Physical Sciences and Mathematics Commons^™

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Phase Two, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Development Of Dose Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton

Transmutation Sciences Physics (TRP)

A research consortium comprised of representatives from several universities and national laboratories has been established as part of this on-going project to generate internal and external dose conversion coefficients for radionuclides produced in spallation neutron sources. Information obtained from this multi-year study will be used to support the siting and licensing of future accelerator-driven nuclear initiatives within the U.S. Department of Energy complex, including the Spallation Neutron Source (SNS) and Accelerator Production of Tritium (APT) Projects. Determination of these coefficients will also fill data gaps for several hundred radionuclides that exist in Federal Guide Report No. 11 and in Publications …

Design And Evaluation Of Processes For Fuel Fabrication, Georg F. Mauer

Fuels Campaign (TRP)

The objective of this project is the design and evaluation of manufacturing processes for transmuter fuel fabrication. The large-scale deployment of remote fabrication and refabrication processes will be required for all transmutation scenarios. Current program emphasis is on a five-year effort to determine the feasibility of transmutation as a technology to limit the need for repository storage of spent commercial fuel. The evaluation of the fabrication processes will create a decision support data base to document design, operations, and costs. Fabrication processes required for different fuel types differ in terms of equipment types, throughput, and cost. Differential cost Implications of …

Building Trusted Paths For Web Browsers, Zishuang (Eileen) Ye

Dartmouth College Master’s Theses

The communication between the Web browser and the human user is one component of the server-client channel. It is not the user but the browser that receives all server information and establishes the secure connection. The browser's user interface signals, such as SSL lock, https protocol header et al., indicate whether the browser-server communication at the current moment is secure. Those user interface signals indicating the security status of browser should be clearly and correctly understood by the user.

A survey of modern Web browsers shows the information provided by current browsers is insufficient for users to make trust judgment. …

The Compilation And Analysis Of Data Relevant To A U.S. Claim Under United Nations Law Of The Sea Article 76: A Preliminary Report, Larry A. Mayer, Martin Jakobsson, Andy Armstrong

Center for Coastal and Ocean Mapping

No abstract provided.

Sustainable Agriculture : Pragmatism, Distinctions On Artifacts And The Role Of The Land Ethic, Dustin Mulvaney

Theses

This thesis will explore the ethical dimensions of global agriculture from the productionist paradigm to the land ethic in the context of the sustainable agriculture promoted in the fair trade, shade grown, and organic coffee movements. Much of the sustainable development debate in the environmental ethics literature has centered on justifications (from anthropocentric and nonanthropocentric worldviews) for preserving nature. Since agriculture is an artifact of human sedentary civilization, traditional nonanthropocentric arguments do not suffice because of the tendency to focus exclusively on natural systems. Building on the work of Katz's "Pragmatic ReConsideration" and Light's "methodological pragmatism," the role of anthropocentric …

Novel Synthesis Of 2-Methyl-3, 4, 5-Trichloropyrimidine, Daniel M. Goldman

Theses

A one-step synthesis of the heterocycle 2-methyl-3,4,5-trichloropyrimidine by the cycloaddition of hexachloropropene with acetamidine hydrochloride in methanolic NaOH was attempted. The product was dark amber oil. A by-product of this reaction was sodium chloride. The proposed reaction was expected to proceed via a SN2 nucleophilic displacement of three chlorine atoms on hexachloropropene by acetamidine, the nucleophile. The proposed driving force for this transformation is the lone pair of electrons on the amidine nitrogen along with the electron withdrawing ability of three chlorines on hexachloropropene which induces a partial positive charge on the carbon. It is proposed that the chlorine atoms …

An Evolving Approach To Learning In Problem Solving And Program Development : The Distributed Learning Model, Idania Espinosa

Theses

Technological advances are paving the way for improvements in many sectors of society. The US education system needs to undergo a transformation of existing pedagogical methods to maximize utilization of new technologies. Traditional education has primarily been teacher driven, lectured-based in one location. Advances in technology are challenging existing paradigms by developing tools and educational environments that reach diverse learning styles and surpass the boundaries of current teaching methods.

Distributed learning is an emerging paradigm today that has promise to contribute significantly to learning and improve overall academic success. This research first explores various systems that provide different modes of …

Agricultural Land Reform Policy In Western Ukraine : The Influence Of Environmental History And Ethics, Andrew B. Wowk

Theses

Agricultural land privatization is an important environmental and economic policy within Ukraine, which is transitioning to a market-based economy. This thesis studied the influence of bioregional environmental history and environmental ethics on land privatization in Western Ukraine, within Lviv oblast, through historical research and field research of private farmers.

Historical research showed that due to its environmental history, the study area was particularly receptive to land privatization after Ukraine's independence in 1991. Field research indicated that farmers in the study area generally see private ownership of land as better for humans and the environment than collective land ownership. The farmers …

Slippage And Change Point Problem With Directional Data., Arnab Kumar Laha Dr.

Doctoral Theses

In this thesis we develop statistical methods for dealing with two problems namely (1) THE SLIPPAGE PROBLEM and (2) THE CHANGE POINT PROB- LEM in the set-up of directional data. In this chapter, we provide an intro- duction to these problems and discuss the importance of the present work. The slippage problem is basically a problem to detect whether any unspecified observation in a given random sample comes from a distribution different from that for all the other remaining observations. This can also be viewed as a problem of outlier detection or that of spuriosity. This problem assumes great importance …

The Electrochemical Etching Of Metals, Li-Min Jiang, Zhong-Qun Tian, Zhu-Fang Liu, Bin-Wei Mao, Hai-Gou Huang, Jian-Jun Sun

Journal of Electrochemistry

All kinds of current methods for etching metals are reviewed.The electrochemical etching methods among them,including through_mask,scanning electrochemical microscopy,confined etchant layer technique,electrochemical scanning tunneling microscopy and super_short potential pulse,are discussed in detail.The compositive analyses were made for the methods in terms of the processing precision(whether processing in micrometer or nanometer scale),the processing efficiency(the complexity of the procedure,and whether fabricating in batch),the extent of application(mainly refer to the procedure,and whether fabricating in batch),the extent of results was shown that each method has itself advantage and imperfection. The confined etchant layer technique has superiority over other methods in the view of the total …

An Investigation On Sr-Doped Spinel Phase-Lisr Xmn _(2-X ) O _4, Hui Zhan, Yun-Hong Zhou

Journal of Electrochemistry

Sr_doped spinel phase_LiSrxMn 2-x O4 was successfully prepared by solid_state method. Structural and electrochemical characterizations were carried out. Although Sr 2+ has a large ion radius_1.12 ,the spinel structure can be well maintained for LiSrxMn 2-x O4 sample as far as the x value doesn't surpass 0.05. Electrochemical study presents supporting evidence that doping the stoichiometric LiSrxMn 2-x O4 phase with Sr is an effective way to improve the cycleability of LiSrxMn 2-x O4 spinel material. A remarkable enhancement of the cycleability with retention of the initial capacity >90 % after 95 cycles was observed for the Sr_doped spinel.

Corrosive Electrochemical Behavior Of Carbon Steel In Microbiological Medium, Jing Liu, Hong-Bo Fan, Hai-Ping Xu, Jia-Shen Zheng, Li-Ming Xu, Zong-Qiang Mao

Journal of Electrochemistry

Sulfate_reducing bacteria(SRB)grows and propagates, PH of the solution is dropped from 7.5 to 5.8,and forms the biofilms on carbon steel in culture medium.The micro_environment on the surface of carbon steel is changed under the biofilms,the factors accelerate the formation of the pitting corrosion. When the biofilm on carbon steel is cleaned out,the surface of carbon steel have the non_uniform pitting corrosion. The activity of SRB and the porous structure of biofilms induced the initiation and development of the pitting corrosion of carbon steel.The process of microbiologically induced corrosion(MIC) involves the development of SRB activity,which promotes the permeation of gydrogen into …

Effect Of Precondition On Porous Silicon Formation, Xuan Cheng, Guang-Feng Luo

Journal of Electrochemistry

In this work, effect of precondition on porous silicon formation was investigated by performing electrochemical polarization measurements. The surface morphologies and optical properties of the samples were also studied by scanning electron microscopy (SEM) and Raman spectrometer. It was demonstrated that precondition enhanced the chemical/electrochemical reactions occurred at Si/solution interface and the growth of porous silicon, which ultimately resulted in a red shift in photoluminescence. However, the thickness of porous silicon decreased with the increase of precondition time. More broad bands were observed with prolonged precondition.

The Preparation And Characterization Of Growing Preferentially Cds Nanopartile Film, Huai-Guo Huang, Yan-Yan Xi, Zhi-Xin Zheng, Jia-Wei Yan, Jian-Zhang Zhou, Ling-Ling Wu, Zhong-Hua Lin

Journal of Electrochemistry

CdS nanoparticle films were prepared on the PANI film,PATP film,Au film and ITO respectively by constant current deposition or current impulse method,and their structure and character were also studied.The results show that the substrates influence the structure and character of CdS particle film.

Syntheses And Photoluminescence Of Zinc Oxide Polyaniline Coaxial Nanowires And Their Array, Zhi-Xin Zheng, Yan-Yan Xi, Ping Dong, Huai-Guo Huang, Jian-Zhang Zhou, Lin-Lin Wu, Zhong-Hua Lin

Journal of Electrochemistry

A novel nanomaterial,zinc oxide (ZnO) and polyaniline (PANI) coaxial nanowires and their array in the template,was synthesized using anodic aluminum oxide (AAO) membrane as template.The morphology of these coaxial nanowires was observed with transmission electron microscope (TEM).The experiments on photoluminescence (PL) of coaxial nanowires and their array in AAO membrane show that the visible emission band of ZnO shifts from 530 nm to 400 nm and the luminescence is enhanced for the coaxial nanowires array in AAO membrane,and the visible emission band shifts to a lower wavelergth(385 nm) for coatial nanowires in NaOH solution. Possible explanations for these two blue …

Satellite Imagery Proves Essential For Monitoring Erupting Aleutian Volcano, Kenneson Dean, Jonathan Dehn, Stephen R. Mcnutt, Christina Neal, Richard Moore, Dave Schneider

School of Geosciences Faculty and Staff Publications

Mt. Cleveland is one of more than 40 active volcanoes in Alaska that is monitored by the Alaska Volcano Observatory (AVO). It is located on the western half of Chuginadak, a remote and uninhabited island in the east central Aleutians that lies 1526 km southwest of Anchorage. The closest inhabited community, Nikolski, is 75 km to the east on Umnak Island (Figure 1). Mt. Cleveland erupted explosively on 19 February and on 11 and 19 March 2001. Because the volcano is not yet monitored with seismic, deformation, or other geophysical instruments, satellite imagery was the only effective tool for detecting …

Development Of 200～500 W Portable Proton Exchange Membrane Fuel Cell Power System, Li-Qing Hu, Li-Rong Zhou, Zheng Li, Jian-Wei Xia, Ming-Zhu Fu, Xin Wu, Yun Zhu

Journal of Electrochemistry

The Properties of the Portable PEM Fuel Cell Power Source are very unique compared with the common primary or rechargeable electro_chemical battery. This paper describes the In this work, of the 200～500 W portable PEM fuel cell power system, was developed. The system mainly composed of four subsystem:1)Fuel cell stack;2)Air delivery;3)Hydrogen source;4)Heat dissipation and system control.

Electrocatalytic Oxidation Of Formaldehyde On The Proline Film Modified Electrode, Yu-Rong Ma, Qiu-Xia Yang, Guo-Bao Li, Zheng-Kai Xi, Xue-Lin Wang

Journal of Electrochemistry

The proline film modified electrode and its electrochemical behavior was studied by cyclic voltammetry and spectroelectrochemistry . After incorporation of Ni(Ⅱ), the cyclic voltammograms of the proline Ni(Ⅱ) film electrode exhibited a typical redox peak, which appeared at potential of 0.52 V anodic and 0.44 V cathodic in NaOH. The formal potentials E ' were linearly dependent on the pH, and the peak currents ip were linearly dependent on the square root of the scan rates,thus charge transfer in the film was controlled by diffusion. The diffusion coefficient is figured out to be 2×10 -10 cm 2·s -1 . The …

Recent Developments In The Electrolyte For Lic _6/Electrolyte/Cathode Battery, Cui-Ying Wang, Sheng-Liang Zhao, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

We present a reviewed the development and status of electrolyte for LiC 6/electrolyte/cathode battery. The effect of the salt, solvent, additive and impurity on the conductivity of the electrolyte, formation of the solid_electrolyte_interphase (SEI) and cycle life of the battery were described.

Application Of Electrochemical Techniques To The Researches In Life Science, Jian-Tao Pang, Chun-Hai Fan, Gen-Xi Li

Journal of Electrochemistry

The research work of our group in the last two years is briefly reviewed in this paper. By using electrochemical method, and combining some other chemical and biological techniques, lots of achievements have been obtained. And these researches are towards some hot topics in life science, such as function conversion, interaction between signal molecules and proteins, electron_transfer of biomolecules, gene detection, structural biology, biochemical analysis and the third generation biosensors.

Electrochemical Properties Of Mixed Metal Oxide Coated Titanium Anodes In Seawater, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen

Journal of Electrochemistry

Mixed metal oxide coated titanium anodes prepared by thermal decomposition were characterized by scanning electron microscopy and electrochemical measurement, while the consumption rate of an anode was also measured in seawater. In order to examine the practical performances of mixed metal oxide_coated anodes, a simulating test on floating dock in seawater has also been carried out. The SEM results indicate that oxide layers exhibited a cracked_mud morphology which endows the anode with good electrocatalytic activity. The electrochemical measurements showed that mixed metal oxide_coated anodes exhibit excellent electrochemical activity and electrochemical stability in seawater. Owing to good corrosion resistance and low …

A Blend Conducting Membranes For Direct Methanol Fuel Cells, Lei Li, Jun Zhang, Hong Wu, Yu-Xin Wang

Journal of Electrochemistry

An attempt was made to modify membranes for direct methanol fuel cells by blending Nafion or polystyrene sulfonic acid (PSSA) with polyvinylidene fluoride (PVDF) from their solutions. The proton conductivity and methanol barrier property as a function of the membrane compositions are discussed. Compared with the Nafion  117 membrane, the PVDF_Nafion blend membranes with 25 wt% of Nafion showed a decrease in the conductivity by about 2 orders of magnitude, and the methanol barrier properties increased about 3 orders of magnitude. If the ratio (σ/P) is adopted to characterize the performance of the membrane, the PVDF_PSSA and PVDF_Nafiion blend …

Preparation,Structure And Properties Of Electrochromic Rhodium Oxide Films, Hai-Hong Wang, Tao Wang, Man-Ming Yan, Zhi-Yu Jiang

Journal of Electrochemistry

Electrochromic rhodium oxide films were prepared on ITO substrate by sol_gel method. The films exhibited reversible two_color (bright yellow at reduction and dark green at oxidation) electrochromic behavior in alkaline solution with good cycle stability. In_situ XRD, TGA_DTA, IR, XPS methods were used for studying the structure and chemical process of the films. The diffusion coefficient during the electrochromic process was measured by electrochemical impedance spectra method. It was found that the rhodium oxide films may be suitable for the use in electrochromic devices.

Studies On Sulfate Reducing Bacteria Influenced Corrosion Of 90/10 Cu/Ni Alloy, Guang-Zhou Liu, Jian-Hua Qian, Yan Ma, Jian-Hua Wu

Journal of Electrochemistry

Electrochemical techniques such as measurements of corrosion potential,the polarization resistance,and potentiodynamic scanning technique were used to investigate the electrochemical behavior of 90/10 Cu/Ni alloy in Postgate C medium containing sulfate reducing bacteria(SRB).The results showed that the corrosion potential of the alloy changed from -0.20 to -0.75 V(SCE) when bacteria inocula was added, and the polarization resistance R p decreased obviously,which corresponds to an increased corrosion rate. The shape ofthe anodic polarization curves was drastically changed in the presence of SRB, and an active_passive transition was observed. Electron probe microanalyzer was used to investigate the morphology and chemical composition of the …

Polishing Rate And Dependent Factors Of Copper In Nh_3·H _2o Aqueous Solution Containing K _3fe(Cn)_6 During Cmp, Han-Wei He, Yue-Hua Hu, Ke-Long Huang

Journal of Electrochemistry

Dependence of polishing rates of copper on concentrations of NH 3·H 2O, passivator K 3,γ_Al 2O 3 abrasives and polishing pressures, polishing rotative rates were studied. Dependent mechanisms were explained. It was shown a linear relation between polishing and polishing pressures and rotative rates within some range, non_linear relation between polishing and various reagent concentrations. Preston coefficient was varied. CMP recipe of the best polishing rate was gained: 4%K 3Fe(CN) 6+1%NH 3·H 2O+25%γ-Al 2O 3, K p=0.023 83. Technics conditions were 300 rpm and 80 kpa. The best polishing effect was R a=50 nm, R max =400 nm.

Electrosynthesis Of Glyoxylic Acid In A Cooled Cathode Reactor, Jin-Hong Fan, Jun Li, Xue-Yun Chen, Wei Li, Hao-Qi Gao

Journal of Electrochemistry

Glyoxylic acid was produced by electroreduction of oxalic acid in a well designed cooled cathode reactor. The cathodic and anodic electrolytes were super_saturated oxalic acid and hydrochloric acid aqueous solutions separated by a super_acid ion_exchange membrane. The current efficiency and time_space yield of glyoxylic acid were studied under different temperatures of cathode and electrolyte,current densities,materials of cathode. With the cooled cathode reactor, the energy consumption was reduced and higher oxalic acid concentration was available in solution, so that current efficiency was improved. The results indicated that the average time_space yield of glyoxylic acid was about 0.032 kg·dm -3 ·h -1 …

Self-Assembled Monolayer Of Schiff Bases On Au Electrode, Ke-Qiang Ding, Qing-Fei Wang, Zhen-Bin Jia, Na Tian, Ning Wang, Ru-Ting Tong, Xin-Kui Wang, Hui-Bo Shao

Journal of Electrochemistry

Schiff bases tailored with _SH group,was self_assembled on Au substrate for the first time.The packing degree of this monolayer was described with SEM technique.Spontaneously,the self_assembled monolayer (SAM) was briefly characterized with CV and EIS methods.Though Comparing with the SAM of alkanethiol,the membrane we fabricated was relatively loose,our work is the first step to study Schiff bases by means of self_assembled monolayer.

Determination Of Novalgin With Second Order Differential Simple Oscillographic Voltammetry, Fu-Fang Tao, Hong-Fang Zhang, Xun-Yu Xiong, Jian-Bin Zheng

Journal of Electrochemistry

Based on the oscillographic characteristic of novalgin that incision can be caused at -1.2 V( vs .SCE) in 0.1 mol·L -1 KNO 3 , a new electronanlytical method, second order differential simple oscillographic voltammetry for the determination of novalgin was found. The method was applied to the determination of novalgin in tablet. The calibration graph is linear from 5.0×10 -6 to 5.0×10 -5 mol·L -1 with a detection limit of 2×10 -6 mol·L -1 . The relative standard deviation of the method is 2.1% for 3.00×10 -5 mol·L -1 novalgin.The determination results showed that the simple oscillographic voltammetry is a …

Effect Of Cl - On The Transition Current Density Of Zn During The Electrodeposition Of Zn-Ni Alloys, Ren-He Yin, Zheng-Hua Fang, Wei-Min Cao

Journal of Electrochemistry

There exists a transition current density of Zn when the normal co_deposition of Zn_Ni alloys at chloride baths turns to anomalous type.The value increases with Cl - concentration, but is independent of pH, this is because the existence of Cl - decreases the evolution overpotential of Ni metal and has a catalytic effect on it.