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This study aims to investigate the fatigue crack propagation behavior of SiC particle-reinforced 2124 Al alloy composites under constant amplitude axial loading at a stress ratio of R = 0.1. For this purpose, it is performed experiments and comparatively analyze the results by producing 5, 10, 15 Vol.% SiCp-reinforced composites and unreinforced 2124 Al alloy billets with powder metallurgy (PM) production technique.

With the PM production technique, SiCp-reinforced composite and unreinforced 2124 Al alloy billets were produced at 5%, 10%, 15% volume ratios. After the produced billets were extruded and 5 mm thick plates were formed, tensile and fatigue crack propagation compact tensile (CT) samples were prepared. Optical microscope examinations were carried out to determine the microstructural properties of billet and samples. To determine the SiC particle–matrix interactions due to the composite microstructure, unlike the Al alloy, which affects the crack initiation life and crack propagation rate, detailed scanning electron microscopy (SEM) studies have been carried out.

Optical microscope examinations for the determination of the microstructural properties of billet and samples showed that although SiC particles were rarely clustered in the Al alloy matrix, they were generally homogeneously dispersed. Fatigue crack propagation rates were determined experimentally. While the highest crack initiation resistance was achieved at 5% SiC volume ratio, the slowest crack propagation rate in the stable crack propagation region was found in the unreinforced 2124 Al alloy. At volume ratios greater than 5%, the number of crack initiation cycles decreases and the propagation rate increases.

As a requirement of damage tolerance design, the fatigue crack propagation rate and fatigue behavior of materials to be used in high-tech vehicles such as aircraft structural parts should be well characterized. Therefore, safer use of these materials in critical structural parts becomes widespread. In this study, besides measuring fatigue crack propagation rates, the mechanisms causing crack acceleration or deceleration were determined by applying detailed SEM examinations.

This study’s purpose is twofold: First, to investigate the relationship between managerial competences and Integrated Reporting (IR) practices; Second, to test whether all the managerial competences attributes are significantly related to IR practices.

This study adopts a correlational research design, and is also cross-sectional. Data were collected using a questionnaire survey of 188 manufacturing firms in Uganda. Data were analyzed with the help of the Statistical Package for Social Sciences.

The study finds that significant associations between managerial competences of knowledge and experience exist with IR practices except for skills. However, experience is the most significant predictor of IR practices. This experience is manifest, among others, in the managers’ ability to get the word out to the public including why the public should be proud of what the company does and about what the company offers and works to make it better.

This study did not control governance variables and yet governance and IR are inextricably associated. Future research should aim at testing the efficacy of investing in governance aspects potentially improving IR. This is because Environmental, Social and Governance investing is predicted to make capitalism work better and deal with the grave threat posed by climate change. The study also focuses on manufacturing firms, and these results may be only applicable to the manufacturing firms in Uganda. More research is therefore needed to further understand the effect of managerial competence attributes on IR in manufacturing firms in other contexts. Well, the results imply that more experienced managers are better placed to embrace IR practices than their less experienced counterparts.

The authors find that managerial experience explains IR practices more than competences and this makes intuitive sense since, for example, better experiential communication potentially minimizes the challenges such as lack of comparability, difficulty in communicating entity-specific information, information not available in a usable format and data errors normally encountered by IR (especially electronic) users. Hence, this study enhances our understanding of the role of managerial competences in the improvement of IR practices using perceptions of report preparers from a developing country where IR is voluntary and where the size of the stock market is small.

The low carbon steel used in industrial water conveying pipes in the Dora refinery is corroded. This study aims to reduce corrosion rate in these pipes by using green inhibitor extracted from dill plant. This inhibitor is sustainable environmentally.

The inhibitor extracted from the dill plant was added at different temperatures (25, 40, 60 and 80°C) and at a fixed concentration of 1,400 ppm, as the best protection was obtained at this concentration. The study was carried out under the same conditions using a polarization technique and scanning electron microscope.

From the results obtained from the polarization curves, it was found that the inhibition efficiency was 92.12% at a concentration of 1,400 ppm and a temperature of 20°C. Potentiodynamic curves showed that both cathodic and anodic reactions were affected by the addition of the inhibitor, indicating that the used inhibitor acted as a mixed type inhibitor, which means that the addition of these inhibitors to the industrial water reduced the anodic dissolution of iron and also retarded the cathodic hydrogen evolution reaction. This reveals that the inhibition mechanism is of the mixed type with a predominant anodic reaction. The results of the fourier transform infrared test indicated that the dill plant contained different chemical bonds (C–H, C = O, S = O, N–O and C–N) that were included in the construction of the barrier layer to protect the steel surface from corrosion.

The dill plant is abundant in nature, its cost is low and its extraction is very easy. It can be used as an environmentally friendly inhibitor to reduce the rate of corrosion in water-carrying pipes used in oil refineries because it contains effective groups (aromatic rings) that combine with metal atoms to form strong bonds that stick to the surface of the metal, which protect it from the attack of the corrosive medium.

This paper aims to study the corrosion inhibition behavior of imidazopyridine and its three derivatives on brass.

The authors performed weight loss experiments, electrochemical experiments including the polarization curve and electrochemical impedance spectrum, corrosion morphology observation using scanning electron microscope (SEM) and atomic force microscope (AFM) and surface composition analysis via X-ray photoelectron spectroscopy (XPS) to analyze the corrosion inhibition behavior of imidazopyridine and its three derivatives on brass by using quantum chemical calculation (Gaussian 09), molecular dynamics simulation (M-S) and Langmuir adsorption isotherm.

According to the results, imidazole-pyridine and its derivatives were found to be modest or moderately mixed corrosion inhibitors; moreover, they were spontaneously adsorbed on the metal surface in a single-layer, mixed adsorption mode.

The corrosion inhibition properties of pyrazolo-[1,2-a]pyridine and its derivatives on brass in sulfuric acid solution were analyzed through weight loss and electrochemical experiments. Moreover, SEM and AFM were simultaneously used to observe the corrosion appearance. Furthermore, XPS was used to analyze the surface. Then, Gaussian 09 and M-S were combined along with the Langmuir adsorption isotherm to investigate the corrosion inhibition mechanism of imidazole-[1,2-a]pyridine and its derivatives.