Investigation of electrochemical synthesis of ferrate, Part I: Electrochemical behavior of iron and its several alloys in concentrated alkaline solutions

In recent years, considerable attention has been paid to various applications of Fe(VI) due to its unique properties such as oxidizing power, selective reactivity, stability of the salt, and non-toxic decomposition by-products of ferric ion. In environmental remediation processes, Fe(VI) has been proposed as green oxidant, coagulant, disinfectant, and antifoulant. Therefore, it is considered as a promising multi-purpose water treatment chemical. Fe(VI) has also potential applications in electrochemical energy source, as 'green cathode'. The effectiveness of ferrate as a powerful oxidant in the entire pH range, and its use in environmental applications for the removal of wide range of contaminants has been well documented by several researchers. There is scientific evidence that ferrate can effectively remove arsenic, algae, viruses, pharmaceutical waste, and other toxic heavy metals. Although Fe(VI) was first discovered in early eighteen century, detailed studies on physical and chemical properties of Fe(VI) had to wait until efficient synthetic and analytical methods of Fe(VI) were developed by Schreyer et al. in the 1950s. Actually, there have been developed three ways for the preparation of Fe(VI) compounds : the wet oxidation of Fe(II) and Fe(III) compounds, the dry oxidation of the same, and the electrochemistry method, mainly based on the trans passive oxidation of iron. High purity ferrates Fe(VI) can be generated when electrode of the pure iron metal or its alloys are anodized in concentrated alkaline solution. It is known that the efficiency of electrochemical process of Fe(VI) production depends on many factors such as current density, composition of anode material, types of electrolyte etc. In this paper, the electrochemical synthesis of ferrate(VI) solution by the anodic dissolution of iron and its alloys in concentrated water solution of NaOH and KOH is investigated. The process of transpassive dissolution of iron to ferrate(VI) was studied by cyclic voltammetry, galvanostatic and potentiostatic pulse method. Cyclic voltammetry gave useful data on potential regions where ferrate(VI) formation is to be expected in the course of transpassive anodic oxidation of iron and some of its alloys, and its stability in the electrolytes of different composition. In addition, step-wise oxidation of iron in anodic oxidation is confirmed. Galvanostatic pulse experiments confirmed the character of successive anodic oxidation of iron, as the three-step process of ferrate(VI) formation is clearly observed. In the cathodic pulse complex reduction of ferrate (VI), firstly to Fe(III) species and then to mixed Fe(II) and Fe(III) compounds and finally to elementary iron is confirmed. The significant difference between the mechanisms of anodic oxidation of pure iron and low carbon steel at the one side and electrical ferrous-silicon steel at the other is observed. The influence of material chemical composition on the electrochemical behavior of electrode in course of anodic polarization in strong alkaline solutions is discussed in terms of composition of passivating layer formed on the electrode. On the base of the experimental data, efficient synthesis of ferrate(VI) can be expected in the region of anodic potentials between + 0,55 and + 0,75 V against Hg|HgO reference electrode in the same solution, depending on the anode materials composition, in the alkaline electrolytes concentration between 10 and 15 M.

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Cyclic Voltammetry Studies on Electrochemical Behavior of the Composite Ni-P+TiO2 Electrocatalysts in Alkaline Solutions

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.228.207 ◽

2015 ◽

Vol 228 ◽

pp. 207-212

Author(s):

B. Łosiewicz ◽

Magdalena Popczyk ◽

A. Budniok

Keyword(s):

Cyclic Voltammetry ◽

Electrochemical Behavior ◽

Alkaline Solutions ◽

Electrochemical Characteristics ◽

Composite Component ◽

Anode Polarization ◽

Temperature Conditions ◽

Naoh Solution

Electrochemical characteristics of the composite Ni-P+TiO2electrocoatings with a differentiated content of TiO2composite component from 14 to 20 at.%, dependent on temperature conditions of electrodeposition from 293 to 333 K, was carried out in an alkaline 2.5 M NaOH solution. Cyclic voltammetry studies of the Ni-P+TiO2coatings and comparable Ni-P electrocatalysts revealed that cyclic cathode-anode polarization activated TiO2as the embedded composite component for the Ni-P+TiO2coating obtained at 333 K only.

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Electrochemical synthesis of some 1,2-dimethyl 1,2-disubstituted ethylenes

Canadian Journal of Chemistry ◽

10.1139/v79-163 ◽

1979 ◽

Vol 57 (9) ◽

pp. 990-993 ◽

Cited By ~ 8

Author(s):

Roger N. Renaud ◽

Philippe J. Champagne

Keyword(s):

Physical Properties ◽

Anodic Oxidation ◽

Electrochemical Synthesis ◽

Sodium Acetate ◽

Water Solution ◽

Low Concentration

The anodic oxidation of sodium acetate in the presence of a series of 1,2-disubstituted ethylenes was performed in acetonitrile–water solution. Under low concentration of substrates, very good yields of the monomeric 1,2-dimethylated products were obtained. In the case of diethyl fumarate, an increase in concentration caused a decrease in the ratio of monomer to polymer when all other parameters were held constant.The stereoisomers of the products were separated and their physical properties are reported.

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Influence of electrode material on the electrochemical behavior of the absorbing solution of the quinhydrone method of gases purification from hydrogen sulfide

Chemistry, Technology and Application of Substances ◽

10.23939/ctas2021.01.053 ◽

2021 ◽

Vol 4 (1) ◽

pp. 53-59

Author(s):

А. V. Slyuzar ◽

◽

І. P. Mertsalo ◽

M. І. Kozub ◽

P. V. Myliutyna ◽

...

Keyword(s):

Cyclic Voltammetry ◽

Hydrogen Sulfide ◽

Anodic Oxidation ◽

Exposure Time ◽

Electrode Material ◽

Electrochemical Behavior ◽

Electrode Materials ◽

Catalytic Properties ◽

Oxidation Reactions ◽

Carbonate Solutions

The electrochemical behavior of carbonate solutions of the quinhydrone at different concentrations 1, 5, 10, 20, and 30 g/dm3 at the exposure time 0…12 days on different electrode materials – Ni and Au were studied by the cyclic voltammetry (CV) method. The catalytic properties of gold different from nickel in the anodic oxidation reactions of the quinhydrone catalyst are noted.

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Biochemical and molecular characterization of Alternaria alternata isolates highly resistant to procymidone from broccoli and cabbage

Phytopathology Research ◽

10.1186/s42483-021-00092-z ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Bingran Wang ◽

Tiancheng Lou ◽

Lingling Wei ◽

Wenchan Chen ◽

Longbing Huang ◽

...

Keyword(s):

Alternaria Alternata ◽

Single Point ◽

Sodium Dodecyl ◽

Cross Resistance ◽

Molecular Characteristics ◽

Single Point Mutation ◽

Wide Range ◽

Significant Difference ◽

Leaf Blights ◽

High Level

AbstractAlternaria alternata, a causal agent of leaf blights and spots on a wide range of hosts, has a high risk of developing resistance to fungicides. Procymidone, a dicarboximide fungicide (DCF), has been widely used in controlling Alternaria leaf blights in China for decades. However, the resistance of A. alternata against DCFs has rarely been reported from crucifer plants. A total of 198 A. alternata isolates were collected from commercial fields of broccoli and cabbage during 2018–2019, and their sensitivities to procymidone were determined. Biochemical and molecular characteristics were subsequently compared between the high-level procymidone-resistant (ProHR) and procymidone-sensitive (ProS) isolates, and also between ProHR isolates from broccoli and cabbage. Compared with ProS isolates, the mycelial growth rate, sporulation capacity and virulence of most ProHR isolates were reduced; ProHR isolates displayed an increased sensitivity to osmotic stresses and a reduced sensitivity to sodium dodecyl sulfate (SDS); all ProHR isolates showed a reduced sensitivity to hydrogen peroxide (H2O2) except for the isolate B102. Correlation analysis revealed a positive cross-resistance between procymidone and iprodione, or fludioxonil. When treated with 10 μg/mL of procymidone, both mycelial intracellular glycerol accumulations (MIGAs) and relative expression of AaHK1 in ProS isolates were higher than those in ProHR isolates. Sequence alignment of AaHK1 from ten ProHR isolates demonstrated that five of them possessed a single-point mutation (P94A, V612L, E708K or Q924STOP), and four isolates had an insertion or a deletion in their coding regions. No significant difference in biochemical characteristics was observed among ProHR isolates from two different hosts, though mutations in AaHK1 of the cabbage-originated ProHR isolates were distinct from those of the broccoli-originated ProHR isolates.

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Antifungal Activity of Propyl Disulfide from Neem (Azadirachta indica) in Vapor and Agar Diffusion Assays against Anthracnose Pathogens (Colletotrichum gloeosporioides and Colletotrichum acutatum) in Mango Fruit

Microorganisms ◽

10.3390/microorganisms9040839 ◽

2021 ◽

Vol 9 (4) ◽

pp. 839

Author(s):

Muhammad Rafiullah Khan ◽

Vanee Chonhenchob ◽

Chongxing Huang ◽

Panitee Suwanamornlert

Keyword(s):

Antifungal Activity ◽

Mycelial Growth ◽

Colletotrichum Gloeosporioides ◽

Colletotrichum Acutatum ◽

Model Parameters ◽

Pathogenicity Test ◽

Agar Diffusion ◽

Wide Range ◽

Significant Difference ◽

Diffusion Assay

Microorganisms causing anthracnose diseases have a medium to a high level of resistance to the existing fungicides. This study aimed to investigate neem plant extract (propyl disulfide, PD) as an alternative to the current fungicides against mango’s anthracnose. Microorganisms were isolated from decayed mango and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum. Next, a pathogenicity test was conducted and after fulfilling Koch’s postulates, fungi were reisolated from these symptomatic fruits and we thus obtained pure cultures. Then, different concentrations of PD were used against these fungi in vapor and agar diffusion assays. Ethanol and distilled water were served as control treatments. PD significantly (p ≤ 0.05) inhibited more of the mycelial growth of these fungi than both controls. The antifungal activity of PD increased with increasing concentrations. The vapor diffusion assay was more effective in inhibiting the mycelial growth of these fungi than the agar diffusion assay. A good fit (R2, 0.950) of the experimental data in the Gompertz growth model and a significant difference in the model parameters, i.e., lag phase (λ), stationary phase (A) and mycelial growth rate, further showed the antifungal efficacy of PD. Therefore, PD could be the best antimicrobial compound against a wide range of microorganisms.

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A Threat of Farmers’ Suicide and the Opportunity in Organic Farming for Sustainable Agricultural Development in India

Sustainability ◽

10.3390/su11082400 ◽

2019 ◽

Vol 11 (8) ◽

pp. 2400 ◽

Cited By ~ 4

Author(s):

Karthikeyan Mariappan ◽

Deyi Zhou

Keyword(s):

Organic Farming ◽

Tamil Nadu ◽

Agricultural Development ◽

Small Scale ◽

Conventional Farming ◽

Wide Range ◽

Significant Difference ◽

Small Scale Farmers ◽

The Cost ◽

Input Cost

Agriculture is the main sources of income for humans. Likewise, agriculture is the backbone of the Indian economy. In India, Tamil Nadu regional state has a wide range of possibilities to produce all varieties of organic products due to its diverse agro-climatic condition. This research aimed to identify the economics and efficiency of organic farming, and the possibilities to reduce farmers’ suicides in the Tamil Nadu region through the organic agriculture concept. The emphasis was on farmers, producers, researchers, and marketers entering the sustainable economy through organic farming by reducing input cost and high profit in cultivation. A survey was conducted to gather data. One way analysis of variance (ANOVA) has been used to test the hypothesis regards the cost and profit of rice production. The results showed that there was a significant difference in profitability between organic and conventional farming methods. It is very transparent that organic farming is the leading concept of sustainable agricultural development with better organic manures that can improve soil fertility, better yield, less input cost and better return than conventional farming. The study suggests that by reducing the cost of cultivation and get a marginal return through organic farming method to poor and small scale farmers will reduce socio-economic problems such as farmers’ suicides in the future of Indian agriculture.

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4K 3-dimensional video microscope system (orbeye) for transsphenoidal pituitary surgery

Acta Neurochirurgica ◽

10.1007/s00701-021-04762-x ◽

2021 ◽

Author(s):

Roman Rotermund ◽

Jan Regelsberger ◽

Katharina Osterhage ◽

Jens Aberle ◽

Jörg Flitsch

Keyword(s):

3D Visualization ◽

Remission Rate ◽

Subjective Evaluation ◽

Pituitary Surgery ◽

Image Resolution ◽

Wide Range ◽

Significant Difference ◽

Duration Of Surgery ◽

Video Microscope ◽

Transsphenoidal Pituitary Surgery

Abstract Background In previous reports on experiences with an exoscope, this new technology was not found to be applicable for transsphenoidal pituitary surgery. As a specialized center for pituitary surgery, we were using a 4K 3D video microscope (Orbeye, Olympus) to evaluate the system for its use in transsphenoidal pituitary surgery in comparison to conventional microscopy. Method We report on 296 cases performed with the Orbeye at a single institution. An observational study was conducted with standardized subjective evaluation by the surgeons after each procedure. An objective measurement was added to compare the exoscopic and microscopic methods, involving surgery time and the initial postoperative remission rate in matched cohorts. Results The patients presented with a wide range of pathologies. No serious events or minor complications occurred based on the usage of the 4K 3D exoscope. There was no need for switching back to the microscope in any of the cases. Compared to our microsurgically operated collective, there was no significant difference regarding duration of surgery, complications, or extent of resection. The surgeons rated the Orbeye beneficial in regard to instrument size, positioning, surgeon’s ergonomics, learning curve, image resolution, and high magnification. Conclusions The Orbeye exoscope presents with optical and digital zoom options as well as a 4K image resolution and 3D visualization resulting in better depth perception and flexibility in comparison to the microscope. Split screen mode offers the complementary benefit of the endoscope which may increase the possibilities of lateral view but has to be evaluated in comparison to endoscopic transsphenoidal procedures in the next step.

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Surface Tension and Density of Liquid Hot Work Tool Steel W360 by voestalpine BÖHLER Edelstahl GmbH & Co KG Measured with an Electromagnetic Levitation Apparatus

International Journal of Thermophysics ◽

10.1007/s10765-020-02765-x ◽

2020 ◽

Vol 42 (2) ◽

Author(s):

Thomas Leitner ◽

Anna Werkovits ◽

Siegfried Kleber ◽

Gernot Pottlacher

Keyword(s):

Surface Tension ◽

Temperature Dependence ◽

Linear Model ◽

Tool Steel ◽

Pure Iron ◽

Electromagnetic Levitation ◽

Liquid Density ◽

Hot Work Tool Steel ◽

Significant Difference ◽

Main Component

AbstractW360 is a hot work tool steel produced by voestalpine BÖHLER Edelstahl GmbH & Co KG, a special steel producer located in Styria, Austria. Surface tension and density of liquid W360 were studied as a function of temperature in a non-contact, containerless fashion using the oscillating drop method inside an electromagnetic levitation setup. For both, surface tension and density, a linear model was adapted to present the temperature dependence of these measures, including values for the uncertainties of the fit parameters found. The data obtained are compared to pure iron (with 91 wt% the main component of W360), showing an overlap for the liquid density while there is a significant difference in surface tension (− 5.8 % at the melting temperature of pure iron of 1811 K).

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The plastic deformation of iron and the formation of Neumann lines

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1925.0070 ◽

1925 ◽

Vol 108 (745) ◽

pp. 231-231

Keyword(s):

Plastic Deformation ◽

Pure Iron ◽

Crystal Surfaces ◽

Size And Shape ◽

Slip Bands ◽

Wide Range ◽

Moderate Rate ◽

Rapid Deformation

The object of the investigation described in the present paper was to ascertain the manner in which wide variations in speed affect the mechanism of deformation in plastic metals. Iron was selected as the first metal for experiment, mainly because it is known that rapid deformation produced by shock is accompanied in this metal by special features, known as Neumann lines or lamellæ. When a piece of nearly pure iron, of suitable size and shape, with one face polished and etched, is subsequently subjected to plastic deformation at a moderate rate, the crystal surfaces, when examined under the microscope after deformation, show the well-known appearance of slip bands (1). The present experiments were undertaken in the first instance to ascertain whether the character, number and appearance of such slip bands would be appreciably affected by varying the rate of deformation over a wide range. For the sake of convenience, deformation by compression has been employed, the metal being used in the form of small rectangular prisms, measuring in some instances 0.44 inch by 0.44 inch in section by 0.7 inch in height.

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Aqueous phenol and ethylene glycol solutions in electrohydrodynamic liquid bridging

Open Chemistry ◽

10.2478/s11532-011-0029-3 ◽

2011 ◽

Vol 9 (3) ◽

pp. 391-403 ◽

Cited By ~ 11

Author(s):

Mathias Eisenhut ◽

Xinghua Guo ◽

Astrid Paulitsch-Fuchs ◽

Elmar Fuchs

Keyword(s):

Mass Transport ◽

Ethylene Glycol ◽

Bisphenol A ◽

Anodic Oxidation ◽

High Voltage ◽

Electrochemical Behavior ◽

Pure Water ◽

Passivation Layer ◽

Mass Transfers ◽

Electrophoretic Transport

AbstractThe formation of aqueous bridges containing phenol and ethylene glycol as well as bisphenol-A, hydrochinone and p-cresol under the application of high voltage DC (“liquid bridges”) is reported. Detailed studies were made for phenol and glycol with concentrations from 0.005 to 0.531 mol L−1. Conductivity as well as substance and mass transfers through these aqueous bridges are discussed and compared with pure water bridges. Previously suggested bidirectional mass transport is confirmed for the substances tested. Anodic oxidation happens more efficiently when phenol or glycol are transported from the cathode to the anode since in this case the formation of a passivation layer or electrode poisoning are retarded by the electrohydrodynamic (EHD) flow. The conductivity in the cathode beaker decreases in all experiments due to electrophoretic transport of naturally dissolved carbonate and bicarbonate to the anode. The observed electrochemical behavior is shortly discussed and compared to known mechanisms.

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