Search results

The purpose of this paper is to study the effect of current-carrying condition on the electrochemical process and atmospheric corrosion behavior of the commercial aluminum alloys.

Potentiodynamic polarization tests were performed to study the electrochemical process of the aluminum alloys. Salt spray tests and weight loss tests were carried out to study the atmospheric corrosion behavior. The corrosion morphology of the alloys was observed, and the products were analyzed.

The corrosion process of four aluminum alloys was accelerated in the current-carrying condition. Moreover, the acceleration effect on A2024 and A7075 was much stronger than that on A1050 and A5052. The main factors would be the differences in microstructure and corrosion resistance between these alloys. As the carried current increased, the corrosion rate and corrosion current density of the aluminum alloys gradually increased, with the protection of the corrosion product film decreasing linearly.

This is a recent study on the corrosion behavior of conductors under current-carrying condition, which truly understands the corrosion status of power grid materials. Relevant results provide support for the corrosion protection and safe service of aluminum alloy in power systems.

The purpose of this study is to assess the impact of rising food prices on food demand and nutrient intake among rural–urban migrants and whether such impact varies across income classes.

Using data from the China Health and Nutrition Survey (CHNS), this study adopts a quadratic almost ideal demand system (QUAIDS) for food demand elasticity and an indirect estimation method for nutrient elasticity to investigate the effects of rising food prices on food demand and nutrient intake among rural–urban migrants.

The estimated results indicate that an increase in the price of pork alone would lead to a larger reduction in most nutrients among rural–urban migrants than other single targeted food group, and a simultaneous rise in the price of all food groups would have a remarkably adverse effect on the nutritional status of rural–urban migrants in comparison to the nutritional effects of a rise in one targeted food group. In addition, the nutritional effects of food prices across income classes show that the nutritional status is particularly vulnerable to rising food prices among low-income rural–urban migrants.

This paper focuses on analyzing the impact of rising food prices on the nutritional status of rural–urban migrants, a topic that is very limited in the literature. This study provides a fresh look at the effect of volatile food prices on food demand and nutrient intake among rural–urban migrants. The results indicate that income growth would have a remarkable positive effect on nutrient intake for rural–urban migrants, especially for low-income rural–urban migrants. However, an increment in nutrients due to a growth in income would not be far from enough to cover the reduction in nutrients as a result of a simultaneous rise in price of all the studied food categories at the same rate.

Previous research has little specific guidance on how to improve large infrastructures’ risk analysis. This paper aims to propose a practical risk analysis framework across the project lifecycle with Bayesian Networks (BNs).

The framework includes three phases. In the qualitative phase, primary risks were identified by literature reviews and interviews; questionnaires were used to determine key risks at each project stage and causal relationships between stage-related risks. In the quantitation, brainstorming and questionnaires, and techniques of ranked nodes/paths, risk map and Bayesian truth serum were adopted. Then, a BN-based risk assessment model was developed, and risk analysis was conducted with AgenaRisk software.

Twenty key risks across the lifecycle were determined: some risks were recurring and different risks emerged at various stages with the construction and feasibility most risky. Results showed that previous stages’ risks significantly amplified subsequent stages’ risks. Based on the causality of stage-related risks, a qualitative model was easily constructed. Ranked nodes/paths facilitated the quantification by requiring less statistical knowledge and fewer parameters than traditional BNs. As articulated by a case, this model yielded very simple and easy-to-understand representations of risks and risk propagation pathways.

Rare research has developed a BN risk assessment model from the perspective of project stages. A structured model, a propagation network among individual risks, stage-related risks, and the final adverse consequence, has been designed. This research provides practitioners with a realistic risk assessment approach and further understanding of dynamic and stage-related risks throughout large infrastructures’ lifecycle. The framework can be modified and used in other real-world risk analysis where risks are complex and develop in stages.