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This paper aims to evaluate the bioremediation [chemical oxygen demand (COD) and color removal] of the effluent from the cardboard recycling industry in Yazd, central province of Iran, using mixed fungal culture.

First, the effluent samples from the cardboard recycling industry were cultured on potato dextrose agar medium to isolate native fungal colonies. The grown colonies were then identified using morphological macroscopic and microscopic characteristics to choose the dominant fungi for bioremediations. The mixed cultures of Aspergillus niger, Aspergillus flavus and Penicillium digitatum were finally used for bioremediation experiments of the cardboard recycling industry. A suspension containing 1 × 10⁶ CFU/ml of fungal spores was prepared from each fungus, separately and their homogenous mixture. Sewage samples were prepared and sterilized and used at 25%, 50% and 90% dilutions and pH levels of 5, 7 and 8 for bioremediation tests using mixed fungal spores. Following that, 10 ml of the mixed fungal spores were inoculated into the samples for decolorization and COD removal and incubated for 10 days at 30°C. The amount of COD removal and decolorization were measured before incubation and after 3, 6 and 10 days of inoculation. In this research, the color was measured by American Dye Manufacturer Institute and COD by the closed reflux method. The results of the present study were analyzed using SPSS 21 statistical software and one-way ANOVA tests at p-value < 0.05.

The results of this research showed that the mean decolorization by mixed fungal culture over 10 days at pH levels of 5, 7 and 8 were 44.40%, 45.00% and 36.84%, respectively, and the mean COD removal efficiency was 71.59%, 73.54% and 16.55%, respectively. Moreover, the mean decolorization at dilutions of 25%, 50% and 90% were 45.00%, 31.93% and 30.53%, respectively, and the mean COD removal efficiency was 73.54%, 62.38% and 34.93%, respectively. Therefore, the maximal COD removal and decolorization efficiency was obtained at dilution of 25% and pH 7.

Given that limited studies have been conducted on bioremediation of the effluent from the cardboard recycling industry using fungal species, this research could provide useful information on the physicochemical properties of the effluent in this industry.

The inhibitive action of triazoles and surfactants on the corrosion of carbon steel has been studied using the weight loss method and electrochemical studies. Results obtained show that these organic compounds are very good inhibitors. Potentiodynamic polarisation studies clearly reveal the type of inhibitor. The corrosion parameters such as corrosion current (i_corr), corrosion potential (E_corr), inhibition efficiency (IE), corrosion rate, and activation energy (E_a) were calculated at different temperatures ranging from 303 to 333 K. The adsorption of triazole compounds on carbon steel surface obeyed Langmuir's adsorption isotherm.

This paper aims to investigate the protection efficiency of a thin film of electrochemically synthesized conducting polymers, such as poly m‐toluidine, poly N‐methyl aniline, and its copolymer, poly (aniline‐co‐N‐methyl aniline) (PANINMA), on plain carbon steel in 0.1 M HCl. It also attempts to compare the protection efficiency of these compounds with polyaniline (PANI)‐coated carbon steel.

The green coloured and adherent coatings were obtained by cyclic voltammetry during sequential scanning of the potential region between −0.6 and 1.6 V at a scan rate of 10 mVs⁻¹. Potentiodynamic polarization measurement (DC) was used to obtain an estimate of the corrosion rate and protection efficiency for these electrodeposited polymers on the carbon steel. Scanning electron micrographs (SEM) also were obtained to characterize the deposited coatings.

It was observed that these polymer coatings showed better protection efficiency than the PANI coating. Of the compounds studied, the copolymer PANINMA coating showed higher protection efficiency than other coatings. The SEM observations revealed that the compact continuous dense morphology of PANINMA provided better protection than other coatings.

This paper explains the protection efficiency of the substituted and copolymer coatings of PANI on carbon steel.

The purpose of this paper is to review the literature on maintenance optimization models and associated case studies. For these optimization models critical observations are made.

The paper systematically classifies the published literature using different techniques, and also identifies the possible gaps.

The paper outlines important techniques used in various maintenance optimization models including the analytical hierarchy process, the Bayesian approach, the Galbraith information processing model and genetic algorithms. There is an emerging trend towards uses of simulation for maintenance optimization which has changed the maintenance view.

A limited literature is available on the classification of maintenance optimization models and on its associated case studies. The paper classifies the literature on maintenance optimization models on different optimization techniques and based on emerging trends it outlines the directions for future research in the area of maintenance optimization.

The paper provides many references and case studies on maintenance optimization models and techniques. It gives useful references for maintenance management professionals and researchers working on maintenance optimization.

This paper aims to achieve an optimal design for distribution transformers considering cost and power losses. Particle swarm optimization (PSO) algorithm is used as an optimization tool for minimizing the objective functions of design procedure which are cost and electrical and iron losses.

In this paper, distribution transformer losses are considered as operating costs. Also, transformer construction cost which depends on the amount of iron and copper in the structure is assumed as its initial cost. In addition, some other important constraints such as appropriate ranges of transformer efficiency, voltage regulation, temperature rise, no-load current, and winding fill factor are investigated in the design procedure. The PSO algorithm is applied to find optimum amount of needed copper and iron for a typical distribution transformer. Moreover, transformer impedance considered as a constraint to achieve an acceptable voltage regulation in the design process.

It is shown that the proposed design procedure provides a simple and effective approach to estimate the flux and current densities for minimizing the active part cost and active power losses which means reduction in amount of transformer total owning cost (TOC).

The methodology advances a proposal for reducing distribution transformers costs using PSO algorithm. The approach considers the aforementioned constraints and TOC to minimize the active part cost and maximize the efficiency. It is demonstrated that a designed transformer will not be optimum when the transformer losses over years are not considered in design procedure. Finally, the results prove the effectiveness of the proposed procedure in designing cost-effective distribution transformers from its initial cost until its whole life.

To investigate the capability of a series of nitrogen‐based heterocyclic organic compounds in inhibiting corrosion of iron in HCl and elucidate the dominant active form of the applied compounds during the adsorption process to explore the mechanism of their action.

The tested compounds were pyrimidine containing compounds, which were selected, based on molecular structure considerations. Gravimetric method has been applied with various electrochemical techniques (polarisation resistance, polarisation curves and electrochemical impedance spectroscopy) to investigate inhibition efficiency and mechanism.

The inhibiting action of the investigated pyrimidine containing compounds depends primarily on their concentration and molecular structure. These compounds act as mixed type inhibitors and function via adsorption on the surface, which follows Frumkin adsorption isotherm. The inhibition by the tested pyrimidine derivatives could be attributed to their chemisorption on the metal surface forming donor/acceptor type of bond between the inhibitor molecules and the vacant d orbitals of the surface iron atoms. Contribution from electrostatic adsorption, via interaction between the protonated form of the inhibitor and the charged metal surface, is also possible.

The applied inhibitors were tested in the presence of chloride ions as a corrosive medium. Whether these inhibitors will function well in the presence of other ions that are typically present in natural corrosive environment is unknown.

This paper provides useful information regarding inhibition effect of pyrimidine and series of its derivatives. The outcome of this work contributes to better understanding of the mechanism of inhibition by this class of N‐based heterocyclic organic compounds.

This paper aims to study the corrosion inhibition of Methyl 2-(benzamido)-2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate (MBPTA) and Methyl 2-(benzamido)-2-(4-p-tolyl-1H-1,2,3-triazol-1-yl) acetate (MBTTA) in 1 M H2SO4 solution at 25 °C.

The authors have used weight loss measurements, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, FT-IR, quantum chemical calculations and scanning electron microscopy (SEM) techniques.

The polarization measurements indicate that both compounds are mixed type inhibitors, and that MBTTA is more effective than MBPTA. The effect of temperature on the corrosion behavior using optimal concentration of MBTTA and MBPTA was studied in the temperature range 298-328 K. SEM was used to examine the morphology of the metal surface. Thermodynamic parameters were calculated and discussed. Monte Carlo simulations were applied to lookup for the most stalls configuration and adsorption energy for the interaction of inhibitors on Fe (1 1 1) interface. The difference in inhibition efficiencies between the two organic inhibitors can be clearly explained in terms of frontier molecular orbital theory.

The authors report on the comparative inhibiting effect of two new 1,4-disubstituted 1,2,3-triazoles, namely Methyl 2-(benzamido)-2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate (MBPTA) and Methyl 2-(benzamido)-2-(4-p-tolyl-1H-1, 2, 3-triazol-1-yl) acetate (MBTTA) on mild steel corrosion in 1 M H₂SO₄ solution.

The cycloaddition of cyclic nitrone1‐pyrroline‐1‐oxide with 1‐dodecene and 1‐hexadecene afford a bicyclic (isoxazolidines). These isoxazolidines were tested for corrosion inhibition of carbon steel in 1N H₂SO₄ in the 30‐60°C temperature range by gravimetric and electrochemical methods. The compound isoxazolidines exhibited excellent inhibition efficiency in the acidic corrosion environment. The presence of heteroatoms such as N and O induce greater adsorption of the inhibitor molecules onto the surface of carbon steel and the long hydrocarbon chains ensure coverage of the metal surface. The values of activation energy and free energy of adsorption indicated the physical nature of the adsorption on the surface of the carbon steel. Thermodynamic parameters were determined for the adsorption process (ΔG_ads^o, ΔH_ads^o, ΔS_ads^o), and kinetic parameters for the metal dissolution (or hydrogen evolution) reaction in the presence of the isoxazolidines. The adsorption of inhibitors on the metal surface was found to obey the Langmuir adsorption isotherm. The isoxazolidines were found to be mixed‐type inhibitors. The isoxazolidine which had a tetradecyl hydrophobe was found to be a better inhibitor than was the decyl analogue.

This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely, 1-((1-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazole (TTB) on the corrosion of mild steel in aerated 1 M H₂SO₄.

The authors have used weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, FT-IR studies, scanning electron microscopy analysis and energy dispersive X-ray (EDX) spectroscopy techniques.

It is found that, in the working range of 298-328 K, the inhibition efficiency of TTB increases with increasing concentration to attain the highest value (92 per cent) at 2.5 × 10⁻³ M. Both chemisorption and physisorption of TTB take place on the mild steel, resulting in the formation of an inhibiting film. Computational methods point to the imidazole and phenyl ring as the main structural parts responsible of adsorption by electron-donating to the steel surface, while the triazol ring is responsible for the electron accepting. Such strong donating–accepting interactions lead to higher inhibition efficiency of TTB in the aqueous working system.

This work is original with the aim of finding new acid corrosion inhibitors.

Copper and its alloys are widely used in industries because of their good resistance to corrosion and are often used in cooling water systems. Brass has been widely used for shipboard condensers, power plant condensers and petrochemical heat exchangers. Brass is susceptible to the corrosion process known as dezincification by means of which brass looses its valuable physical and mechanical properties leading to failure of structure. The aim of this investigation was to control the dezincification of brass in 3 per cent NaCl solution using benzotriazole (BTA) derivatives.

BTA derivatives namely 1‐hydroxymethylbenzotriazole (HBTA) and N,N‐dibenzotriazol‐l‐ylmethylamine(ABTA) were synthesised and their inhibition behaviour on brass in 3 per cent NaCl solution was investigated by the weight‐loss method, potentiodynamic polarisation, electrochemical impedance and solution analysis techniques. The morphology of the brass after corrosion in the presence and absence of the BTA derivatives was examined using scanning electron microscopy (SEM).

Potentiodynamic polarisation studies showed that the BTA derivatives investigated were mixed type inhibitors, inhibiting the corrosion of brass by blocking the active sites of the brass surface. Changes in the impedance parameters (charge transfer resistance and double layer capacitance) were related to the adsorption of BTA derivatives on the brass surface, leading to the formation of a protective film. Solution analysis revealed that the BTA derivatives excellently controlled the corrosion of brass. SEM micrographs showed the formation of compact surface film on the brass surface in the presence of inhibitors, thereby providing better corrosion inhibition.

Contributes to research on corrosion protection for copper and its alloys.