Water in 70 percent of the cities in the United States is hard enough that softening is either required or recommended. It is estimated that approximately 30 percent of all homes in the United States use water softeners. Water softeners, the cation exchange types suited for residential use, exchange sodium...
More than 30,000 potential Superfund sites have been identified. Heavy metals are contaminants at many of these Superfund sites. The average cost of cleanup a single-typical Superfund site currently stands at $20 million, and it is expected that the cost may escalate to $50 million within the next decade. Problems...
The bacterium most frequently used in microbial
leaching processes and studies is Thiobacillus
ferrooxidans. Applications of this bacterium include the
treatment of coal, low-grade ores and industrial solid
wastes for the solubilization of pyrite and other trace
metals associated with sulfides. The goal of this study
was the development of...
A Mobile Ad-hoc NETwork (MANET) is collection of wireless mobile nodes without a network infrastructure or centralized administration. Although MANETs can be used in many applications, such as mobile Internet, military communication, and disaster relief networks, a number of challenges remain. These include routing, medium access control, security, scalability, energy...
The fungi that cause mold and stain of freshly sawn lumber result in millions of dollars in losses to the forest products industry. Stain and mold are typically prevented by either kiln drying or by application of a topical fungicide. While these treatments are effective, kiln drying is costly and...
Supercritical fluid (SCF) impregnation is a promising preservative treatment method, however, the development of SCF processes has been slowed by a limited understanding of the process. Developing a better understanding of the effects of various process parameters on treatment results would allow for a more rational development of SCF impregnation....
This multiple case study explores issues of equity in science education through an examination of how teachers' reasoning patterns compare with students' reasoning patterns during inquiry-based lessons. It also examines the ways in which teachers utilize students' cultural and linguistic resources, or funds of knowledge, during inquiry-based lessons and the...
The sliding mode controller, based on the theory
of the Variable Structure System (VSS), is considered
for a robot manipulator. By consideration of VSS theory,
the nonlinear interactions of manipulator dynamics
are suppressed by use of linear sliding equations, and
VSS robustness with respect to the unknown physical manipulator
parameter...