The Mechanism of Formation of Iron Oxide and Oxyhydroxides in Aqueous Solutions at Room Temperature(Chemistry)

For a better understanding of the atmospheric rusting of iron and steels, the present work is aimed to explore the mechanism of formation of green rusts, Fe_3O_4, α-FeOOH, β-FeOOH, γ-FeOOH, δ-FeOOH and amorphous ferric oxyhydroxide in aqueous solution at room temperature. The formation processes on which end products are determined are strongly affected by the oxidation rate, pH and the structure and composition of initial and intermediate species of iron. The systematic diagram of formation processes of iron oxide and oxyhydroxides has been presented, in which both dissolved and solid species of iron are included

Passivity of Extremely Corrosion Resistive Iron Alloys

This paper reviews studies on corrosion resistance of chromium bearing amorphous iron alloys and high purity-high chromium ferritic steels containing molybdenum. High corrosion resistance of these alloys have been interpreted in terms of the compositions and functions of the passive films formed on these alloys

XPS Determination of Compositions of Alloy Surfaces and Surface Oxides on Mechanically Polished Iron-Chromium Alloys(Metallurgy)

Using the XPS technique, the compositions of the alloy surface and the surface oxide on mechanically polished iron-chromium alloys were studied. For quantitative analysis, the ratio of photo-ionization cross section of Fe 2p_ electrons to that of Cr 2p_ electrons was estimated as 1.35 for Al Kα_ radiation. Assuming a homogeneous oxide layer, the thickness of the oxide layer and compositions of the alloy surface and the surface oxide were simultaneously determined. The results showed no enrichment of chromium or iron either in the oxide layer or the alloy surface. Results on binding energies were also given

New synthetic method and ionic conductivity of Na-4-mica

ArticleMATERIALS LETTERS. 60(4): 464-466 (2006)journal articl

ESCA Study of the Passive Film on an Extremely Corrosion-Resistant Amorphous Iron Alloy

X-ray photoelectron spectroscopy was applied to study the composition of the passive film formed on an extremely corrosion resistant amorphous Fe-10at.%Cr-13at.%P-7at.%C alloy in 1 N HCl. The passive film consists mainly of hydrated chromium oxyhydroxide which is a common major constituent of passive films on crystalline stainless steels. The extremely high corrosion resistance of the amorphous alloy can only in part be attributed to the formation of a protective hydrated chromium oxyhydroxide film

Formation of Fe(II)_1-Fe(III)_3 Green Complex on Oxidation of Ferrous Ion in Perchloric Acid Solution

The interaction between Fe(II)-Fe(III) in strong acidic solution has been investigated by means of electronic and Raman spectra, magnetic susceptibility measurement and chemical analysis of the solution. It was found that the green intermediate complex having an absorption band at 337 nm was formed on oxidation of Fe(H_2O)^_6 in perchloric acid solution. The Fe(II)/Fe(III) ratio in the green complex was a third. The configuration of the complex consisting of Fe(II)-O-Fe(III) oxo-bridges was suggested

Spectroscopical Approach to the Mechanism of the Rebinder Effects in MgO Immersed in N, N-dimethylformamide or Dimethylsulfoxide

The mechanism of the Rebinder effects is proposed from a point of view of the formation of barrier against the dislocation movement caused by strong chemisorption. The infrared and electronic spectra of N, N-dimethylformamide or dimethylsulfoxide adsorbed on MgO indicate that the adsorption may be accompanied by a charge transfer from these compounds to MgO. The proposed mechanism can explain the difference of the near-surface dislocation mobility in MgO immersed in N, N-dimethylformamide or dimethylsulfoxide

A Multi-Armed Bandit to Smartly Select a Training Set from Big Medical Data

With the availability of big medical image data, the selection of an adequate training set is becoming more important to address the heterogeneity of different datasets. Simply including all the data does not only incur high processing costs but can even harm the prediction. We formulate the smart and efficient selection of a training dataset from big medical image data as a multi-armed bandit problem, solved by Thompson sampling. Our method assumes that image features are not available at the time of the selection of the samples, and therefore relies only on meta information associated with the images. Our strategy simultaneously exploits data sources with high chances of yielding useful samples and explores new data regions. For our evaluation, we focus on the application of estimating the age from a brain MRI. Our results on 7,250 subjects from 10 datasets show that our approach leads to higher accuracy while only requiring a fraction of the training data.Comment: MICCAI 2017 Proceeding

Enhanced Next Generation Millimeter-Wave Multicarrier System with Generalized Frequency Division Multiplexing

Orthogonal Frequency Division Multiplexing (OFDM) is a popular multicarrier technique used to attain high spectral efficiencies. It also has other advantages such as multipath tolerance and ease of implementation. However, OFDM based systems suffer from high Peak-to-Average Power Ratio (PAPR) problem. Because of the nonlinearity of the power amplifiers, the high PAPR causes significant distortion in the transmitted signal for millimeter-wave (mmWave) systems. To alleviate the high PAPR problem, this paper utilizes Generalized Frequency Division Multiplexing (GFDM) which can achieve high spectral efficiency as well as low PAPR. In this paper, we show the performance of GFDM using the IEEE 802.11ad multicarrier frame structures. IEEE 802.11ad is considered one of the most successful industry standards utilizing unlicensed mmWave frequency band. In addition, this paper indicates the feasibility of using GFDM for the future standards such as IEEE 802.11ay. This paper studies the performance improvements in terms of PAPR reduction for GFDM. Based on the performance results, the optimal numbers of subcarriers and subsymbols are calculated for PAPR reduction while minimizing the Bit Error Rate (BER) performance degradation. Moreover, transmitter side ICI (Intercarrier Interference) reduction is introduced to reduce the receiver load