Electrochemical corrosion protection of neat and zinc phosphate modified epoxy coating: A comparative physical aging study on Al alloy 6101.

Optimizing the pigment volume concentration of zinc phosphate pigments can protect Al alloy 6101 from alkaline media. Additionally, zinc phosphate pigments form a shielding film on the substrate and facilitate stopping the penetration of aggressive corrosion ions. The efficiency of eco-friendly zinc phosphate pigments is almost 98% during the corrosion analysis. A comparative study of physical aging of neat epoxy and Zinc Phosphate (ZP) pigment-modified epoxy coatings on Al alloy 6101 was conducted in Xi'an, China, for one year in all four seasons, where in summer for 3 months, results degraded more due to high UV radiation and humidity; it is found that peeling force of ZP pigments modified epoxy coatings is 50% higher of than that of the neat epoxy coatings though both peel-off adhesion strength and scratch test visibility decreased in both coatings; The electrochemical resistance of ZP pigments modified epoxy coatings is about 30% higher of than that of neat epoxy coatings, the corrosion rate of ZP pigments modified epoxy coatings is about 70% lower of than that of neat epoxy coatings, moreover the gloss retention is 20% higher in the modified epoxy; Optical surface observation of the coatings showed that the ZP modified epoxy coating could effectively restrict the crack and shrinkage in coatings after aging experimentation in the natural environment.

Determinants and implications of environmental practices for waste management and the minimization in the construction industry: a case study of Pakistan.

The construction projects and activities generate waste materials, which impose negative impacts on the environment and contribute towards environmental degradation. In this regard, the implementation of environmental practices (EPs) can play a vital role in reducing the environmental risks associated with waste materials from construction projects. Based on this hypothesis, the present survey study was conducted to assess the effectiveness of different EPs in reducing environmental risks associated with waste materials from construction firms (n = 159) operating in Pakistan. Organizational and government support, regulatory pressure, and economic and environmental performance were among the main determinants of EPs studied in the present study. The partial least squares technique was used for the data collection, assessment, and prediction of the results based on the hypothesis testing for a range of determinants. Compose reliability analysis of determinants showed that all items gave a value of 0.7, which is a clear indication of the reliability of each determinant in the formation of the hypothesis. From all eight hypotheses, H1 (0.475), H4 (0.217), H6 (0.114), H7 (0.210), and H8 (0.149) hypotheses with size effect in parentheses were acceptable due to their positive construction with EPs, while H2, H3, and H5 hypothesis did not show the significant effect with size effect values lower than 0.1. The study demonstrated that current environmental regulations and governing bodies in Pakistan are not sufficiently effective and strict to implement environmental regulations. In this regard, regulatory pressure is necessary to promote EPs along with increasing stakeholders' awareness. Overall, the implementation of EPs not only prepares construction firms to deal with the pressure exerted by regulations and customers but also enhances the environmental and economic performance of construction firms.

Gray relational analysis for the effect of nano-drug features on drug absorption / 药学学报

Gray relational analysis is employed to analyze the effects of nano-drug features on phagocytosis of macrophages, including zeta potential, shape factor and scale size of drug particle, the correlation among such factors and macrophage cell is calculated. The results showed that the internalization processe is affected significantly by the zeta potential of the drug in the process of phagocytosis of macrophages, followed by the impact particle shape, and the effect of particle scale behaves relatively small.

Effect of temperature, chloride ions and sulfide ions on the electrochemical properties of 316L stainless steel in simulated cooling water / 药物分析学报

The influence of temperature, chloride ions and sulfide ions on the anticorrosion behavior of 316L stainless steel in simulated cooling water was studied by electrochemical impedance spectroscopy and anodic polarization curves. The results show that the film resistance increases with the solution temperature but decreases after 8 days' immersion, which indicates that the film formed at higher temperature has inferior anticorrosion behavior; Chloride ions and sulfide ions have remarkable effects on the electrochemical property of 316L stainless steel in simulated cooling water and the pitting potential declines with the concentration of chloride ions; the passivation current has no obvious effect; the rise of the concentration of sulfide ions obviously increases the passivation current, but the pitting potential changes little, which indicates that the two types of ions may have different effects on destructing passive film of stainless steel. The critical concentration of chloride ions causing anodic potential curve's change in simulated cooling water is 250 mg/L for 316 L stainless. The effect of sulfide ions on the corrosion resistance behavior of stainless steel is increasing the passivation current density Ip. The addition of 6mg/L sulfide ions to the solution makes Ip of 316 L increase by 0.5 times.