Implementing spring-foam technology to design a lightweight and comfortable aircraft seat-pan.

This paper investigates whether spring-foam technology in an aircraft seat-pan can reduce weight and at the same time provide equal or better comfort. Firstly, through literature studies and using an iterative design process a prototype seat-pan was designed and developed using spring-foam technology. The (dis)comfort of this seat was compared with a standard aircraft seat-pan. Twenty two participants were asked to sit in each seat for 90 min, completing a questionnaire every 15 min. At the end of each seating session pressure map recordings were made of the seat-pans. The results showed that the prototype seat-pan has on average a significantly higher comfort for the first 30 min and at a 60 min recording than the standard seat-pan. The discomfort and long term comfort were not significantly influenced. The pressure distribution on the prototype seat-pan was significantly closer to an ideal pressure distribution than a conventional seat-pan. In addition, the prototype seat-pan had a significantly larger contact area and lower average pressure. The seat-cushion weighs 20% less than the conventional seat-cushion. The study indicates that a seat-pan design using spring-foam technology can be lighter and more comfortable than conventional foam cushion materials. It is recommended to optimize the prototype seat further and conduct long term (dis)comfort studies with a broader variation in subjects' age.

Half-Century Ammonia Emissions From Agricultural Systems in Southern Asia: Magnitude, Spatiotemporal Patterns, and Implications for Human Health.

Much concern has been raised about the increasing threat to air quality and human health due to ammonia (NH3) emissions from agricultural systems, which is associated with the enrichment of reactive nitrogen (N) in southern Asia (SA), home of more than 60% the world's population (i.e., the people of West, central, East, South, and Southeast Asia). Southern Asia consumed more than half of the global synthetic N fertilizer and was the dominant region for livestock waste production since 2004. Excessive N application could lead to a rapid increase of NH3 in the atmosphere, resulting in severe air and water pollution in this region. However, there is still a lack of accurate estimates of NH3 emissions from agricultural systems. In this study, we simulated the agricultural NH3 fluxes in SA by coupling the Bidirectional NH3 exchange module (Bi-NH3) from the Community Multi-scale Air Quality model with the Dynamic Land Ecosystem Model. Our results indicated that NH3 emissions were 21.3 ± 3.9 Tg N yr-1 from SA agricultural systems with a rapidly increasing rate of ~0.3 Tg N yr-2 during 1961-2014. Among the emission sources, 10.8 Tg N yr-1 was released from synthetic N fertilizer use, and 10.4 ± 3.9 Tg N yr-1 was released from manure production in 2014. Ammonia emissions from China and India together accounted for 64% of the total amount in SA during 2000-2014. Our results imply that the increased NH3 emissions associated with high N inputs to croplands would likely be a significant threat to the environment and human health unless mitigation efforts are applied to reduce these emissions.