Abstract: A concrete finishing apparatus and method for smoothing and flattening partially set-up concrete to a close-tolerance surface includes a movable unit that is movable and supported at a partially set-up concrete surface and at least one rotatable ring finishing member mounted to the movable unit. The rotatable ring finishing member is positioned at the concrete surface and rotatable to engage and finish the surface of the partially set-up concrete to a higher quality, closer-tolerance flat and level concrete floor surface. The apparatus may include a pair of rotatable ring finishing members that may be rotatable in opposite directions to enhance the floating and finishing processes and to transport any cement paste, sand, small aggregate, or concrete mix residue forward with the rotatable ring finishing members working surfaces to cut high areas and fill in any low areas as the concrete finishing apparatus moves over the partially set-up concrete.

Abstract: An apparatus and method of determining chemical dosage required to reduce sulfides in wastewater includes providing a headspace apart from the wastewater. The temperature of the wastewater and the concentration of sulfide gas in the headspace are measured. Dissolved hydrogen sulfide gas concentrations in the wastewater are calculated from the temperature of the wastewater and the concentration of sulfide gas in said headspace. When pH is monitored, dissolved sulfide concentrations can be calculated.

Abstract: A vehicle-based navigation system is described including a position locator that establishes the geographic position of the vehicle and a map database located external to and remote from the vehicle. The system determines at least one of a vehicle parameter and a personal parameter, and transfers data from the remote map database to the vehicle and displays the data in the vehicle at a resolution that is a function of at least one of a vehicle parameter and a personal parameter.

Abstract: A plug tray for growing, planting and transplanting plants includes a surface member having a plurality of rows of inner cells and a pair of rows of outer cells. Each row of outer cells is positioned proximate to an end of the surface member. A plurality of aeration apertures are formed in the surface member to thereby provide aeration to plants growing within the cells. The inner cells and outer cells are offset with respect to the major axis of the surface member to thereby provide increased strength and rigidity, allowing the tray to be manufactured using the relatively inexpensive process of thermoforming. The outer cells are configured such that the center-to-center distance between adjacent outer cells of a pair of plug trays placed end-to-end is substantially equal to the center-to-center distance between adjacent cells within a particular plug tray.