Object-oriented optimal controller for a batch dryer system

We describe the synthesis of an optimal control law and its implementation using object-oriented programming in the Java language. Our aim is to optimize the performance of a batch dryer system, which presents several problems such as time delay in the input and overshoot. The experimental results indicate that the control law effectively reduces the energy applied to the actuators in order to reach and maintain the desired temperature of the process. As for the implementation in the Java language, it allows to use the control law regardless of the operating system while providing robustness and stability.     

Conversion of waste tires to liquid products via sodium carbonate catalytic pyrolysis

This study deals with the pyrolysis of waste tires supplied from the transport industry. The base material of tire is latex, which is derived from natural rubber trees. Nowadays rubber (Hevea brasiliensis) is a fast-growing tropical tree crop, which is being cultivated for latex and ultimately for tire production. Waste tires can be recycled for energy and valuable materials in many ways; however tire burning is the most common practice for heat generation. In recent years, the catalytic conversion of waste tires through pyrolysis into liquid, solid, and gas products was investigated. Liquids product was produced from the catalytic pyrolysis of waste tire at high temperature (up to 600°C) using sodium carbonate (Na₂CO₃) as a catalyst. Thermo-physical characteristics of the produced liquid samples showed that up to 85% of the produced oil can be used in internal combustion engines. Gasoline and diesel fuel contents in the liquid products are 45% and 40%, respectively. The gas chromatographic (GC) analysis of the volatile fraction of pyrolysis products showed styrene (28.1%) and butadiene (10.7%) as dominant compounds. The gaseous phase includes C₁–C₄ hydrocarbons (4.8%) and the liquid phase includes C₅–C₈ hydrocarbons (6.5%) of the total products.     

Integrating “standard” residents into “non-standard” communities: a longitudinal analysis of social capital in a new urbanist development

This article examines how levels of social capital in a new urbanist community change over time. We collected demographic and social capital data in a new urbanist community in 2001 and then again in 2010. The findings indicate that this community experienced an overall decline in social capital over this nine-year period. Additionally, we found that while residents new to the community were less concerned with social capital than long-term residents in the community, the latter group had also declined significantly in their levels of social capital. Overall, the results suggest that planners of new urbanist and other intentional communities should consider the impact of changing demographics when designing new subdivisions. Most importantly, residents and community leaders need to consider alternative means by which social capital can be retained as new residents are integrated into established communities.     

Optimized Discrete Control Law for Quadrotor Stabilization: Experimental Results

This paper deals with the real-time stabilization of a Quadrotor mini helicopter applying a discrete optimal control. A discrete control strategy is better adapted to be executed in a micro-controller, therefore better results are expected with respect to continuous case. Furthermore, the optimal control law allows to helicopter to save energy and then increase its time of flight. The discrete optimal control law is synthesized considering an infinite horizon together with an exact linearization of the nonlinear dynamics of flying vehicle. At the end of this procedure the optimal control law obtained through an exact linearization is simple and easier to tune compared to the optimal strategy where the exact linearization is not performed. Taking into account the obtained experimental results, the proposed control technique produces an appropriate stabilization of the mini UAV.