Abstract: The present invention is an indirect evaporative cooling module preferably made from extruded, twin-walled, corrugated, fluted plastic sheeting. Sheets of this corrugated material are cut into plates which are preferably laminated together to form the primary and secondary passages that comprise the heat exchanger core. These passages can be configured any number of ways, from vertical to horizontal to diagonal, and flow through these passages can be cross-flow, counter-flow and even baffle-flow. Increased heat exchange efficiency is achieved through a variety of ways, for example, by including an efficient water distribution means at the top of the heat exchanger, evaporative mesh extending through and below the heat exchanger for water distribution and pre-cooling, the creation of top and bottom heat exchange chambers by channeling water directly to the bottom zone of the heat exchanges passages, and roughening the surface of the sheets to increase heat transfer and to increase surface area.

Abstract: A teaching device to teach children time telling skills. The device comprises of a base, a rotatable peripheral ring with selector window, a top surface that represents the face of a clock, and a minute hand whose point is linked to the rotatable peripheral ring at the selector window and hour hand that individually rotate about a common pivot. The device uses a color and script coding ring and a separate color matching system for two distinct time telling functions as follows: (1) the minute color and script coding method enables the child to manipulate the minute and hour hands to match colors and script that will establish a realistic minute-hour hand relationship for any given time, and (2) the hour color matching system enables the child to decide whether minutes shown in the selector window are after the previous hour or before the succeeding hour. In addition the coding allows the child to choose the actual hour in question.