Solubility and freezing point depression (FPD) measurements of Na-1-ethanethiolate,Na-1-propanethiolate,Na-2-propanethiolate,Na-1-butanethiolate,and Na-2-methyl-2-propanethiolate salts in pure water

In this work, we have measured the solubility and the freezing point depression of Na-1-ethanethiolate, Na-1-propanethiolate, Na-2-propanethiolate, Na-1-butanethiolate, and Na-2-methyl-2-propanethiolate salts in pure water within the concentration range of 0–49 wt/wt% at 1?atm. The freezing point curves and solubility curves of five mercaptide salts have been measured at various concentrations of mercaptide salts and further used to find eutectic points.     

The effect of water on the thermal transitions of fish scales from Arapaima Gigas

Fish scales are collagen based structures that display interesting mechanical properties, particularly in the wet state. In this paper we study the effect of water content on the thermal transitions of scales from the Amazonian fish Arapaima Gigas by means of Differential Scanning Calorimeter (DSC) tests. The endothermic peaks found are discussed and the results are compared with previous studies of other collagen based structures. The peaks observed were found to depend on the water content of the samples. The role of water on the thermal stability of fish scales is discussed. The peak temperature related to the denaturation of collagen was found to increase with increasing water content. Hence, samples with higher water content were more thermally stable than samples with lower water content. This tendency is contradictory with regard to that observed on other collagen based structures such as bones and tendons.     

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.