Abstract: Control systems for recovery wheels, ventilation systems with recovery devices, buildings having ventilation, and methods of controlling recovery wheels and controlling or modifying ventilation systems. A parameter of ventilation systems or recovery devices, such as the speed of a recovery wheel, may be controlled as a function of pressure, differential pressure, flow rate, or fan speed, for example, to provide appropriate purge flow to maintain purge effectiveness and limit the carry-over of contaminants from a return/exhaust airstream to an outside/supply airstream, for instance, in a variable air-volume system. A purge angle may be set at a minimum position commensurate with a maximum flow rate and recovery-wheel speed may be reduced at lower flows to maintain purge effectiveness. In some embodiments, temperature and humidity are measured, and wheel speed is also controlled as a function of these measurements.

Abstract: Control systems for recovery wheels, ventilation systems with recovery devices, buildings having ventilation, and methods of controlling recovery wheels and controlling or modifying ventilation systems. A parameter of ventilation systems or recovery devices, such as the speed of a recovery wheel, may be controlled as a function of pressure, differential pressure, flow rate, or fan speed, for example, to provide appropriate purge flow to maintain purge effectiveness and limit the carry-over of contaminants from a return/exhaust airstream to an outside/supply airstream, for instance, in a variable air-volume system. A purge angle may be set at a minimum position commensurate with a maximum flow rate and recovery-wheel speed may be reduced at lower flows to maintain purge effectiveness. In some embodiments, temperature and humidity are measured, and wheel speed is also controlled as a function of these measurements.

Abstract: A personal surveillance system having a video camera and an audio microphone in a single package sufficiently small to be worn as a badge, lapel pin, or similarly small accessory. The audio/video package is coupled to a transmitter for transmitting an audio and video signal to a remote station. The remote station comprises a video cassette recorder responsive to a signal for recording that is generated on a continuous basis by the audio/video package in a signal band that is filtered before recording.

Abstract: A continuous dense phase conveying method and apparatus, for conveying large quantities of dry bulk material through a material conveying pipe, feed particulate material into the conveying pipe and supply a quantity of low pressure gas into the pipe to force particulate material to move therealong. A gas pressure within the conveying pipe is monitored. When this monitored pressure reaches a predetermined gas pressure level, a quantity of high pressure gas is supplied to the conveying pipe to force the particulate material to move continuously therealong.

Abstract: A suspendable folder is disclosed having a front panel and a back panel with their bottom edges and a segment of each of their lateral edges secured to one another. A segment of each pair of lateral edges secured to one another is defined by two points, the first of which is near the bottom edge of each panel. The second, upper point is spaced from the first point by a distance preferably selected from the range of approximately one half to two thirds the height of the back panel. At or near the second upper point, a circular radius cut is provided to assist in distributing tearing forces across a large area of both the front panel and back panel. At least one transverse score line is also provided above the radius cut in the front panel to permit easier opening and closing of the folder without tearing.

Abstract: A metal plunger tip for use in aluminum die casting operations includes a cylindrical body having an axially extending cavity therein and a shank of smaller diameter extending axially from the body for connection to a control rod. The plunger tip has at least one outwardly-facing safety indicator surface located at which a point intermediate the inside and outside diameters of the body, for the purpose of indicating the extent to which the outer surface of the body can be machined without reducing the wall thickness to an unsafe dimension.