Physical Sciences and Mathematics Commons^™

Arkansas Soil Fertility Studies 1998, Wayne Sabbe

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts also be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies contained within will allow producers to compare their practices with the university’s research efforts. Additionally, soil test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Improving Cape Canaveral's Next-Day Thunderstorm Forecasting Using A Meso-Eta Model-Based Index, John C. Crane

Theses and Dissertations

Reliable thunderstorm forecasts are essential to safety and resource protection at Cape Canaveral. Current methods of forecasting day-2 thunderstorms provide little improvement over forecasting by persistence alone and are therefore in need of replacement. This research focused on using the mesoscale eta model to develop an index for improved forecasting of day-2 thunderstorms. Logistic regression techniques were used to regress the occurrence of a thunderstorm at Cape Canaveral against day-2 forecast variables output, or derived, from the mesoscale eta model. Accuracy and bias scores were calculated for the forecasts made by the regression equations, and the forecast results were compared …

Mirroring Behavior Of Partial Photodetachment And Photoionization Cross Sections In The Neighborhood Of A Resonance, Chien-Nan Liu, Anthony F. Starace

Anthony F. Starace Publications

Partial photodetachment and photoionization cross sections corresponding to highly excited residual atoms or ions are shown analytically to mirror one another in the neighborhood of a resonance. More precisely, any two groupings of partial cross sections are shown here to have components whose variations with energy near a resonance are equal in magnitude and opposite in direction. This work extends an analysis of Starace [Phys. Rev. A 16, 231 (1977)] for the behavior of partial cross sections near a resonance to the case when the ρ2 parameter of Fano and Cooper [Phys. Rev. 137, A1364 (1965)] tends to zero.

Land Evaluation Standards For Land Resource Mapping : Guidelines For Assessing Land Qualities And Determining Land Capability In South-West Western Australia, Dennis Van Gool, Geoff Allan Moore

Resource management technical reports

Updated by report 298, van Gool, D, Tille, P J, and Moore, G A. (2005)
This report provides a standard method for attributing and evaluating digital land resource maps in Western Australia so that strategic decisions about the management, development and consevation of land resources can be based on the best information available. The standards update the generic methodology described by Wells and King (1989) which have been used routinely for the assessment of land resources in catchment and land use planning in Western Australia.

Resource Scheduling In A High-Performance Multimedia Server, Hwee Hwa Pang, Bobby Jose, M. S. Krishnan

Research Collection School Of Computing and Information Systems

Supporting continuous media data-such as video and audio-imposes stringent demands on the retrieval performance of a multimedia server. In this paper, we propose and evaluate a set of data placement and retrieval algorithms to exploit the full capacity of the disks in a multimedia server. The data placement algorithm declusters every object over all of the disks in the server-using a time-based declustering unit-with the aim of balancing the disk load. As for runtime retrieval, the quintessence of the algorithm is to give each disk advance notification of the blocks that have to be fetched in the impending time periods, …

The Window Distribution Of Idealized Tcp Congestion Avoidance With Variable Packet Loss, Archan Misra, Teunis J. Ott

Research Collection School Of Computing and Information Systems

This paper analyzes the stationary behavior of the TCP congestion window performing ideal congestion avoidance when the packet loss probability is not constant, but varies as a function of the window size. By neglecting the detailed window behavior during fast recovery, we are able to derive a Markov process that is then approximated by a continuous-time, continuous state space process. The stationary distribution of this process is analyzed and derived numerically and then extrapolated to obtain the stationary distribution of the TCP window. This numerical analysis enables us to predict the behavior of the TCP congestion window when interacting with …

Tennis, Geometric Progression, Probability And Basketball, Mostafa Ghandehari

Mathematics Technical Papers

The following problem about a tennis match is well—known. See Halmos [1, 2]. Consider 2n tennis players playing a single elimination match. Ask the question: what are the number of games played? The answer can be obtained in two ways. First using the geometric progression 2n-1 + 2n-2 + • • • -2+1 we find that the answer is 2n — 1. We can also explain the answer as follows: for each game played there is a loser. Thus the total number of games played is equal to the number of losers. Since there is only one winner the total …

Status Of The Major Oyster Diseases In Virginia 1998 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.

Three Dimensional Hydrodynamic-Sedimentation Modeling Study : Hampton Roads Crossing, Lower James River, Virginia, John D. Boon, Harry V. Wang, S. C. Kim, Albert Y. Kuo, G. M. Sisson

Reports

A three-dimensional hydrodynamic-sedimentation computer model, HYSED-3D, was used to evaluate the effect of bridge-tunnel infrastructure for a proposed highway crossing of Hampton Roads on the physical characteristics (tides, currents, circulation, salinity, and sedimentation) of the James River estuary in Virginia. Model-represented infrastructure included tunnel islands and bridges on pilings connecting the islands to interstate highways in Newport News, Hampton, Norfolk, and Portsmouth, Virginia. Combinations of these elements occur in each of three proposed crossing routes designated Alternative 1 (Hampton-Norfolk), Alternative 2 (Hampton-Norfolk, Norfolk-Portsmouth), and Alternative 9 (Newport News-Portsmouth-Norfolk). Simulation comparisons were made between the existing waterways and infrastructure in Hampton …

Research And Implementation Of Integrated Concurrent Software Development Environment Based On Object-Oriented Petri Nets, Jinzhong Niu

Publications and Research

While network technologies and environments get more and more popular, the demand for concurrent systems becomes stronger and stronger. But the characteristics of concurrency make it difficult to develop them.

This dissertation combines Object-Oriented technology and Petri Nets theory, and put forth OOPN (OO Petri Nets) model to describe concurrent systems. Based on the research of conventional development methods of concurrent software, this article advances a new one, which integrates specification, validation and auto-generating codes. Accordingly, an integrated development environment for concurrent software, i.e., OOPN-IDE, comes into being, which mainly includes the following four tools: the concurrent system modeling tool …

Electrochemical Surface Characterization Of Titanium Alloy(Ti_6al_4v)), Jianzhong Chen, Qingliang Gao, Zhongyi Wang, Wenjing Xue

Journal of Electrochemistry

With its low density and high strength ratio, titanium alloy(Ti_6Al_4V) has become one of the most important materials both in the fields of aerospace and biomedical assays. Recently, titanium alloy was used as the implantation materials in human body because of its biocompatibility. The elecrochemical impedance techniques were then used to investigate the corrosion behavior of this material in hydrochloride and sulfuric acid solutions. A comparison between impedance spectra and anodic polarization over the correlated range of applied voltage confirms that AC impedance data can be used as a powerful tool for surface characterization of titanium alloy.

Some Effects Of Co On The Electrochromic Properties Of Nio Xh Y Film, Xiaoyan Cao, Wenhu Zhang, Huatang Yuan, Wanlin Zhang, Yinnong Lin, Zuoxiang Zhang Yunshi Zhou

Journal of Electrochemistry

Some effects of Co addition upon the electrochromic characteristics of a nic_kel hydroxide film were studied. The films were electrodeposited on both polished Ni plate and conductive ITO glass. The electrochemical behaviors were investigated using the film on Ni plate by linear potential sweep, a.c. impedance, and anodic polarization curves for OER(oxygen evolution reaction). It was found that Co can lower the working voltage and raise the oxygen overpotential, but has little effect on the reaction kinetics. It was also found that the Co can improve the optical properties of the electrochromic film.

Study On The Mechanism Of Ni/Zro 2 Composite Electrodeposition, Qunjia Peng, Daobin Mu, Jusheng Ma, Xiangyun Tang

Journal of Electrochemistry

The effects of cathodic current density and amount of particle dispersion in solution on the codeposition of Ni/ZrO 2 composite in Watts bath were studied, and the machanism of the composite electrodeposition was investigated.The study shows that the composite electrodeposition is controlled by the transfer of particles to the cathode when the dispersion amount is small, causing the decrease of the codeposition with the increase of current density. With large amount dispersion,the composite electrodeposition is first controlled by the strong adsorption of particles on the cathode at low current density, resulting in the increase of the codeposition with the increase …

Kinetic Study Of Electrooxidation Of Benzene, Xinsheng Ding Ping Zhang, Yingchun Dai, Weikang Yuan

Journal of Electrochemistry

A reaction kinetic study for electrochemical oxidation of benzene was performed on a PbO 2 rotating disk electrode in 1 mol/L H 2SO 4 aqueous solution. The reaction orders, the activation energies and transfer coefficient were measured, and the kinetic expression was obtained.

Pitting Corrosion Of Ni_Based Alloy In Thiosulfate_Ion Containing Chloride Solutions, Yungfa Lee, Tingyu Wang, Wenta Tsai

Journal of Electrochemistry

The effect of thiosulfate ion on the pitting corrosion behavior of Ni_Based Alloy 690 in chloride solution was investigated.In plain sodium thiosulfate solution,Alloy 690 was immune to pitting corrosion. However, the addition of low concentration of sodium thiosulfate can enhance the initiation of pitting corrosion of Alloy 690. Nevertheless, inhibition of pitting corrosion was observed at high concentration of addition.

Synthesis And Application Of Polymeric Corrosion Inhibitor For Reinforced Concrete, Weiwei Lin, Shengxian Wang, Jianqing Zhang

Journal of Electrochemistry

A new polymer E Twas synthesized and used as a corrosion inhibitor for reinforced concrete. The inhibitive behavior and mechanism were studied with linear polarization ,Tafel polarization,EIS and XPS method in simulated pore solution system with concrete samples.The result showed that the polymer was a mixing type inhibitor. A 1% dosage was sufficient to imhibit the corrosion of steel in simulated pore solution system. The salt endurance was enhanced from 0.02 mol/L to 0.10 mol/L.The result also showed the good synergetic effect of NaNO 2,especially in low NaNO 2 concentration.The EIS showed that E_T has dual function on reinforced concrete,i.e.,densifying …

Structural And Electrochemical Studies On Todorokite/Vernadite As Cathodes For Rechargeable Lithium Ion Batteries, Wei Chu, Deyao Liu, Jinkua You, Yong Yang, Zugeng Lin

Journal of Electrochemistry

XRD,TEM,ICP,low scan_rate CV and charge/discharge tests were carried out for the studies on the structural and electrochemical behavior of a prepared 3 V manganese oxide cathode for rechargeable lithium ion batteries.XRD analysis revealed that the cathode sample is mainly composed of tunneled Todorokite and layered Vernadite.TEM investigation confirmed that the morphology of the sample is a laminated construction with approximate 10nm layer space.The reversibility of Li + removal/intercalation and structural stability of this sample framework to lithium insertion are good in CV and charge/discharge tests. The discharge capacities were found to be about 129mAh/g obtained on first 30 cycles and …

Studies Of Electrochemical Characteristics Of Pasted Nickel Hydroxide Electrode With Surface Deposited Cobalt, Xianyou Wang, Yunshi Zhang, Jie Yan, Zheng Zhu, Huatang Yuan, Deying Song

Journal of Electrochemistry

The surface of the spherical nickel hydroxide particles used as an active material in pasted nickel electrodes is surface_deposited with cobalt. This paper investigated the effects of the amount of cobalt deposit on the characteristics of nickel hydroxide electrode. The performances of the electrode, such as discharge capacity, utilization of active material and reversibility of Ni(OH) 2/NiOOH redox reaction, were studied by comparing the charging/discharging curves and cyclic voltammograms. The mechanism of action of cobalt deposits has been described in terms of the electrochemical impedance spectroscopy of nickel hydroxide electrode.

Study On Ionic Conductivity Of A Novel Solid State Electrolyte, Yingxin Zhao, Changyan Liu

Journal of Electrochemistry

Various novel predominantly lithium_ion_conducting solid state electrolytes were described, which had high conductivity at room temperature. It comprised low_melting_point eutectic lithium salts in which a small amount of an single ion polyeletrolyte poly(lithium acrylate) was dissolved to rubberize them. The effects of the eutectic and polymer features upon the ionic conductivity were discussed.

A New Cell Structure For Proton Exchange Membrane Fuel Cell, Ming Han, Hongfeng Xu, Baolian Yi

Journal of Electrochemistry

Separating the functions of current collection and gas flow distribution and then to design two separate elements to achieve the desired performance characteristics,a nonconventional cell structure for proton exchange membrane fuel cells bave been developed.The current collector is achieved using a thin stain steel sheet,the gas flow distribution is achieved using a carbon paper that has the desired chemical durabiliy when in contact with the proton exchange membrane. Combining these two separate elements into a single divice yields a bifunctional device that performs as a bipolar separator plate. The advantages of this alternative appproach to making biplar plates are that …

Some Studies On Shape Of Dot Patterns., Anirban Ray Chaudhuri Dr.

Doctoral Theses

The important visual characteristics of an object are shape, size, color, brightness, contrast and texture. Of them, shape is a multidimensional concept that is difficult to define. It takes different meanings in different contexts. We try to explain it in terms of their attributes like elongation, roundness, and symmetry: although these terms do not capture the complete notion of shape.Perhaps Gestalt theory Koffka 351 is the first attempt to study the principles of visual perception in a systematic manner. The central concept of this theory is Gestalt' which means form or configuration. In this theory form is examined from physical. …

Studies Of Supply Responses In Indian Agriculture: Some Models For Planning Rational Food Supply., Nilabja Ghosh Dr.

Doctoral Theses

This thesis deals with food supply in a less developed country.In a world where social awareness together with technical progress is offering advances in all spheres of life, the persisting presence of hunger and malnutrition in any corner of the earth casts a shadow on all human achievements. It is said that over 800 million human beings in this world are suffering from hunger and a great majority of them live in Asia. Food problem has many dimensions (Timmer et al, 1983), but the solution lies mostly in adequate supply of foodgrains and proper distribution of the same. Any shortfall …

Electrodeposition Of Neodymium_Iron Group Alloy Films In( P _Ch 3c 6h 4so 3) 3nd+Dmf System, Peng Liu, Yexiang Tong, Qiqin Yang, Yansheng Yang

Journal of Electrochemistry

Neodymium p _toluenesulfonate was prepared and applied to the electrodepositon of neodymium_iron group alloy films. This salt has high solubility in DMF and can be dehydrated easily. Cyclic voltammograms of Pt electrode in ( p _CH 3C 6H 4SO 3) 3Nd+MCl 2(M=Fe,Co,Ni)+DMF indicated that the neodymiun_iron group alloys can be elcetrodeposited from this medium, the Nd_Fe,Nd_Co and Nd_Ni films were obtained by electrolysis at constant potential. The Nd_Fe,Nd_Co and Nd_Ni films are amorphous in which the rare earth contents are in the range of 15 at%～60 at% as analyzed by XRD and EDS. The Nd content in the deposited film …

Oxidation Mechanism Of Hypophosphite, Dongbai Sun, Ying Jin, Hongying Yu, Dejun Yang

Journal of Electrochemistry

There exist two oxidation current peaks on the anodic polarization curve between -0.7 V and 0 V(SCE) in Na_hypophosphite solution. Peak Ⅰ (-0.55 V, SCE) , which represents the oxidation process from H 2PO - 2 to H 2PO - 3, has been studied previously. Peak Ⅱ, which is located at the potential about -0.4 V(SCE), is investigated emphatically in this paper. The results show that, peak Ⅰ and Ⅱ are corresponding to two successive steps in oxidation process of H 2PO - 2, i.e. peak Ⅱ corresponds to the oxidation process of adsorped (HPO 2) ads , an intermediate …

Study On Steel Corrosion In Simulated Biofilm Environment In Seawater, Qingfei Wang, Jing Sui, Runxi Su, Deying Kong, Shizhe Song

Journal of Electrochemistry

Biofilm is one of the main factors that influence metal corrosion in seawater environment. According to the structure and property of biofilm, a natural biopolymeric gel,calcium alginate(an extracellular biopolymer containing carboxylate functional groups) can deposite on metal surfaces to form films. Corrosion behavior of alloyed steel E 2, 10CrMoAl and 18_8 stainless steel were studied in simulated biofilm environment by various electrochemical methods,including measurements of the corrosion potential,polarization curves,galvanic current and electrochemical impedance.The results show that such an approach is informative to reveal “how” and “to what extent” biofilm can influence the metal corrosion process.

Study Of Electrochemistry Of Tetrasulphonated Phthalocyanine Zinc In Aqueous And Nonaqueous Solvents, Ersheng Liu, Yiqun Wu, Jianhui Yang, Liying Huang, Jundong Wang, Suling Yang, Naisheng Chen, Jinling Huang

Journal of Electrochemistry

The voltammetry of Tetra_sulphonated phthalocyanine Zn(TSPcZn)in DMSO and DMF solution has been examined and compared with those obtained in aqueous solution.The results showed that three pairs of redox peaks were appear in non_aqueous solvents,exhibiting three quasi_reversible phthalocyanine ligand based one_electron transfers,while in aqueous solution did no quasi_reversible behaviour was observed. The photoelectrochemical effect of light on TSPcZn redox reactions were also discussed.

Time-Space Harmonic Polynomials For Stochastic Processes., Arindam Sengupta Dr.

Doctoral Theses

The sequence of polynomials of a single variable known as the Hermite polynomialshala) = ), k21, (-1)* ha(z) =has many close links with the Normal distribution. Their association goes very doep, and extends to several connections bet ween the two-variable Hermite polynomialsHll, 2) = the(z/t), . k21.and the prime example of Gaussian processes, that is Brownian motion, as well. Much of this connection stems from what we term the time-space harmonic property of these polynomials for the Brownian motion process. An exact definition of this property follows later. A natural question that arises is, for stochastic processes in general, when …

Study Of Localized Corrosion Of Metals By Using The Electrochemical Techniques With Spatial Resolution, Changjian Lin, Xiangdong Zhuo, Zude Feng, Ronggui Du, Zhaowu Tian

Journal of Electrochemistry

The electrochemical inhomogeneities at interface of metal/solution play an important and often controlling role in localized corrosion of metals.The traditional electrochemical techniques involving potential,current density or ac impedance measurements over bulk specimens can only provide average and general information of the interface. Thus, the development of in situ imaging techniques is essential for further characterizing electrochemical inhomogeneities at the metal/solution interface of localized corrosion system.The electrochemical techniques with spatial resolution,including scanning single micro electrode,scanning double micro electrodse and scanning micro chemical probes are reviewed.The effects of electrochemical inhomogeneities on the corrosion behavior,and the mechanism fot various localized corrosion of metals …

Effect Of Stress On Electrochemical Behaviour Of Various Thermal History Zones And Different Phase Structures On The Weldment For Low Alloy Steel, Yinshun Wu, Deyu Liu, Bei Cao, Fengli Wang, Zhi Fang, Lin Zhang, Zhengrong Zhang, Hai Yang

Journal of Electrochemistry

The electrochemical behaviour of various thermal history zones on the weldment for steel 16Mn and also of the ferrite,pearlite in various zones was measured by use of a self-developed measuring technique for investigating the electrochemicl behaviour of single and mixed phase structures in metal materials.Especially the effect of stress on this electrochemical behaviour was investigated.The results showed that by comparison with non-stress condition,the free corrosion potential of the various thermal history zones and of the ferrite,pearlite under stress condition was shifted in negative direction,correspondingly their free corrosion current density was increased,the free corrosion potential difference between ferrite and pearlite was …

Electrohydrodimerization Of Fumarodinitrile On Liquid Gallium Electrode, He Wei, Huang Ying

Journal of Electrochemistry

Electrohydrodimerization(EHD) of fumarodinitrile on liquid gallium electrode can take place not only in hydrotropic solution of tetraethylammonium p_toluenesulphonate(TEA_PTS), but also in aqueous solution containing low concentration of strong surfactants, such as TritonX_100. In solution without organic surfactant, FDN yields a single two_electron reduction wave corresponding to the formation of a saturated monomer called as butanedinitrile. If some TEA_PTS or TritonX_100 is added into the solution, the original two_electron wave is splitted into two continuous single_electron reduction wave and corresponding EHD of fumarodinitrile is obtained.