Summary In this work, Sr2+ dopant effects of Ba0.9Sr0.1TiO3 and La0.9Sr0.1CrO3‐δ doped‐perovskite nanoparticles on increasing proton conductivity, fuel cell performance, and mechanical and thermal stability of polybenzimidazole‐based nanocomposite membranes were studied. The Sr2+ dopant creates cation vacancies in Ba0.9Sr0.1TiO3 doped‐perovskite nanoparticles and oxygen vacancies in La0.9Sr0.1CrO3‐δ doped‐perovskite nanoparticles. The oxygen vacancies, which decrease columbic repulsion between protons and positive ions, have a more important role than the cation vacancies. They provide high surface area and high interfacial interaction between La0.9Sr0.1CrO3‐δ doped‐perovskite nanoparticles, phosphoric acid, and polybenzimidazole for proton transfer and increase the proton conductivity of the nanocomposite membranes. In addition, the results of relative humidity effects showed that the ordered arrangement of oxygen vacancies of the La0.9Sr0.1CrO3‐δ doped‐perovskite nanoparticles creates a specific pathway in the nanocomposite membranes for increasing proton transfer in the presence of relative humidity. Furtheremore, at phosphoric acid doping level of 13 mol phosphoric acid per monomer unit, proton conductivity of the nanocomposite membranes containing 8 wt.% La0.9Sr0.1CrO3‐δ doped‐perovskite nanoparticles was obtained as 126 mS cm‐1 at 180°C and 6% relative humidity. The nanocomposite membrane showed the best performance and the power density of 0.62 W cm‐2 at 180°C and 0.5 V.

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In this paper relations between 5S and pillars of Total Productive Maintenance (TPM) are explicated. In order to evaluate performance and effectiveness of 5S, we have benefited from a checklist by which status of implementation and execution of 5S in a foodstuff production factory in Iran has been studied. Furthermore, effects of this implementation on development and maturity of TPM is evaluated.

In this study, new nanocomposite membranes from sulfonated poly (ether ether ketone) (SPEEK) and proton-conducting Fe2TiO5 nanoparticles are prepared by the solution casting method. Sulfonated core–shell Fe2TiO5 nanoparticles are synthesized by redox polymerization. Therefore, 4-Vinyl benzene sulfonate (VBS) and 2-acrylamide-2-methyl-1-propane sulfonic acid (AMPS) are grafted on the surface of nanoparticles through radical polymerization. The different amounts of hybrid nanoparticles (PAMPS@Fe2TiO5 and PVBS@Fe2TiO5) are incorporated into the SPEEK matrix. The results show higher proton conductivity for all prepared nanocomposites than that of the SPEEK membrane. Embedding the sulfonated Fe2TiO5 nanoparticles into the SPEEK membrane improves proton conductivity by creating the new proton conducting sites. Besides, the nanocomposite membranes showed improved mechanical and dimensional stability in comparison with that of the SPEEK membrane. Also, the membranes including 2 wt% of PAMPS@Fe2TiO5 and PVBS@Fe2TiO5 nanoparticles indicate the maximum power density of 247 mW cm−2 and 226 mW cm−2 at 80 °C, respectively, which is higher than that of for the pristine membrane. Our prepared membranes have the potential for application in polymer electrolyte fuel cells.

PurposeThe purpose of this paper is to investigate the competitiveness of the Iranian leather value chain (LVC) and compare that with those of nine other countries including China, Pakistan, Turkey, Republic of Korea, Indonesia, Spain, Italy, Brazil and the USA. The results presented in the paper seek to assist in assessing the competitive performance of the LVC in Iran. In addition, based on Porter's diamond of competitive advantages, the aim is to provide recommendations to improve the competitive performance of the industry.Design/methodology/approachAn economic method, i.e. revealed comparative advantage (RCA), as a well‐known approach, is used to investigate the competitive performance of LVC in Iran. The LVC products analyzed in this research include hide, skin, leather manufacture, trunks and cases, and footwear. In addition, in order to investigate the factors which affect the low competitive performance, a questionnaire based on Porter's diamond of competitive advantages was designed and completed by researchers and practitioners working in the field of leather industry. Finally the reasons for low competitive performance of the industry are discussed.FindingsThe results reveal that the competitiveness of the Iranian LVC is low, compared with those of some other countries. China and Italy have superior comparative advantages in the period studied. The results also indicate that except one product, Iran has no comparative advantage in LVC industry. In addition, Iran has mainly focused on the upstream sector of LVC whereas China and Italy compete more in the downstream sector which offers more value added products. The results also reveal that among the elements studied, specialized factors, availability of capital, quality of demand and stability of macroeconomics highly influence the competitive performance of LVC in Iran. This is followed by subsequent recommendations on how best to improve the competitive performance of the industry.Originality/valueThe results of the investigation presented in this paper give an insight into the competitiveness of the LVC in Iran compared with nine other countries which play an important role in this industry in the world. The results also confirm that RCA can be used as an effective approach to assess the competitive performance of industries. Furthermore, reommendations provided in this paper assist in improving the competitive performance of the industry. In general, the findings should prove useful for both researchers and practitioners.