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Study Of Localized Corrosion Of Metals By Using The Electrochemical Techniques With Spatial Resolution, Chang-Jian Lin, Xiang-Dong Zhuo, Zu-De Feng, Rong-Gui Du, Zhao-Wu 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 …

Electrochemical Surface Characterization Of Titanium Alloy(Ti-6al-4v), Jian-Zhong Chen, Qing-Liang Gao, Zhong-Yi Wang, Wen-Jing Xue

Journal of Electrochemistry

With its low density and high strength ratio, titanium alloy(Ti₆Al₄V) 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 …

Some Effects Of Co On The Electrochromic Properties Of NioXHY Film, Xiao-Yan Cao, Wen-Hu Zhang, Hua-Tang Yuan, Wan-Lin Zhang, Yin-Nong Lin, Zuoxiang Zhou, Yunshi Zhang

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/Zro2 Composite Electrodeposition, Qun-Jia Peng, Dao-Bin Mu, Ju-Sheng Ma, Xiang-Yun Tang

Journal of Electrochemistry

The effects of cathodic current density and amount of particle dispersion in solution on the codeposition of Ni/ZrO₂ 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 …

Kinetic Study Of Electrooxidation Of Benzene, Xin-Sheng Zhang, Ping Ding, Ying-Chun Dai, Wei-Kang Yuan

Journal of Electrochemistry

A reaction kinetic study for electrochemical oxidation of benzene was performed on a PbO₂ rotating disk electrode in 1 mol/L H₂SO₄ 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, Yung-Fa Lee, Ting-Yu Wang, Wen-Ta 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, Wei-Wei Lin, Sheng-Xian Wang, Jian-Qing Zhang, Jun Yuan, Zhen-Guo Ji

Journal of Electrochemistry

A new polymer E-T was 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 NaNO₂, especially in low NaNO₂ concentration. The EIS showed that E-T …

Study On Steel Corrosion In Simulated Biofilm Environment In Seawater, Qing-Fei Wang, Jing Sui, Run-Xi Su, De-Ying Kong, Shi-Zhe 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 E2, 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.

Structural And Electrochemical Studies On Todorokite/Vernadite As Cathodes For Rechargeable Lithium Ion Batteries, Wei Chu, De-Yao Liu, Jin-Kua You, Yong Yang, Zu-Geng 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 …

Study Of Electrochemistry Of Tetrasulphonated Phthalocyanine Zinc In Aqueous And Nonaqueous Solvents, Er-Sheng Liu, Yi-Qun Wu, Jian-Hui Yang, Li-Ying Huang, Jun-Dong Wang, Su-Ling Yang, Nai-Sheng Chen, Jin-Ling 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.

Studies Of Electrochemical Characteristics Of Pasted Nickel Hydroxide Electrode With Surface Deposited Cobalt, Xian-You Wang, Yun-Shi Zhang, Jie Yan, Zheng Zhu, Hua-Tang Yuan, De-Ying 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, Ying-Xin Zhao, Chang-Yan 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, Hong-Feng Xu, Bao-Lian 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 …

Electrodeposition Of Neodymium-Iron Group Alloy Films In (P-Ch3C6H4So3)3Nd System, Peng Liu, Ye-Xiang Tong, Qi-Qin Yang, Yan-Sheng 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-CH₃C₆H₄SO₃) 3Nd + MCl₂(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 …

Oxidation Mechanism Of Hypophosphite, Dong-Bai Sun, Ying Jin, Hong-Ying Yu, De-Jun 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 H₂PO₂^- to H₂PO₃^-, 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 H₂PO₂^-, i.e. peak Ⅱ corresponds to the oxidation process of …

Effect Of Stress On Electrochemical Behaviour Of Various Thermal History Zones And Different Phase Structures On The Weldment For Low Alloy Steel, Yin-Shun Wu, De-Yu Liu, Bei Cao, Feng-Li Wang, Zhi Fang, Lin Zhang, Zheng-Rong 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 …

Electrohydrodimerization Of Fumarodinitrile On Liquid Gallium Electrode, He Wei, Huang Ying, Sheng-Tao Zhang

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.

The New Hampshire, Vol. 88 [89], No. 35 (Feb. 26, 1999), The New Hampshire

The New Hampshire Print Edition

An independent student produced newspaper from the University of New Hampshire. This volume was printed as 88, but it is the 89th volume in the series. This was corrected in pencil.

Board Of Trustees Minutes, February 26, 1999, Eastern Washington University

Board of Trustees Minutes

No abstract provided.

Whalesong 1999-02-26 (V.20 No.9), N/A N/A

Whalesong

No abstract provided.

Volume 36, Number 25: February 26, 1999, University Of North Dakota

University Letter Archive

No abstract provided.

Otter Realm, February 26, 1999, Vol. 4 No. 9, California State University, Monterey Bay

The Otter Realm

Lighting Needed on Campus -- Students Want Healthy Choices -- CSUMB Students Included in Tellus Survey -- Alumni Association Growing and Active -- Carpet Removed in MLC -- CSUMB Student Raising Funds for AIDS Ride -- OLLIN Club -- DegenerAsian X! Are You Ready? -- Whose Black History Do We Believe? -- Opening Girls' Eyes to the Possibilities in Science -- An Evening with Dee Dee Bridgewater at CSUMB -- Message of Community at the Heart of Musical Offering: Linda Tillery and the Cultural Heritage Choir Open Black History Month Celebration -- CSUMB's World Theater offers a high performance Venue

Marketing Alfalfa Hay: What The Consumer Demands, Tom Keene

Kentucky Alfalfa and Stored Forage Conference

Anytime we address selling a product to the consumer; our first objective should always be to sell a quality product. However before we get into quality, I think we need to back up and understand that quality can vary from customer to customer depending upon the type of livestock he is feeding. For instance, if you are selling hay to a dairy operation, how is the hay being utilized? Is it being fed free choice? Is it going into a milking TMR (total mixed ration)? Is it going to feed young stock, breeding heifers, or sick animals? Each group of …

How I Produce And Market Alfalfa Hay, John Nowak

Kentucky Alfalfa and Stored Forage Conference

John Nowak was born March 22, 1947, in New York City and was raised in Westchester County, just north of New York City. After graduating from Colorado State University with a B.S. degree in farm and ranch management, he entered the U.S. Army. John served on active duty from 1969 until 1978. In 1975, his Army career brought him to Fort Campbell, Kentucky, and he began farming part-time in Christian County in 1976. As with many "start-from-scratch" farmers, John's first farming efforts involved producing burley tobacco during the years 1976 through 1979. In 1979, he began a cow-calf and backgrounding …

Grazing Alfalfa, Garry D. Lacefield, Jimmy C. Henning

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is a high yielding, high quality, deep-rooted, versatile forage legume well adapted throughout the U.S. Gains per animal and per acre can be excellent with acceptable stand persistence when present technology is used. Is grazing alfalfa right for everyone? No. Is grazing alfalfa right for you? Only you can answer that question. This presentation attempts to give you information that will hopefully help you with that answer.

What I Have Learned From 4 Years Of Alfalfa Grazing Tolerance Variety Trials, Jimmy C. Henning, Robert Spitaleri, Garry D. Lacefield, Charles T. Dougherty

Kentucky Alfalfa and Stored Forage Conference

There has been interest in alfalfa varieties that would tolerate grazing for some time. The spreading type alfalfas (such as Rambler, Spredor 2, Travois) have long been generally promoted as being tolerant of grazing. Over the years, most selection for tolerance to grazing was done using frequent clipping to simulate grazing.

Studies conducted at the University of Georgia in the 1980's found that alfalfa varieties performed differently when grazed frequently compared to clipping frequently. This line of research eventually led to the release of 'AlfaGraze' alfalfa which was the first variety ever to be selected primarily by overgrazing by livestock. …

Practical And Economical Ways To Increase Alfalfa Hay Drying Rates, Michael Collins

Kentucky Alfalfa and Stored Forage Conference

Hay stores well for long periods and is better suited to cash sale and transportation than silage and remains the most popular method for harvesting the alfalfa crop. Rapid drying reduces field losses by reducing respiration and by reducing the incidence of rain damage during curing. Because of these factors, harvest losses are greatest for very dry forage and are low for very wet material like direct cut silage. However, the latter is subject to excessive storage losses due to seepage and to quality deterioration. Storage losses are generally minimized by harvesting at low moisture levels.

Alfalfa Following Alfalfa: What Works And What Doesn't Work?, Monroe Rasnake

Kentucky Alfalfa and Stored Forage Conference

Farmers often would like to go directly back into alfalfa when an old stand plays out. However, research has shown that it is often difficult to get new stands established when this is done. Some of the problems may be attributed to weeds, insects and diseases that build up over time and become difficult to control. Another reason is that alfalfa plants have been shown to produce chemical compounds that can inhibit germination and growth of new seedlings. This effect is called allelopathy or autotoxicity.

Secrets To Getting A Good Stand Of Alfalfa, Jimmy C. Henning, Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

Getting a good stand of alfalfa quickly is very important to Kentucky because it is the highest yielding, highest quality forage crop. In addition, it can be used in many different ways. Cool wet springs and hot dry falls have caused alfalfa seedings to fail in recent years. It would be easy to begin to believe that there was some 'magic' step or ingredient that has been missing. There are no magic steps to getting a good stand. Attention to a few major details can help maximize your chances of success.

What Grasses Work Best With Alfalfa?, Timothy D. Phillips

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is the "queen" of forages, but many situations exist where it is desirable or necessary to grow alfalfa in a mixture with a forage grass rather in monoculture. Some of the reasons to grow grass with alfalfa are: improved yield (in terms of tons of dry matter produced), better seasonal yield distribution, better weed control, potential pest reduction, erosion prevention, bloat risk reduction, and accelerated hay-drying rates. Conversely, there are some factors that favor alfalfa monoculture. These include: lower forage quality, especially in terms of protein content; more difficult management requirements (herbicide use, fertilization, and harvest timing); and, lower …