Physical Sciences and Mathematics Commons^™

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 …

Ams Radiocarbon Chronology Of Glacier Fluctuations In The South Shetland Islands During The Last Glacial/Interglacial Hemicycle:Implications For Global Climate Change, Brenda L. Hall

University of Maine Office of Research Administration: Grant Reports

This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for …

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

Effects Of Deposit-Feeder Gut Passage And Fecal Pellet Encapsulation On Germination Of Dinoflagellate Resting Cysts, David Shull, Anke Kremp, Donald M. (Donald Mark) Anderson

Environmental Sciences Faculty and Staff Publications

Many species of dinoflagellates spend much of their lives buried in sediments as resting cysts. While on the bottom, cysts may pass through the guts of deposit feeders before conditions become favorable for germination. Little is known, however, about how dinoflagellate cysts are affected by deposit-feeder digestion, fecal pellet formation, and translocation within the sediment column. To answer the question of whether gut passage or pelletization reduces cyst germination, we fed cysts of the dinoflagellate Scrippsiella lachrymosa to 3 polychaete deposit feeders, Capitella sp., Streblospio benedicti, and Polydora cornuta. Fecal pellets of these species have different morphologies …

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 …

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 LiPF6_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 H2 and CO2, and when the charging voltage is 2.5 V, EC begins to decompose. Due to the decomposition of EC, the main generated gas is C2H4 when the charge voltages between 3.0 V and 3.5 V. As …

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 HClO4 and H2SO4 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 SO42-, the UPD of Sb on Cu(111) in …

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.

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 Ta2O5 and sol_gel_derived TiO2. 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 Ta2O5 and Sol_gel_derived TiO2 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 reduction,was held back. X_ray diffraction analysis of SUS316L stainless steel …

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 high effect green corrosion inhibitor was obtained.

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.

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.

Adsorption And Oxidation Of Phenol Electrode Processes, Bao-Cheng Wang, Yan-Ping Sun, Jin-Hua Zhu

Journal of Electrochemistry

The electrochemical behaviors of platinum electrode were studied by cyclic voltammetry in 1mol/L sulfuric acid solution and 1mol/L sulfuric acid solution contained phenol. The adsorption characteristics of phenol and the intermediat on electrode surface have been discussed. The reactive reversibility and oxidation mechanism of phenol on electrode process have been investigated.The potential of characteristic adsorption was suggested. The various products woud be formed when the electrode potential was greater than the one of characteristic adsorption.

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 C2H2 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.

Preparation And Properties Of The Composite Microporous Pvdf-Hfp/Sio_2 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/SiO2 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 Sm-1 were obtained using the liquid electrolyte LiPF6(1 M) in EC/DMC (1:1).

The Current Fluctuations Of Carbon Steel In Nano_2-Nacl Solutions, Yu-Ming Tang, Yu Zuo

Journal of Electrochemistry

The characteristics of current fluctuations of A3 carbon steel in NaNO2_NaCl solutions were studied with potentiostatic and potentiodynamic polarization methods. The steel remained stable passivation in 0.1 mol/L NaNO2 solution without Cl-. After NaCl was added in to the solution, current fluctuations with a characteristic of quick increase and slow decrease occurred, indicating quick dissolution and slow re_passivation of the metastable pits. The metastable pitting may cause accumulated corrosion damage around certain area and result in observable pits. With the increase of chloride concentration, the occurring potential for metastable pits Em rised, and peak values and frequency of current fluctuations …

Determination Of Cystine By Second Order Differential Simple Oscillographic Voltammetry, Fu-Fang Tao, Jian-Bin Zheng

Journal of Electrochemistry

In 0.2 mol/L NaOH, cystine can cause an sensitive incision at -0.5 V (vs.SCE) of cathodic branch of dE/dt_E curve or second order differential simple oscillogram. Based on the oscillographic charateristic, second order differential simple oscillographic voltammetry was applied to the determination of cystine in tablet. The linear range and the detection limit for determination of cystine were 2.5×10-6～3.5×10-5 mol/L and 1.0×10-6 mol/L, respectively. The relative standard deviation for 2.000×10-5 mol/L cystine was 1.8% (n=5).

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 H2 as fuel and air as oxidant both at atmospheric pressure. Additionally, the results showed that increasing Pt loading in Pt/C catalyst was a reasonable way to …

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.

Effect Of Dspp Al_2o_3 On Electrical Properties Of Polymer Electrolyte, Hai-Fen Xie, Xiao-Xiang Sun, Yi-Pin Wang, Guang-Yuan Li

Journal of Electrochemistry

The PEO_NaSCN polymer solid electrolytes by adding dispersed second phase particles (DSPP) of Al2O3 were studied. The characteristics of solid electrolytes and conductivity values are dependent on DSPP Al2O3 sizes and its contents. It was found that when the Al2O3 sizes are less than 1 μm, which is a criticle size, the sample conductivities were larger than those of the pure PEO_NaSCN samples and when the Al2O3 sizes are larger than 1 μm then the sample conductivities are less then those of the pure samples. The maximum conductivity appears when the content of Al2O3 is 25% .Low frequency and high …

Study On Degradation Of Phenol By Electrochemical Oxidation, Yueli 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/cm2, 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 2 hours.

An Alternative Mechanism For The Dimerization Of Formic Acid, Nicole R. Brinkmann, Gregory S. Tschumper, Ge Yan, Henry F. Schaefer

Chemistry Faculty Research & Creative Works

Gas-phase formic acid exists primarily as a cyclic dimer. The mechanism of dimerization has been traditionally considered to be a synchronous process; however, recent experimental findings suggest a possible alternative mechanism by which two formic acid monomers proceed through an acyclic dimer to the cyclic dimer in a stepwise process. To investigate this newly proposed process of dimerization in formic acid, density functional theory and second-order Møller - Plesset perturbation theory (MP2) have been used to optimize cis and trans monomers of formic acid, the acyclic and cyclic dimers, and the acyclic and cyclic transition states between minima. Single-point energies …

Unified Cross-Validation Methodology For Selection Among Estimators And A General Cross-Validated Adaptive Epsilon-Net Estimator: Finite Sample Oracle Inequalities And Examples, Mark J. Van Der Laan, Sandrine Dudoit

U.C. Berkeley Division of Biostatistics Working Paper Series

In Part I of this article we propose a general cross-validation criterian for selecting among a collection of estimators of a particular parameter of interest based on n i.i.d. observations. It is assumed that the parameter of interest minimizes the expectation (w.r.t. to the distribution of the observed data structure) of a particular loss function of a candidate parameter value and the observed data structure, possibly indexed by a nuisance parameter. The proposed cross-validation criterian is defined as the empirical mean over the validation sample of the loss function at the parameter estimate based on the training sample, averaged over …

Efficient Grazing Systems: Putting Pieces Together, Charles T. Dougherty

Kentucky Grazing Conference

Pros and cons of grazing systems are well-known to this audience. Efficient grazing systems, however, are a different story. What is an efficient grazing system? I think we could argue that topic until the cows come home and I do not believe we could come to any agreement. I am going to approach the subject of efficiency from several angles but you will probably see them differently. Economic efficiencies will not be covered.

Kentucky Goat Friendly Pasture Concepts, Terry Hutchens

Kentucky Grazing Conference

Goats are accomplished grazers of grass and browse plants. In addition, they can be managed within a grazing system both intensively or extensively as long as quality forage is made available. Goats are facultative browsers, they prefer to feed at eye level and upward and then feed on forage from the top of the plant down. Goats prefer to move freely from plant to plant-removing foliage from select portions of plants. Foliage meals are dictated by quality factors that insure adequate protein and energy levels. Each stem or leaf is clipped with precision leaving the forage residue standing equal in …

Effective Use Of Pastures For Horses, Robert Coleman

Kentucky Grazing Conference

Pastures can serve two very necessary functions for the care and maintenance of horses. Not only do these areas of grasses and legumes provide a place for the horse to exercise, they can provide a significant portion of the horse’s nutrient requirement. Horses evolved as a grazing animal, so it is reasonable that many classes of horse can be adequately maintained on well-managed pastures.

The Economics Of Integrating Crop Land To Mig Grazing, Edward N. Ballard

Kentucky Grazing Conference

Illinois soils vary in their properties and producing capacities. Large areas of the state have soils that are among the most productive in the world. Other areas have soils that, because they are too steep or droughty or have some other undesirable features, are not the most productive for corn and soybeans.

However, over the past 30 years there has been a trend to place more acres in Illinois in corn and soybeans and less acres in small grains, legumes and pasture crops. Government incentive programs have encouraged more acres to be place into corn and soybean production.

Environmental Benefits With Improved Grazing, David Stipes

Kentucky Grazing Conference

The public is becoming better educated about the environment and will continually question activities that are perceived as being harmful to soil, water, air, plants, people, animals and other concerns. Livestock producers who implement well-planned grazing management systems have an excellent opportunity to compliment both production and natural resource conservation considerations. All segments of the population involved in production agriculture will be held accountable for environmental impacts that result from their operation. A proactive approach is needed by livestock and other agricultural producers to sustain the protection of the environment that is in harmony with a healthy ecosystem. All those …

Grazing Systems For Beef Cattle, John Johns

Kentucky Grazing Conference

Beef cattle represent the most important grazing livestock enterprise to Kentucky producers. As of January 1, 2003 there were 1,120,000 producing beef brood cows on 39,000 farms in the state. In addition, more than 600,000 yearling cattle are also produced. The number of total beef animals is increasing as producers put more economic reliance on beef and forage programs. In many cases, beef cattle represent the only practical method of converting high quality forage to income for producers.