Physical Sciences and Mathematics Commons^™

The Inhibition And Desorption Behavior Of N,N-Dipropynoxy Methyl Amine Trimethyl Phosphonate In Hydrochloride Acid, Tianbao Du, Dianzhen Cao, Jiajian Chen, Chunan Cao

Journal of Electrochemistry

The performance of inhibition mechanism and desorption behavior of the N,Ndipropynoxy methyl amine trimethyl phosphonate for iron in hydrochloride acid were investigated by means of static polarization and electrochern ical impedance spectroscopy technique.The data of the polarization curves were fitted by weak-polarization fitting technique.The results show that N,Ndipropynoxy methyl amine trimethyl phosphonate possesses high inhibiting efficiency and geometric blocking effect.It is also showed that this inhibitor obeys the Frendulich adsorption isotherm.With the increase of anodic potential,a low-frequency induce arc was observed.

Improvement Of The Anti-Interference Characteristics Of God Electrode By Using The Powder Microelectrode Technique, Chen Jian, Chuansin Cha

Journal of Electrochemistry

The electrochemical behavior of ascorbic acid(AA),uric acid(UA),L-cystein(L-Cys)and acetaminophen(APAP),i.e.the main interference to the GOD electrode,were studied at the Pt,GC and powder microelectrode. Experimental results indicated that,due to the electrochemical activity of these interference,it is difficult to eliminate their interference effects by manipulation of electrede materials or working potential of the GOD electrode. However,it was found that the limiting curtents at the KB electrode are mainly controlled by mass transfer in liquid phase,so it is only related to the geometer size of the electrode,not its rcal surface area. Therefore,it is possible to enhance significantly the signal/noise ratio of the GOD electrode by …

A Study On Electrochemical Oxidation Of Reduced Nicotinamide Coenzyme Nadh In Organic Media, Fangzu Yang, Wuhuihuang Wuhuihuang, Xushukai Xushukai, Zhoushsomin Zhoushsomin

Journal of Electrochemistry

The behaviour of electrochemical oxidation of the reduced nicotinamide coenzyme NADH on glassy carbon was studied and some kinetic parameters were measured by means of voltammometry in the N-dimethylformamide(DMF)and 1,4-dioxane media respectively. The eletrochemical oxidation of NADH shows completely irriversable both in the two solvents,and the diagnostic experiments support that the process involves a fast chemical step.The oxidation rate and the diffusion coefficient of N ADH in DMP are smaller than those in 1,4-dioxane,but the response current is more stable in DMF. The experimental results are discussed by solvent effects.

The Effect Of Additive Ce￣(4+) On The Properties Of Composite Coating Of Co-P-Ptfe, Jiaoning Tang, Ling Huang, Zhaoxong Xie, Shibing Yao, Shaoming Zhou

Journal of Electrochemistry

The effect of additive Ce4+ on the properties of composite coating of Co-P-PTFE was studied in this paper.The results show that additive Ce(4+) can change the structures and properties of Co-P-PTFE composite coating. First,the surface of the compoite coating becomes smooth and the microhardness of the composite coating increased.Secondly,additive Ce(4+) decreased the corrosion current lcorr of the composite coating in the solution of 3% NaCl and increased its property of anticorrosion.Finally additive Ce(4+) can affect preferred orientation and grain size of composite coating of Co-P-PTFE. Preferred orientation of the composite varies from(100)to(110)and the grain size decreased.

A Study On Solid Polymer Electrolyte Fuel Cell, Hongfeng Xu, Ming Han, Baolian Yi, Xinge Zhang, Shanhai Ge

Journal of Electrochemistry

Solid polymer electrolyte fuel cell(SPEFC)show promise of a high level of performance in the present fuel cell.In this paper,we report the method of SPEFC electrode preparation,and the effects of temperature,pressure and gas flow rate on the performance.

A Study Of Ruo_2-Co_3o_4-Tio_2(60)Coating On Ti-Substrate For Chlorine Gas Evolution, Liguang Yao, Mingxian Wang

Journal of Electrochemistry

The chlorine gas evolution activity,electric conductivity,service life,microstructure and surface morphology of RuO2-CO3O4-TiO2(60) coating on Ti-subetrate were studied in 0～30 m/o Co3O4 range by steady-state pelarization,x-ray diffraction,TEM and SEM methods.Active surface area of the coating was also evaluated. The in fluences of coating composition,micrortructure and surface morphology on chlorine gas evolution activity and active surface area of the coating were discussed in detail.As a result,sole rutile-type solid solution of RuO2,CO3O4 and TiO2 which showed better chlorine gas evolution activity,electric conductivity and service life was found in ca. 0～10 m/o Co3O4 range. Traditional RuO2-TiO2/Ti anedes being widely used in chlor-alkali industry could …

Time-Resolved Electron Spin Resonance Spectroscopy For In-Situ Studies Of Electrochemical Systems, Lin Zhuang, Juntao Lu

Journal of Electrochemistry

No abstract provided.

Study On The Ionic Conductivity Of Comb Polymer Electrolytes, Liming Ding

Journal of Electrochemistry

A comb polymer(CP350)with oligo-oxyethylene side chains was prepared from methyl vinyl ether/maleic anhydride copolymer.The ionic conductivity of CP350/LiAsF6 and CP350/LiPF6 complexes was studied as a function of temperature and[Li]/[EO]ratios.A equivalent circuit was given to interpret complex impedance spectra. At 25℃,the ionic conductivity maxima of the two systems are 1.38×10(-4),8.32×10(-5)S/cm respectively. The appearance of the conductivity maxima has been interpreted as being due to the effect of microviscosity on ion transport. lonic conduction displays non-Arrhenius behaviour.The temperature dependence of ionic conductivity was attributed mainly to the temperature dependence of charge carrier hopping,ion pairing and micro Brown motion of side chains.The larger …

Studies On The Charge And Discharge Reaction Of Li/Lini_(0.3)Co_(0.7)O_2 Battery, Fupjng Zhang

Journal of Electrochemistry

The charge and discharge reaction of Li/LiNi0.3Co0.7O2 battery have been studied by using CV,CT,XRD and GCP.It is shown that the discharge capacity of the cell reaches 120-140 mA·h·g(-1) in the 4.30-3.00 V in 1 mol/L LiClO4/PC electrolyte system. The discharge mechanism involve a two-step Li+ intercalation reaction. The thermodynamic data such as △G,△S,△H,of the reaction are given. Furthermore,the changes of the Dor σi of Li+ with its composition have been discussed.

An Esr Study Of Free Radicals In Electroreduction Process Of Allyl Alcohol, Jindong Zhang, Yafei Kuang, Shukun Huang, Naixian Xie

Journal of Electrochemistry

Electrochemical-ESR technique with spin trap phenyl-t-butyl nitrone(PBN)was used to study the intermediates of electroreduction of allyl alcohol at platinized platinum electrode in acidic alcohol-aqua solution. Hydrogen and allyl group and(or)propyl group radicals were identified by a hyperfine spectrum of the radical adducts,and that provided a direct evidence for the presence of these radicals in the electroreduction of allyl alcohol.

The Relationship Between Ionic Conductivity And The Structure Of The New Polymer Electrolytes, Hongze Liang, Yongxiang Song, Liming Ding, Yuchen Qi, Lixia Li, Xiabin Jing, Fusong Wang

Journal of Electrochemistry

Ionic conductivity of polymer-eutectic composed of lithium perchlorate and lithium nitrate has been studied. The effects of eutectic and polymers upon the conductivities have been discussed.The lonic conductivity depends on the eutectic properties as well as the treatment method of samples.

Kinetics And Jamming Coverage In A Random Sequential Adsorption Of Polymer Chains, Jian-Sheng Wang, Ras B. Pandey

Faculty Publications

No abstract provided.

Calibration Of A Ccd Camera And Correction Of Its Images, Armin Rest

Dissertations and Theses

Charge-Coupled-Device (CCD) cameras have opened a new world in astronomy and other related sciences with their high quantum efficiency, stability, linearity, and easy handling. Nevertheless, there is still noise in raw CCD images and even more noise is added through the image calibration process. This makes it essential to know exactly how the calibration process impacts the noise level in the image. The properties and characteristics of the calibration frames were explored. This was done for bias frames, dark frames and flat-field frames at different temperatures and for different exposure times.

At first, it seemed advantageous to scale down a …

Chemical Species Spatial Distribution And Relationship To Elevation And Snow Accumulation Rate Over The Greenland Ice Sheet, Q. Yang, Paul Andrew Mayewski, E. Linder, S. Whitlow, M. Twickler

Earth Science Faculty Scholarship

Major chemical species (Cl⁻, NO⁻₃, SO²⁻₄, Na⁺, K⁺, Mg²⁺, Ca²⁺) from 24 snowpits (sampled at a resolution of 3 cm, total 2995 samples) collected from northern, central, and southern Greenland were used for this investigation. The annual and seasonal (winter and summer) concentration of each chemical species was calculated and used to study the spatial distribution of chemical species over the central portion of the Greenland Ice Sheet. A two-sided t-distribution test (α=0.05) suggests that concentrations of major chemical species in snow do …

Strongly-Consistent, Distribution-Free Confidence Intervals For Quantiles, David Gilat, Theodore P. Hill

Research Scholars in Residence

Strongly-consistent, distribution-free confidence intervals are derived to estimate the fixed quantiles of an arbitrary unknown distribution, based on order statistics of an iid sequence from that distribution. This new method, unlike classical estimates, works for totally arbitrary (including discontinuous) distributions, and is based on recent one-sided strong laws of large numbers.

Magnetic Properties Of Tunicate Blood Cells. Ii. Ascidia Ceratodes, Kenneth Kustin, William E. Robinson, Richard B. Frankel, K. Spartalian

Physics

The magnetic properties of intact blood cells of the tunicate Ascidia ceratodes have been measured up to 50 kOe with a SQUID susceptometer. Analysis of total metal contents by plasma emission spectroscopy and V(IV) content by epr indicates that approximately 5% of the accumulated vanadium is +4 vanadyl ion. Measured values of the magnetic moment M_P at different values of the applied magnetic field H over the temperature range T = 2–100 K depend on the magnitude of the field indicating magnetic anisotropy of the ground state. The slope of the M_P vs. H/T curve at …

Suppressing Curvature Fluctuations In Dynamical Triangulations, Simon Catterall, Mark Bowick, G. Thorleifssona

Physics - All Scholarship

We study numerically the dynamical triangulation formulation of two-dimensional quantum gravity using a restricted class of triangulation, so-called minimal triangulations, in which only vertices of coordination number 5, 6, and 7 are allowed. A real-space RG analysis shows that for pure gravity (central charge c = 0) this restriction does not affect the critical behavior of the model. Furthermore, we show that the critical behavior of an Ising model coupled to minimal dynamical triangulations (c = 1/2) is still governed by the KPZ-exponents.

Blocking Of Dynamical Triangulations With Matter, Simon Catterall, E. Gregory, G. Thorleifsson

Physics - All Scholarship

We use the recently proposed node decimation algorithm for blocking dynamical geometries to investigate a class of models, with central charge greater than unity, coupled to 2D gravity. We demonstrate that the blocking preserves the fractal structure of the surfaces.

Koala: An Object-Agent Design System, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper describes KOALA, a design system with primary focus on the predesign stage of architectural design. KOALA combines object-agent technology with high level representation to form a partnership between the human designer and the computer-based design environment. A diverse taxonomy of agents including Domain agents. Space agents, and Monitor agents work in a collaborative fashion to provide the human designer with expert evaluation and assistance in developing a design solution. Spaces, in their roles as agents attempt to formulate various design solutions based on individual perspectives through negotiation with other agents. The result is a highly interactive design environment …

Managing Multiple Information Sources Through Ontologies: Relationship Between Vocabulary Heterogeneity And Loss Of Information, Eduardo Mena, Vipul Kashyap, Arantza Illarramendi, Amit P. Sheth

Kno.e.sis Publications

The ability to deal with a huge number of independent and heterogeneous repositories is the most critical problem in Global Information Systems. One approach to enable efficient query processing is by utilizing semantic descriptions (organized as ontologies) of such repositories whenever available.

In this context semantic relationships among ontologies can be used Query Processors. Three kind of relationships are considered: synonyms and hypernyms. Using synonyms the semantic of the query is preserved; however, when synonyms are not available and hypernyms or hyponyms are used there exists some loss of information that must be measured.

Some Applications Of Sophisticated Mathematics To Randomized Computing, Ronald I. Greenberg

Computer Science: Faculty Publications and Other Works

No abstract provided.

The Flat Phase Of Fixed-Connectivity Membranes, Simon Catterall, Mark Bowick, Marco Falcioni, G. Thorleifsson, Konstantinos N. Anagnostopoulos

Physics - All Scholarship

The statistical mechanics of flexible two-dimensional surfaces (membranes) appears in a wide variety of physical settings. In this talk we discuss the simplest case of fixed-connectivity surfaces. We first review the current theoretical understanding of the remarkable flat phase of such membranes. We then summarize the results of a recent large scale Monte Carlo simulation of the simplest conceivable discrete realization of this system \cite{BCFTA}. We verify the existence of long-range order, determine the associated critical exponents of the flat phase and compare the results to the predictions of various theoretical models.

Simplicial Gravity In Dimension Greater Than Two, Simon Catterall, G. Thorleifsson, John B. Kogut, R. Renken

Physics - All Scholarship

We consider two issues in the DT model of quantum gravity. First, it is shown that the triangulation space for D>3 is dominated by triangulations containing a single singular (D-3)-simplex composed of vertices with divergent dual volumes. Second we study the ergodicity of current simulation algorithms. Results from runs conducted close to the phase transition of the four-dimensional theory are shown. We see no strong indications of ergodicity br eaking in the simulation and our data support recent claims that the transition is most probably first order. Furthermore, we show that the critical properties of the system are determined …

Comment On "Moving Glass Phase Of Driven Lattices", Leon Balents, M. Cristina Marchetti, Leo Radzihovsky

Physics - All Scholarship

We consider a periodic lattice rapidly driven through a quenched random potential as a model of a moving Abrikosov lattice. In addition to the transverse phonon displacements u_y, we consider the displacements u_x along the direction of motion, which were assumed to be small in earlier treatments. We show that these displacements are in fact divergent even on large length scales and therefore lead to a breakdown of the elastic model along the direction of motion. We propose that the resulting phase is a moving "smectic" with translational order that is quasi-long-range transverse and liquid-like parallel to the direction of …

A Prototype National Drought Alert Strategic Information System For Australia, Ken D. Brook, John O. Carter

Drought Network News (1994-2001)

Defining and categorizing drought in a quantitative and scientific manner are important national issues for Australian state and Commonwealth governments, landholders, and agribusiness. The challenge for modelers of Australia’s grasslands is to integrate biological models, geographic information systems (GIS), satellite imagery, economics, climatology, and visual high-performance computing into an Internet-deliverable application that can provide easily understood monitoring and prediction advice in near real-time— a national drought alert strategic information system.

Although NOAA satellite-derived imagery has been somewhat useful in the broad-scale spatial assessment of green cover, especially the spatial response of vegetation to rainfall events (Smith, 1994; Dudgeon et al., …

Drought Continues In Hungary In 1995, Attila Bussay, Csaba Szinell

Drought Network News (1994-2001)

In 1995, Hungary again suffered from serious drought. Fortunately, drought has not extended over the whole country. It is primarily centered in the southeast, a plain area with significant agricultural production.

Meteorological conditions have been the most important factors in the evolution of the drought. The start of 1995 was not ideal; dry conditions during 1994 resulted in poor soil moisture at the beginning of the season. In Figure 1, the water shortage is indicated using the Palmer Drought Severity Index (PDSI), revealing the extraordinarily dry winter conditions in the east.

Propogation Of Juniperus For Conservation Plantings In The Great Plains, Scott Allen Lee

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

No abstract provided.

The Biology Of Alewife Alosa Pseudoharengus In Lake Ogallala, Nebraska, Eric A. Laux

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

No abstract provided.

Water Current, Volume 28, No. 4, August 1996

Water Current Newsletter

Four-Year Study Finds NU Recommendations Dependable
From the Director: Nebraska Grants Success
Fluoridation Makes Comeback in Nebraska Communities
Installation of Water Garden New to Festival

Uniqueness For A Boundary Identification Problem In Thermal Imaging, Kurt M. Bryan, Lester F. Caudill

Mathematical Sciences Technical Reports (MSTR)

An inverse problem for a parabolic initial-boundary value problem is considered. The goal is to determine an unknown portion of the boundary of a region in Rⁿ from measurements of Dirichlet data on a known portion of the boundary. It is shown that under reasonable hypotheses uniqueness results hold.