The electrical impedance behavior of gellan gum (GG), GG-carbon nanotube, and GG-carbon nanofiber hydrogel composites is reported. It is demonstrated that the impedance behavior of these gels can be modeled using a Warburg element in series with a resistor. Sonolysis (required to disperse the carbon fillers) does not affect GG hydrogel electrical conductivity (1.2 6 0.1 mS/cm), but has a detrimental effect on the gel's mechanical characteristics. It was found that the electrical conductivity (evaluated using impedance analysis) increases with increasing volume fraction of the carbon fillers and decreasing water content. For example, carbon nanotube containing hydrogels exhibited a six-to sevenfold increase in electrical conductivity (to 7 6 2 mS/cm) at water content of 82%. It is demonstrated that at water content of 95 6 2% the electrical behavior of multiwalled nanotube containing hydrogels transitions (percolates) from transport dominated by ions (owing to GG) to transport dominated by electrons (owing to the carbon nanotube network).

Following the 12 January 2010 Haiti earthquake, teams of students and faculty members from the United States and Haiti surveyed 170 reinforced concrete (RC) buildings in Port-au-Prince and Léogâne. This paper summarizes the survey results and compares them with results from a similar survey done after the 1999 earthquakes near Düzce, Turkey. The survey results demonstrate that the frequency of damage in RC buildings was higher in Haiti than in Turkey. This increased level of damage is consistent with practical screening criteria based on cross-sectional areas of building columns and walls. Based on these criteria, 90% of the structures surveyed in Haiti would have been classified as seismically vulnerable before the earthquake. Damage was more frequent in structures with captive columns. A two-tiered screening process is suggested to rapidly assess the vulnerability of scores of poorly built low-rise RC buildings in future earthquakes.

Purpose This study aims to investigate the effects of COVID-19 working arrangements on role stress, burnout and turnover intentions in public accounting professionals. Additionally, while all professionals have had to adapt to this rapid change in working environment, this paper explores whether the impact of this transition differs depending on demographic factors, namely, rank, gender, firm size and service line. Design/methodology/approach The authors survey 159 public accountants working in audit and tax on their perceptions of role stress, burnout and turnover intentions before COVID-19 and since. The survey used validated instruments from prior literature to capture these measures. Findings Results show that role stress, burnout and turnover intentions increased significantly since remote work began. Specifically, the rank of accountants significantly affects this association, with staff experiencing the most significant increases in role stress and burnout and seniors reporting significantly higher intentions to leave their current firms. Females experience a significant increase in feelings of emotional exhaustion and turnover intention, while males experience a significant increase in feelings of depersonalization and role overload. Finally, there is a positive association between firm size and burnout, with employees from national/midsize firms experiencing the largest increase in feelings of emotional exhaustion, reduced personal accomplishment and depersonalization. Originality/value Given that all prior research on role stressors, burnout tendencies and turnover intentions in the context of public accounting was conducted in the pre-COVID-19 work environment, this paper examines a timely and significant event that is likely to have a long-lasting impact on the way in which people work. As accounting firms seek to develop new working models and promote well-being among their employees, they should take note of the findings of this study that gender, rank and firm size result in differential impacts on role stress, burnout and turnover intentions.

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