasma wave and are then accelerated to relativistic velocities, preferably in a distance less than a millimeter. In another embodiment, the second beam removes electrons from atomic ions previously generated by the first beam thereby providing …

Birds And Agroecological Relationships In Organic And Non-Organic Farmland, Nancy A. Beecher

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Water Current, Volume 30, No. 4, August 1998

Water Current Newsletter

Tent Talks, Demonstrations Highlight Sixth Annual Festival of Color, September 12
NebFacts Suggest Ways to Reduce Blue River Basins Runoff Pollution
Wetlands Tabloid Available
AWWA Research Proposals
Four Cities Hosting Third Wetlands Month Conference
UNL Seminar Series VCR Tapes Available

Micromagnetics Of Ultrathin Films With Perpendicular Magnetic Anisotropy , Ralph Skomski, H.-P. Oepen, J. Kirschner

Ralph Skomski Publications

Magnetization processes in ultra-thin transition-metal films with perpendicular magnetic anisotropy are investigated. By model calculations it is shown that nucleation in ideal films is incoherent and therefore bulk-like, whereas the truly ultra-thin limit of coherent nucleation is restricted to film patches of small cross-section areas. In ideal mono-layers, the nonzero film thickness leads to bulk-like nucleation if the lateral dimensions of the film exceed about 1 mm. This means that monolayer patches having sub-micrometer diameters cannot be regarded as ultra-thin in a micro-magnetic sense. On the other hand, the critical single-domain diameter of ultra-thin films is larger by one order …