Digital Commons Network^™

Censusing And Modeling The Dynamics Of A Population Of Eastern Hemlock (Tsuga Canadensis L.) Using Remote Sensing, W. Robert Lamar

Graduate Theses, Dissertations, and Problem Reports (ETD)

A population of eastern hemlock (Tsuga canadensis L.) was censused from the ground using traditional field methods and from the air using large scale, high-resolution, aerial imagery in the early spring of 1997, 1998 and 1999. A manual crown survey map of the population, prepared from aerial imagery, was compared to a traditional field census. Over 60% of the individuals measured on the ground were not detected in the aerial census. Tree size, crown density and crown position all played roles in determining a crown's visibility from the air. Nearly all large, upper canopy hemlocks were visible in the aerial …

Designing A Scalable Dynamic Load -Balancing Algorithm For Pipelined Single Program Multiple Data Applications On A Non-Dedicated Heterogeneous Network Of Workstations, Ashraf Osman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Dynamic load balancing strategies have been shown to be the most critical part of an efficient implementation of various applications on large distributed computing systems. The need for dynamic load balancing strategies increases when the underlying hardware is a non-dedicated heterogeneous network of workstations (HNOW). This research focuses on the single program multiple data (SPMD) programming model as it has been extensively used in parallel programming for its simplicity and scalability in terms of computational power and memory size.;This dissertation formally defines and addresses the problem of designing a scalable dynamic load-balancing algorithm for pipelined SPMD applications on non-dedicated HNOW. …

Investigation Of Initiation Of Reverse Transcription In Retroviruses Using Vectors With Two Primer -Binding Sites, Yegor A. Voronin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Initiation of reverse transcription in retroviruses occurs on a specific place in viral genome, called primer-binding site (PBS). Cellular tRNA is annealed to the complementary PBS and is used as a primer. We constructed murine leukemia virus (MLV)-based vectors containing two PBSs, one in normal position and another in the middle of the vector. Green fluorescence protein (GFP) gene was inserted between the two PBSs. The internal PBS was derived from a spleen necrosis virus (SNV), which uses the same tRNA-Pro as a primer. We have shown that the internal PBS was functional for initiation of reverse transcription. Replication of …

Numerical Analysis Of Source-Water Dynamics For Stream-Bounded Alluvial Aquifers, Sarah E. Webb

Graduate Theses, Dissertations, and Problem Reports (ETD)

Alluvial aquifers bounded by streams are water supply sources for numerous communities in the Ohio Valley, West Virginia. Groundwater flow models are tools for estimation of source areas, however, existing analytical solutions apply only in settings involving a single stream boundary. A series of numerical experiments was devised for wells near multiple surface sources examining the controlling aspects of well-location and boundary condition interaction on source areas. Local-scale models were constructed representing an alluvial aquifer bounded by a tributary intersecting a large river. Aquifer behavior was examined in response to variations in pumping well location and tributary gradient. Flow within …

Model Predictive Control Design For Load Frequency Control Problem, Nedzad Atic

Graduate Theses, Dissertations, and Problem Reports (ETD)

Load Frequency Control (LFC) is a mechanism by which power generation and power demand are balanced.;Model Predictive Control (MPC) has been widely accepted as a viable control strategy in the process industry. It is a model based control strategy where an optimization procedure is performed in every sampling interval over a prediction horizon, yielding an optimal control action. The optimization criterion, or objective function, is chosen in such a way as to satisfy the controlled system dynamics and constraints, penalize system output deviation from the desired trajectory, and minimize control efforts. Furthermore, a possibility to incorporate economic objectives into the …

Measurement Of High-Q2 Charged Current Cross Sections In E +P Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan

Faculty Publications

Cross sections for e+p charged current deep inelastic scattering at a centre-of-mass energy of 318 GeV have been determined with an integrated luminosity of 60.9 pb-1 collected with the ZEUS detector at HERA. The differential cross sections dσ/dQ2, dσ/dx and dσ/dy for Q2 > 200 GeV2 are presented. In addition, d2σ/dxdQ2 has been measured in the kinematic range 280 GeV2 < Q2 < 17 000 GeV2 and 0.008 < x < 0.42. The predictions of the Standard Model agree well with the measured cross sections. The mass of the W boson propagator is determined to be MW = 78.9 ± 2.0 (stat.) ± 1.8 (syst.) -1.8+2.0 (PDF) GeV from a fit to dσ/dQ2. The chiral structure of the Standard Model is also investigated in terms of the (1-y)2 dependence of the double-differential cross section. The structure-function F2CC has been extracted by combining the measurements presented here with previous ZEUS results from e-p scattering, extending the measurement obtained in a neutrino-nucleus scattering experiment to a significantly higher Q2 region.

Comparing Math Self-Efficacy In Middle School Girls, Anagloria Rodriguez

Graduate Theses, Dissertations, and Problem Reports (ETD)

There have been no previous studies in the self-efficacy or single-sex schools literature that have looked at the possible relationship between self-efficacy expectations and type of school. This study compared mathematics self-efficacy of sixth, seventh, and eighth grade girls in a single-sex and a co-educational school. Four measures, including a personal background questionnaire, were used to collect data. Results showed a correlation for type of school and importance of mathematics. Contrary to assumptions made by the researcher, girls in the co-educational school scored consistently higher on all measures used. The results of this research suggest that it will take more …

Data Analysis In The Antes System, Yavuz Tor

Theses and Dissertations - UTB/UTPA

Acanthosis nigricans is a skin condition that can be used as an indicator for the risk of developing type 2 diabetes in the future. Border Health Office, in University of Texas - Pan American, organizes screenings in schools for acanthosis nigricans. Screening results are, then, collected and evaluated in the Border Health Office. The ANTES System is a computer system that stores and manages the data collected in those screenings.

This study is on the analysis of those collected data to track the progress of data entry, to evaluate the progress on obesity and related problems, and to discover the …

Visualization Of Internet Web Pages Based On Authority And Word Frequency, David Navarro

Theses and Dissertations - UTB/UTPA

The growth, accessibility, and integration of the World Wide Web with contemporary information utilization provides a rich domain in which to explore information retrieval systems. One approach in the evolution of retrieval systems couples successful and long-standing techniques of information retrieval with new techniques, such as visualization. The system developed and reported in this thesis takes this approach. It builds upon well-known techniques of information retrieval including stemming, keyword matching, and cosine similarity. It also incorporates the new and relatively successful hubs and authority approach, which describes Web documents by their reference by other documents. Finally, it develops a new …

Claus/Claws: A Journey Through Leonardland's Multivalent Meanings, Chris Leonard

Theses and Dissertations - UTB/UTPA

This exhibition paper presents the linkage of apparently unrelated topic and content. This arduous task is accomplished through an exploration of opposites and an overall presentation in the form of family fun or domestic distress disguised within personal world and the overall umbrella of homonyms: Claus (as in Santa) and Claws (as in cat). The work presented is a view of Leonardland, an intensely personal vision of my family and our history melded into a proposed future as seen through a wild conglomeration of seemingly dissimilar visions comprising the eclectic cultural mix that is our life on this geographic and …

Analysis Of Articles Published In Eight Selected Higher Education Journals On Selected Variables To Reveal Scholarly Development Of The Discipline, Kathy Brock Enger

Theses and Dissertations

The development of a discipline is reflected in its literature. Higher education is a fairly young discipline, as shown by the large amount of its literature beginning in the 1970s or later. Studying the literature of a discipline reveals various aspects of its development, and gives those engaged in its development an assessment of what is being done and who is doing it at a particular point in time. Using bibliometrics, or the literature as data, this dissertation examined articles in eight selected higher education scholarly journals in 1995 and 2000 to determine characteristics of the authors producing higher education …

Survey Of Health Effects Among Residents Adjacent To A National Priority List Site In Ssouthwest Virginia., Danette Haywood

Electronic Theses and Dissertations

The Saltville Waste Disposal Site is a National Priority List site used during the 77- year operation (1895–1972) of an electrolytic chlorine and caustic soda plant. A cross-sectional study was conducted to determine disease prevalence among Saltville Medical Center (SMC) patients. Diseases associated with chronic exposures to mercury, arsenic, and lead were reviewed in patient records and these data were analyzed. Ratios of illness observed at the SMC were compared to health studies of similar environmental exposures and disease prevalence among residents of neighboring communities. Prevalence ratios were calculated for residents and non-residents of Saltville who were SMC patients. Saltville …

A Historical Review And Financial Analysis Of Higher Education Funding In Tennessee., Claire Sauls Stinson

Electronic Theses and Dissertations

This was a study of the development of an objective funding method for public higher education institutions in Tennessee. The review covers the history of higher education funding from the early 1800s through the beginning of the twenty-first century with emphasis on the early 1960s through the year 2000. The study describes and analyzes the efforts made in Tennessee to provide adequate and equitable funding to public higher education institutions.

Minutes of meetings of the Tennessee Higher Education Commission, reports on studies commissioned by state officials, accountability reports prepared by the Tennessee Higher Education Commission, the Tennessee Board of Regents …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Fourth Quarterly Report 09/01/2003-11/30/2003, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Poisonous Snakes And Snakebite In Nebraska, Ron J. Johnson

Other Publications in Wildlife Management

Recognizing Poisonous Snakes Prairie rattlesnake Timber rattlesnake Western massasauga Copperhead THE "2-3-4" OF SNAKEBITE Avoiding Poisonous Snakes - The "2" What SHOULD be done in case of Poisonous Snakebite - The "3" What SHOULD NOT Be Done - The "4" Should You Kill Poisonous Snakes on Sight? IN CASE OF POISONOUS SNAKEBITE

Laser-Energy Transfer And Enhancement Of Plasma Waves And Electron Beams By Interfering High-Intensity Laser Pulses, P. Zhang, N. Saleh, Shouyuan Chen, Z.M. Sheng, Donald P. Umstadter

Donald Umstadter Publications

The effects of interference due to crossed laser beams were studied experimentally in the high-intensity regime. Two ultrashort (400 fs), high-intensity (4×10¹⁷ and 1.6×10¹⁸ W/cm²) and1µm wavelength laser pulses were crossed in a plasma of density 4×10¹⁹ cm³. Energy was observed to be transferred from the higher-power to the lower-power pulse, increasing the amplitude of the plasma wave propagating in the direction of the latter. This results in increased electron self-trapping and plasma-wave acceleration gradient, which led to an increased number of hot electrons (by 300%) and hot-electron temperature (by 70%) and a …

Criss-Crossing Laser Beams Zoom Electrons Along, P. Zhang, N. Saleh, Shouyuan Chen, Z.M. Sheng, Donald P. Umstadter

Donald Umstadter Publications

Crossing two high-intensity laser beams in a plasma (a collection of charged particles) can have some interesting effects. In a recent experiment performed by researchers at the University of Michigan and the Institute of Physics in China, energy from a higher-power laser pulse was transferred to a lower-power laser pulse. The lower-power pulse had been accelerating electrons with its "wakefield" (like a wave accelerating a surfer). The extra energy to this lower-power pulse enhanced the electron acceleration and decreased the divergence of the electron beam. These features are desirable for proposed "laser particle accelerators" that would be powered by relatively …

Volume 41, Number 14: November 28, 2003, University Of North Dakota

University Letter Archive

No abstract provided.

Preparation And Characterization Of Y-Type Carbon Nanotubes By Using Anodized Alumina Oxide (Aao) Template, Jing Zhang, Quan-Yong Gao, Yong Yang

Journal of Electrochemistry

In this work, potential-modulation method was used in two-step anodization process to make an AAO template with Y-type nanochannels. Then Y-type carbon nanotubes with controlled length and branch angle were prepared in the template based on chemical vapor decomposion (CVD) method with Co particles as catalyst and C₂H₂ as carbon source. The Y-type nanotube branches exhibit the angle distribution ranging from 20° to 120°. The results demonstrated that the oxidation potential should be responsible for the angles and length of the branches. Short pulse and high oxidation potential will result in the short and dense nanotube branches.

Study On The Gas Generation In Different Charging Voltage During Formation Process In Polymer Lithium-Ion Battery, Li Huang, Ming-Gang Jin, Hui-Qun Cai, Ming-Sen Zheng, Quan-Feng Dong, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

The gases of polymer lithium-ion battery (PLI) generated under different voltages during the first charging process were examined by means of gas chromatography (GC), and the mechanism of the gas generation was discussed. The electrolyte used in batteries was 1 mol/L LiPF₆-EC～DMC～EMC=1∶1∶1(in volume). The results showed that when the charging voltage is less than 2.5 V,  the main component of generated gases are H₂ and CO₂, and when the charging voltage is 2.5 V, EC begins to decompose. Due to the decomposition of EC, the main generated gas is C₂H₄ when the …

Application Of Hydrogen-Storage Alloy Electrode In Electrochemical Reduction Of Glucose, Hui Chen, You-Gen Tang, Zheng Tang

Journal of Electrochemistry

Electrolysis of glucose was performed at constant potential using hydrogen-storage alloy as catalytic reduction electrode. It was found that the superficial treatment and activation of hydrogen-storage alloy powder had obvious effects on improving the current efficiency of sorbitol. Under the optimums, current efficiency of sorbitol by electrolyzing glucose was over 94%. The yield of sorbitol was over 80%, the lifespan of electrode was tested and analyzed, the ways of regeneration were discussed.

Pitting Characteristics Of Cu-50/60ni Alloys In Nacl Solution, Jie Li, Yan Niu, Shi-Zhe Song

Journal of Electrochemistry

The pitting behavior of nanocrystalline Cu-50/60Ni and cast Cu-50/60Ni alloys in different concentration of NaCl solutions has been investigated using various electrochemical methods. A logarithmic dependence of the passive breakdown potential (E_b), which is established using dynamic potential scan technic, on the chloride concentration was obtained for both alloys. The study on pitting propagation of both alloys was carried out using potential step chronocurrent method. As long as pits initiate on both alloys, the pits on nanocrystalline Cu-Ni alloys develop faster than those on cast alloys.

Preparation And Properties Of The Composite Microporous Pvdf-Hfp/Sio2 Based Polymer Electrolytes, Bao-Wen Zhang, Lu Qi, Hui Hen, Xiao-Hui Zhu, Li-Yan Liu, Yun-Xiang Ci

Journal of Electrochemistry

Microporous PVDF-HFP/SiO₂ film were prepared using a solvent/nonsolvent method-phase inversion method and the volatile plasticizers DMC, DEC or PC. The conductivity of the films increased pore volume measured by a nonsolvent uptake method. The conductivity of 1.86×10^-3 S⋅m^-1 were obtained using the liquid electrolyte LiPF₆(1 M) in EC/DMC (1:1).

Electronic Structures And Geometries Of Lial, Liang-Gen Wu, Rong-Qin Wu, Li-Juan Chen, Zi-Zhong Zhu, Yong Yang

Journal of Electrochemistry

LiAl is an important anode material for lithium batteries. Based on the plane-wave method and first-principles pseudopotentials, the electronic and geometric properties of LiAl have been studied. The cohesive energies versus volumes of unit cell, energy band structures, electronic density of states and charge density distributions of LiAl under some important structures are presented. The reason of B32-structure as the ground-state of LiAl crystal has also been elucidated, which is owing to Al-Al atoms in B32-structure form strong diamond-type covalent bonds. The present theoretical ground state structure of LiAl is consistent with the experimental and other theoretical results.

Study On Degradation Of Phenol By Electrochemical Oxidation, Yue-Li Liu, Hong-Hua Ge

Journal of Electrochemistry

Electrochemical oxidation of phenol was carried out by the Dimensionally Stable Anodes (DSA) electrode, which has been discarded as waste by alkali chloride factory. The result indicates that a good phenol removal can be obtained under certain phenol concentration by the DSA electrode. The key factor in effecting phenol removal of electrochemical oxidation is applied current density, the following factors are pH, electrolyte concentration and phenol concentration. After experiments, the optimal test conditions are 30 mA/cm², pH 10, electrolyte concentration 10 mg/L, phenol concentration 10 mg/L.67% CODcr removal and 90% absorbance removal are gained by electrochemical oxidation for …

Electrochemical And In-Situ Scanning Tunneling Microscopy Studies On The Sb Underpotential Deposition On Cu Single Crystal Electrodes, Ji-Hong Wu, Jia-Wei Yan, Jing Tang, Wen-Yun Hu, Bing-Wei Mao

Journal of Electrochemistry

We report electrochemical and in-situ STM studies on Sb UPD onto Cu(111) and Cu(100) electrode surfaces in HClO₄ and H₂SO₄ solutions. The results indicate that the electrode surface structure as well as anion can considerably influence Sb UPD. Sb UPD on Cu(100) forms open adlayer structures, which is accompanied by surface alloying due to the more open structure of the (100) surface, On Cu(111), a more compact Sb adlayer is formed instead. Anion adsorption influences the dynamics as well as the adlayer structure of Sb UPD. Owing to the strong adsorption of SO₄^2-, …

Study On Electrochemical Behavior Of Sus316l Stainless Steel After Surface Modification, Cheng-Hao Liang, Liang Guo, Wan Chen, Jing-Xiao Liu

Journal of Electrochemistry

The surface modification for SUS316L stainless steel was carried out by electroplating Rh, ion beam assisted deposition Ta₂O₅ and sol-gel-derived TiO₂. In Tyrode's stimulated body fluid, the surface modified samples had been investigated with electrochemical techniques. The results indicated that the electrochemical stability and dissolution were improved significantly after surface modification. Moreover, as to ion beam assisted deposition Ta₂O₅ and Sol-gel-derived TiO₂ film, the metal's d orbit electron holes filled up by the oxygen electrons made against the adsorption of hydrogen. Thus the cathode process, which is controlled by the hydrogen …

The Study Of Green Corrosion Inhibitors For Mild Steel 907 In Natural Seawater Environment, Ping Gong, Min Du, Qing-Zhang Wang, Zhen-Jun Mu

Journal of Electrochemistry

Nine green compounds, including calcium gluconate, zinc gluconate, zinc sulfate, garlic, ACUSOL 445N, OS-15, APG, OCTA and STPP were selected according to the methods of molecule design and function groups prune. The functions of combined corrosion inhibitors mixed by the compounds mentioned above for mild steel in seawater were studied in this work using the methods of polarization curve and weight-loss.The best weight ratio and distinct synergistic effect of calcium gluconate, zinc sulfate and OCTA were studied by Latin experiment. The afgereffects of the best weight ratio corrosoin inhibitor were studied by subsection experiment. In this way, a kind of …

Optimizing Catalyst Layer Composition Of Pemfc By Orthogonal Method, Ming-Hua Wang, Xin-Jian Zhu, Guang-Yi Cao, Sheng Sui, Qing-Chun Yu, Ming-Ruo Hu, Zheng-Yu Fan

Journal of Electrochemistry

The optimal composition of catalyst layer in a PEMFC electrode was studied through orthogonal method. It was showed that the performance of hydrophilic electrodes, in which there is no PTFE in the catalyst layer, were more favorable than that of hydrophobic electrodes. According to this condition, the power density of PEMFC attained 0.37 w·cm^-2 when the Nafion loading was 1.4 mg·cm^-2, and the Pt loading was 0.4 mg·cm^-2 in the catalyst layer, using H₂ as fuel and air as oxidant both at atmospheric pressure. Additionally, the results showed that increasing Pt loading in Pt/C catalyst …

The Study On Carbon Nanotube-Loaded Pt Catalysts For Proton Exchange Membrane Fuel Cells, Hong Zhu, Feng-Juan Ge, Xiao-Hong Kang, Yu-Guo Yang, Yun-Hua Xu

Journal of Electrochemistry

Carbon nanotube-supported-platinum (Pt/CNTs) and carbon-supported-platinum (Pt/C) catalysts were synthesized by in-situ chemical reduction. They were analyzed using TEM and XRD, then made into electrodes to be part of assemable PEMFC for the performence tests. The resulted show that Pt clusters in both catalysts are of small particle size (about 4nm), and Pt/CNTs exhibits a higher catalytic activity than Pt/C.