Differences in Male Climacteric Symptoms and Lifestyle Depending on the Duration of Working among Rotating Night Shift Workers

Background: There are various health problems in rotating shift workers. There have been few studies on the associations of male climacteric symptoms with duration of working and lifestyle. Objective: The aim of this study was to determine the differences in male climacteric symptoms depending on the number of working years and to determine whether lifestyle habits differ depending on the number of working years in rotating shift workers. Methods: We collected participant’s data from the manufacturing companies in Japan during the period from March to May in 2017. We conducted a self-administered questionnaire survey in 1561 male rotating night shift workers. Male climacteric symptoms were evaluated by using the Aging Males’ Symptoms (AMS) rating scale. We analyzed 636 rotating shift workers aged over 40 years old whose all AMS data was collected. Results: A significant difference in psychological AMS score was found between men who had worked for 10 - 19 years (9.4 ± 3.9) and men who had worked for more than 40 years (7.6 ± 3.0) (p = 0.011). Sexual functional AMS score significantly differed depending on the number of working years (less than 10 years: 8.1 ± 3.9, 10 - 19 years: 9.8 ± 4.1, 20 - 29 years: 7.9 ± 3.3, 30 - 39 years: 9.3 ± 3.5, more than 40 years: 9.3 ± 3.5) (p < 0.001). The proportion of workers with a balanced meal intake was significantly lower in men who had worked for less than 10 years and the proportions of such workers were significantly higher in men who had worked for 10 - 19 years and for more than 40 years. The proportions of men who did not drink alcohol were high in men who had worked for less than 10 years and 20 - 29 years and low in men who had worked more than 30 years. Conclusion: Psychological AMS score and sexual functional AMS score are significantly different among the 5 groups according to the number of working years on rotating shift. In addition, well-balanced diet on day shift and reduction of alcohol drinking is a related-factor for long-term rotating night shift workers.

Ethanol based foamed asphalt as potential alternative for low emission asphalt technology

Foamed asphalt typically relies on water as a foaming agent because water becomes gaseous at elevated temperatures, generating numerous tiny bubbles in the asphalt and causing spontaneous foaming. In this study, ethanol was used as a potential alternative to water as a foaming agent. Ethanol is expected to be a physical blowing agent in the same manner as water, except it requires less energy to foam due to its 78 ℃ boiling point. This study compares the performance of water and ethanol as foaming agents through the measurements of rotational viscosity, the reduction in temperature during foaming, and volatile loss. The ethanol-foamed asphalt binders were prepared at 80 ~C and 100 ~C, while the water-foamed asphalt binders were prepared at 100 ~C and 120 ~＇C. Additionally, the rolling thin film oven （RTFO） was used to generate short-term aging of the foamed asphalt binders. A rotational viscometer was used to determine the viscosity of the asphalt binders at 80 ~C, 100 ~C, 120 ~C, 140 ~C, and 160 ~C. Overall, ethanol can function in the same manner as water but requires less energy to foam. It is proven based on the smaller drop in temperature of the asphalt binder foamed using ethanol compared with that prepared with water. This is due to the lower latent heat capacity of ethanol, which requires less energy to vaporize compared with water. Through the rotational viscometer test, ethanol performs better in lowering the viscosity of asphalt binders, which is essential in allowing produc- tion processes at low temperatures, as well as a better workability and aggregate coating. Ethanol can be expelled from the foamed asphalt binders at a higher rate due to its lower boiling point and latent heat.