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This paper aims to investigate the corrosion resistance of two types of coatings – one is ceria sol coating and the other is ceria sol coating modified by ZnO nanoparticles on 7075 aluminum alloy in 3.5% NaCl solution.

Aluminum alloys were dipped into ceria sol and ceria sol modified by ZnO nanoparticles separately and removed after 10 min from the solutions and dried at 110°C for 30 min and heated at 500 °C for 30 min to form the coatings. The coatings have been characterized by using field emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The EIS tests were performed in a corrosive solution of 3.5% NaCl.

The results showed that the coating of ceria sol modified by ZnO nanoparticles has higher corrosion resistance than the ceria sol coating and the bare sample. Also, the best efficiency is related to aluminum sample immersion after 1 h in NaCl corrosive solution for coating modified by ZnO nanoparticles.

In this research, the modification of ceria sol coating by ZnO nanoparticles had an effect on improving the corrosion behavior of aluminum alloy. It is also understood that modification of coatings is an effective parameter on corrosion resistance.

The purpose of this investigation is to study the corrosion behavior of iron and aluminum in HCl and NaOH media by means of theoretical and experimental approaches.

For theoretical investigations, the quantum chemical calculation was performed. In this regard, the adsorption of OH⁻ and Cl⁻ on iron and aluminum surfaces was investigated. Furthermore, the natural bond orbital for the direction and magnitude of charge transfer interactions were calculated. In addition, the electrochemical evaluations based on potentiodynamic experiments were carried out.

The quantum chemical calculation results showed that the charge transfer from OH⁻ to the iron surface is more than that from Cl⁻, and also the charge transfer from Cl⁻ is more than that from OH⁻ to aluminum cluster. Furthermore, these anions donate more electrons to the iron cluster than to the aluminum cluster. The experimental data showed that the rate of corrosion of iron in 1.0M NaOH solution was less than in 1.0M HCl solution. The corrosion of aluminum in HCl solution was less than that in NaOH solution. The rate of corrosion of iron in both solutions was less than that of aluminum.

The findings of this paper indicate that calculations based on the natural bond orbital analysis of the charge transfer rates from OH⁻ and Cl⁻ to the iron or aluminum surfaces, and their comparison with experimental results, exhibited excellent agreement.

The purpose of this paper was to study the corrosion resistance of AA2024 alloy using surfactant-modified halloysite nanocapsules capable of holding benzotriazole (BTA) as the corrosion inhibitor and discharging it into the solution.

The effect of surfactant shells was studied by surfactant-modified halloysite nanotubes fabricated through assembly of two types of cationic surfactants. The zeta potential and size distribution measurements were performed using a Zetasizer Nano. The concentration of BTA during release into the solution was detected by using a UV–vis spectrophotometer. The anti-corrosion activity of nanocapsules as free agents with respect to the AA2024 alloy was investigated using the potentiodynamic scan (PDS) method. An epoxy resin doped with nanocapsules was used as an anti-corrosion coating deposited on the AA2024 alloy. The corrosion protection performance of coatings was studied by using the electrochemical impedance spectroscopy (EIS) method.

The results indicate that the release of the inhibitor from nanocapsules depends on the surfactant shell components. The PDS results confirmed the feasibility of developing “smart” corrosion protection by inhibitor-loaded nanocapsules. The results of EIS measurements showed that the coating with the nanocapsules exhibited enhanced corrosion protection in comparison with the undoped coating.

The findings of this paper indicate that surfactant-modified halloysite nanocapsules can be added to epoxy resin coatings to improve their corrosion protective properties for the AA2024 alloy.

The purpose of this paper was to study the corrosion resistance of water-based sol-gel coatings containing titania nanoparticles doped with organic inhibitors for corrosion protection of AA2024 alloy.

The coatings were obtained using tetraethylorthosilicate, 3-glycidoxypropyltrimethoxysilane, titanium (IV) tetrapropoxide and poly(ethylene imine) polymer as cross-linking agents. As corrosions inhibitors, 2-mercaptobenzoxazole and salicylaldoxime were incorporated into the sol-gel for the improvement of the corrosion resistance. The corrosion protection performance of coatings was studied using the potentiodynamic scan and the electrochemical impedance spectroscopy (EIS) methods. Atomic force microscopy was used to investigate surface morphology of the coatings.

The results indicated that doping the sol-gel coatings with inhibitors leads to improvement of the corrosion protection. The comparison of doped coatings confirmed that corrosion protection performance of the sol-gel coatings doped with 2-mercaptobenzoxazole was better than for the sol-gel coatings doped with salicylaldoxime. Also the EIS results verified self-healing effects for the sol-gel coatings doped with 2-mercaptobenzoxazole.

This paper indicates 2-mercaptobenzoxazole and salicylaldoxime can be added as corrosion inhibitors to sol-gel coatings to improve their corrosion protective properties for AA2024 alloy.

Meeting the patients' requirements as customers of the health care sector is crucially important as a social responsibility. According to the resource constraints, only an efficient utilisation of health services can provide that purpose. This study aims to develop a quantitative assessment framework for radiology centres as a vital section in healthcare to translate the patients' requirements into service quality specifications. This would help to achieve quality improvement by emphasising the voice of customers.

A literature review is conducted to specify the service quality criteria and the patients' requirements related to healthcare and hospitals. Based on the experts' opinions, these criteria and requirements are later customised for the radiology centres. Moreover, the requirements are categorised into five dimensions of SERVQUAL. The interrelations between service elements are also determined through expert group consensus using Pearson correlation. Afterwards, by applying the QFD method, the relations between the requirements and criteria are explored. Additionally, a customer satisfaction survey is executed in Tehran public hospitals to prioritise these requirements and provide an importance-satisfaction analysis.

Based on the result of the case study, service elements are prioritised for improvement, and practical suggestions are provided using the Delphi technique for quality improvement. In addition, a cause-and-effect diagram is presented to highlight the improvement area and provide enhancement suggestions.

This study is the first empirical attempt to benefit from the VOC in evaluating and enhancing the quality of service delivered to radiology patients. In doing so, the study applies a hybrid approach of QFD and SERVQUAL as well as other tools to highlight the improvement area and provide enhancement suggestions. The findings can be readily used by the practitioners.

Two-stage production systems including a processing shop and an assembly stage are widely used in various manufacturing industries. These two stages are usually studied independently which may not lead to ideal results. This paper aims to deal with a two-stage production system including a job shop and an assembly stage.

Some exact methods are proposed based on branch and bound (B&B) approach to minimize the total completion time of products. As B&B approaches are usually time-consuming, three efficient lower bounds are developed for the problem and variable neighborhood search is used to provide proper upper bound of the solution in each branch. In addition, to create branches and search new nodes, two strategies are applied including the best-first search and the depth-first search (DFS). Another feature of the proposed algorithms is that the search space is reduced by releasing the precedence constraint. In this case, the problem becomes equivalent to a parallel machine scheduling problem, and the redundant branches that do not consider the precedence constraint are removed. Therefore, the number of nodes and computational time are significantly reduced without eliminating the optimal solution.

Some numerical examples are used to evaluate the performance of the proposed methods. Comparison result to mathematical model (mixed-integer linear programming) validates the performance accuracy and efficiency of the proposed methods. In addition, computational results indicate the superiority of the DFS strategy with regard to CPU time.

Studies about the scheduling problems for two-stage production systems including job shop followed by an assembly stage traditionally present approximate method and metaheuristic algorithms to solve the problem. This is the first study that introduces exact methods based on (B&B) approach.

The purpose of this paper is to extent the theory of planned behaviour (TPB), when extended by self-identity and religious commitment (RC), and is able to predict Muslim consumers’ willingness to pay (WP) for certified halal food.

A survey of 277 Muslim consumers in Malaysia was conducted and the cross-sectional data were analysed using the partial least squares technique.

Attitude (ATT) and religious self-identity (RSI) were found to have a positive impact on WP for certified halal food. Additionally, RC has a positive effect on ATT and RSI and has a positive moderating effect on the relationship between perceived behavioural control and WP.

The findings can benefit halal food companies by offering an insight into the willingness of Muslim consumers to pay for certified halal food.

The findings contribute to the research on halal foods by illustrating the factors that determine Muslim consumers’ WP for certified halal food. This study also extends the understanding of the TPB to the halal food context.