Electrochemical Evaluation for Rust Preventive Properties of Rust Preventive Oils Coated on Fe-Cu-C Sintered Steel

Since Fe-Cu-C sintered steels are easily rusted, they are coated with rust preventive oils. High viscosity of those rust preventive oils decrease workability, and low viscosity deteriorates rust preventive performance. Therefore, it is necessary to develop new rust preventive oils with contradictory properties of low viscosity and superior rust prevention. However, precise methodology to evaluate rust prevention ability has not been established. In this study, we developed new technique to quantitatively evaluate rust prevention ability by measuring the open circuit potential through thin corrosive solution on Fe-Cu-C sintered steels coated with a rust preventive oils. As a result, the ability for rust prevention can be measured quantitatively, and it decreases slowly over time, with repeating destruction and restoration. Furthermore, it was found that the deteriorating processes of rust prevention ability for rust prevention oils are composed of three characteristics steps respectively. That is, in the first step the great open circuit potential changes from 0V to-0.3V with repetition were observed where the excellent rust prevention ability was kept, in the second step it decreases slowly from-0.1V to-0.4V with oscillation of the small potential changes where the gradual decrease of rust prevention ability was recognized and in the third step it decreases monotonously in the lower potential than-0.4V where the rust was observed because of the remarkable deteriorating of the rust prevention ability.

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Study Of Rust Preventive Characteristics Of Rust Preventive Oil From Polarization Curve Measurement

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0229 ◽

2015 ◽

Vol 60 (2) ◽

pp. 915-917 ◽

Cited By ~ 2

Author(s):

D. Iwashima ◽

K. Ejiri ◽

N. Nagase ◽

M. Hatakeyama ◽

S. Sunada

Keyword(s):

Corrosion Rate ◽

Polarization Curve ◽

High Viscosity ◽

Powder Materials ◽

Corrosive Solution ◽

Low Viscosity ◽

Sintered Steels ◽

Zn Addition ◽

Measurement Results ◽

Better Than

Abstract Fe-Cu-C sintered steels are widely used as powder materials, because of its small volumetric shrinkage. However, Cu, which acts as cathode enhance formation of rust Fe2O3·xH2O during fabrication. To prevent formation of Fe2O3·xH2O rust preventive oils are widely used. High viscosity of those rust preventive oils decrease workability. While, low viscosity degrade rust preventive performance. Therefore, it is necessary to develop new rust preventive oils with contradictory properties of low viscosity and superior rust prevention. In this study, we developed technique to quantitatively evaluate rust prevention ability by measuring polarization curve through thin corrosive solution on Fe-Cu-C sintered steels coated with rust preventive oils. The electrochemical measurements were carried out in corrosive solution of 0.35 mass % NaCl. Using a double capillary was added dropwise to the specimen. From the experimental, it is possible to evaluate the corrosion rate quantitatively in the surface of specimen, which was coated with rust preventive oil through thin corrosive solution. From the measurement results, Corrosion rate is reduced by coating the rust preventive oil. Especially, corrosion rate of the specimen coated with oil that showed best performance indicated 10000 times better than that of without oil ones. Zn addition negative correlation between corrosion rate and period of potential oscillation.

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Corrosion Behavior of Sealed Films on Anodized Al Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.233-235.1498 ◽

2011 ◽

Vol 233-235 ◽

pp. 1498-1501

Author(s):

Qi Zhou ◽

Chun Lin He ◽

Qing Kui Cai

Keyword(s):

Potentiodynamic Polarization ◽

Open Circuit Potential ◽

Corrosion Behaviour ◽

Sol Gel ◽

Open Circuit ◽

Green Technology ◽

Al Alloy ◽

Corrosion Mechanism ◽

Pitting Potential ◽

Corrosive Solution

Alumina sol sealing is one of new green technology for anodized Al alloy. The corrosion mechanism of films sealed by sol and corrosion behaviour of films sealed by sol, Na2Cr2O7, boiling water were analyzed by their curves of open circuit voltage-time (E-T) and potentiodynamic polarization curve. It is found that corrosion tendency of sol sealing film is less than other sealed films by E-T inspection. Fluctuation of open-circuit potential is furious in the immersing prophase and slows down in the anaphase for anodized sealed films. At this time corrosive reactions gradually reach steady state. Open-circuit potential greatly waves for the rough sealed films. Potentiodynamic polarization curves of sealed films show that passive area is the longest for films sealed by sol which has the minimum corrosive current , the passivate current, anodic current and cathode current, but the maximum pitting potential and open-circuit potential. Corrosion parameters are the second for the film sealed by dichromate. Anodic reactions are strongly inhibited by sol sealing films in Cl- corrosive solution. Sol sealing films weaken cathode O2 depolarize reaction. Cl- ions erode anodized Al material on which covered with sol film and produce corrosion. The corrosion of sol-gel film goes through two periods: pitting induced phase and pitting corrosion period.

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Users behaviors: The Heritage of Digital World

INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY ◽

10.24297/ijct.v13i7.2512 ◽

2014 ◽

Vol 13 (7) ◽

pp. 4675-4682

Author(s):

Atefeh Danesh Moghadam ◽

Alireza Alagha

Keyword(s):

Technology Development ◽

Second Step ◽

Information Communication ◽

The Third ◽

Digital World ◽

New Concepts ◽

Emerging Patterns ◽

History Of ◽

Fourth Step ◽

Communication And Technology

In the advent of information era, not only digital world is going to expand its territories, it is going to penetrate into the traditional notions about the meaning of the words and also valorize new concepts. According to Oxford Dictionary, the word heritage is defined: The history, tradition and qualities that a country or society has had for many years and that are considered an important part of its character. In order to present how emerging patterns, as the consequences of technology development, are going to be considered as the new concept of heritage, we follow four steps. In the first step, we present the convergence of Information, Communication and Technology (ICT) and a concise history of its convergence. In the second step, we argue how convergence has culminated in emerging patterns and also has made changes in digital world. In the third step, the importance of users behaviors and its mining is surveyed. Finally, in the fourth step; we illustrate User Generated Contents (UGC) as the most prominent users behaviors in digital world.

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The Kinney Three Paragraphs (and More) for Accounting Ph.D. Students

Accounting Horizons ◽

10.2308/acch-52451 ◽

2019 ◽

Vol 33 (4) ◽

pp. 1-14 ◽

Cited By ~ 9

Author(s):

William R. Kinney

Keyword(s):

Review Process ◽

Student Experiences ◽

Second Step ◽

Practical Relevance ◽

The Third ◽

Validity Assessment ◽

Essential Components ◽

Potential Problems ◽

Empirical Accounting Research

SYNOPSIS This Commentary is intended to help beginning Ph.D. students identify, evaluate, and communicate essential components of proposed empirical accounting research using a three-step process. The first step is a structured top-down approach of writing answers to three related questions—What, Why, How—that emphasize the central role of conceptual thinking in research design, as well as practical relevance. The second step is a predictive validity assessment that anticipates concerns likely to arise in the scholarly review process, and the third is consideration of the likely outcome and potential problems to be encountered if the proposal is implemented as planned. First-hand accounts of Ph.D. student experiences using the three paragraphs and three-step approach are presented, along with an exercise that beginners can use to help themselves identify, analyze, and anticipate problems to improve chances for research success ex ante.

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Adsorption and Oxidation of Thiosulfate on the Platinum Electrode in a Slightly Alkaline Medium

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20000001 ◽

2000 ◽

Vol 65 (1) ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Tomáš Loučka

Keyword(s):

Alkaline Medium ◽

Oxidation Reaction ◽

Open Circuit Potential ◽

Platinum Electrode ◽

Adsorbed Layer ◽

Open Circuit ◽

Adsorbed Hydrogen ◽

Oxidation Number ◽

Hydrogen Electrode ◽

Layer Region

The aim of this research was to study the oxidation and reduction of the adsorbed thiosulfate on the platinum electrode in a slightly alkaline medium. The adsorption was performed at the open circuit conditions. The reduction of the adsorbed layer in the hydrogen region is slower in a slightly alkaline medium than in acid. The mechanism of reduction and oxidation of adsorbed molecules is probably the same. The nonstationary currents measured in presence of thiosulfates showed that the change in the oxidation number does not take place during the adsorption in the double layer region. In the hydrogen region, thiosulfate replaces the adsorbed hydrogen while beeing reduced. Nonstationary currents at higher concentrations of thiosulfate indicate the presence of more layers on the electrode. Upon reaching higher concentrations of thiosulfate the oxidation reaction takes place between thiosulfate in solution and adsorbed product of its reduction. The open circuit potential of the platinum electrode measured in a thiosulfate solution was 0.780 and 0.783 V against the hydrogen electrode in the same solution.

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Effects of Alloying Elements on the Corrosion Behavior of Sputter–deposited Zr–(12–21)Cr–W Alloys in 0.5 M NaCl Solution

Journal of Nepal Chemical Society ◽

10.3126/jncs.v25i0.3305 ◽

1970 ◽

Vol 25 ◽

pp. 75-82

Author(s):

Basu Ram Aryal ◽

Jagadeesh Bhattarai

Keyword(s):

Corrosion Test ◽

Open Circuit Potential ◽

Chemical Society ◽

Open Circuit ◽

Sputter Deposition ◽

Nacl Solution ◽

Corrosion Rates ◽

Sputter Deposited ◽

Stable Passivity ◽

Zirconium Metal

The synergistic effect of the simultaneous additions of tungsten and zirconium in thesputter-deposited amorphous or nanocrystalline Zr-(12-21)Cr-W alloys is studied in 0.5 MNaCl solution open to air at 25°C using corrosion tests and open circuit potentialmeasurements. Corrosion rates of the sputter-deposited Zr-(12-21)Cr-W alloys containing10-80 at % tungsten (that is, 0.95-1.85 x 10-2 mm.y-1) are more than one order of magnitudelower than that of the sputter-deposited tungsten and even lower than those of zirconium aswell as chromium in 0.5 M NaCl solution. The addition of 8-73 at % zirconium content inthe sputter-deposited binary W-(12-21)Cr alloys seems to be more effective to improve thecorrosion-resistant properties of the sputter-deposited ternary Zr-Cr-W alloys containing12-21 at % chromium in 0.5 M NaCl solution. The sputter-deposited Zr-(17-21)Cr-W alloyscontaining an adequate amounts of zirconium metal showed the more stable passivity andshowed higher corrosion resistance than those of alloy-constituting elements in 0.5 M NaClsolution open to air at 25°C.Keywords: Zr-(12-21)Cr-W alloys, sputter deposition, corrosion test, open circuit potential,0.5 M NaCl.DOI: 10.3126/jncs.v25i0.3305Journal of Nepal Chemical Society Volume 25, 2010 pp 75-82

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A Low-Viscosity BisGMA Derivative for Resin Composites: Synthesis, Characterization, and Evaluation of Its Rheological Properties

Materials ◽

10.3390/ma14020338 ◽

2021 ◽

Vol 14 (2) ◽

pp. 338

Author(s):

Ali Alrahlah ◽

Abdel-Basit Al-Odayni ◽

Haifa Fahad Al-Mutairi ◽

Bashaer Mousa Almousa ◽

Faisal S. Alsubaie ◽

...

Keyword(s):

Substantial Reduction ◽

Triethylene Glycol ◽

High Viscosity ◽

Resin Matrix ◽

Resonance Spectroscopy ◽

Dental Resin ◽

Triethylene Glycol Dimethacrylate ◽

Oh Groups ◽

Low Viscosity ◽

13C Nuclear Magnetic Resonance

This study aimed to synthesize new bisphenol A-glycidyl methacrylate (BisGMA) derivatives, targeting a reduction in its viscosity by substituting one of its OH groups, the leading cause of its high viscosity, with a chlorine atom. Hence, this monochloro-BisGMA (mCl-BisGMA) monomer was synthesized by Appel reaction procedure, and its structure was confirmed using Fourier transform infrared spectroscopy, 1H and 13C-nuclear magnetic resonance spectroscopy, and mass spectroscopy. The viscosity of mCl-BisGMA (8.3 Pa·s) was measured under rheometry conditions, and it was found to be more than 65-fold lower than that of BisGMA (566.1 Pa·s) at 25 °C. For the assessment of the viscosity changes of model resins in the presence of mCl-BisGMA, a series of resin matrices, in which, besides BisGMA, 50 wt % was triethylene glycol dimethacrylate, were prepared and evaluated at 20, 25, and 35 °C. Thus, BisGMA was incrementally replaced by 25% mCl-BisGMA to obtain TBC0, TBC25, TBC50, TBC75, and TBC100 blends. The viscosity decreased with temperature, and the mCl-BisGMA content in the resin mixture increased. The substantial reduction in the viscosity value of mCl-BisGMA compared with that of BisGMA may imply its potential use as a dental resin matrix, either alone or in combination with traditional monomers. However, the various properties of mCl-BisGMA-containing matrices should be evaluated.

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A Conceptional Approach of Resin-Transfer-Molding to Rosin-Sourced Epoxy Matrix Green Composites

Aerospace ◽

10.3390/aerospace8010005 ◽

2020 ◽

Vol 8 (1) ◽

pp. 5

Author(s):

Sicong Yu ◽

Xufeng Zhang ◽

Xiaoling Liu ◽

Chris Rudd ◽

Xiaosu Yi

Keyword(s):

Composite Laminates ◽

Resin Transfer Molding ◽

High Viscosity ◽

Ramie Fiber ◽

Liquid Composite Molding ◽

Curing Agent ◽

Molding Process ◽

Transfer Molding ◽

Low Viscosity ◽

Composite Molding

In this concept-proof study, a preform-based RTM (Resin Transfer Molding) process is presented that is characterized by first pre-loading the solid curing agent onto the preform, and then injecting the liquid nonreactive resin with an intrinsically low viscosity into the mold to infiltrate and wet the pre-loaded preform. The separation of resin and hardener helped to process inherently high viscosity resins in a convenient way. Rosin-sourced, anhydrite-cured epoxies that would normally be regarded as unsuited to liquid composite molding, were thus processed. Rheological tests revealed that by separating the anhydrite curing agent from a formulated RTM resin system, the remaining epoxy liquid had its flowtime extended. C-scan and glass transition temperature tests showed that the preform pre-loaded with anhydrite was fully infiltrated and wetted by the liquid epoxy, and the two components were diffused and dissolved with each other, and finally, well reacted and cured. Composite laminates made via this approach exhibited roughly comparable quality and mechanical properties with prepreg controls via autoclave or compression molding, respectively. These findings were verified for both carbon and ramie fiber composites.

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Miniaturization effect of electroosmotic self-propulsive microswimmer powered by biofuel cell

ROBOMECH Journal ◽

10.1186/s40648-019-0146-x ◽

2019 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Toshiro Yamanaka ◽

Fumihito Arai

Keyword(s):

Theoretical Model ◽

Femtosecond Laser ◽

Polymer Composites ◽

Open Circuit Potential ◽

Vascular System ◽

Conductive Polymer ◽

Open Circuit ◽

Biofuel Cell ◽

Remarkable Feature ◽

Conductive Polymer Composites

AbstractFor future medical microrobotics, we have proposed the concept of the electroosmotic self-propulsive microswimmer powered by biofuel cell. According to the derived theoretical model, its self-propulsion velocity is inversely proportional to the length of the microswimmer, while it is proportional to the open circuit potential generated by the biofuel cell which does not depend on its size. Therefore, under conditions where those mechanisms work, it can be expected that the smaller its microswimmer size, the faster its self-propulsion velocity. Because of its remarkable feature, this concept is considered to be suitable as propulsion mechanisms for future medical microrobots to move inside the human body through the vascular system, including capillaries. We have already proved the mechanisms by observing the several 10 μm/s velocity of 100 μm prototypes fabricated by the optical photolithography using several photomasks and alignment steps. However, the standard photolithography was not suitable for further miniaturization of prototypes due to its insufficient resolution. In this research, we adopted femtosecond-laser 3D microlithography for multi-materials composing of the conductive polymer composites and nonconductive polymer composite and succeeded in fabricating 10 μm prototypes. Then we demonstrated more than 100 μm/s velocity of the prototype experimentally and proved its validity of the smaller and faster feature.

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