Abstract: A method for studying and evaluating the extent and type of air pollution by evaluating samples collected from the earth's atmosphere including the steps of providing cyclic, computer controlled, condensation on a chilled surface where the collection form is either frost or solid depending upon collection conditions and the frost or solid is subsequently converted to liquid form for evaluation and testing.

Abstract: A method of transmitting half-sinewave ultrasonic monopulses utilizes a flip-flop (22) to reverse the states of a bridge circuit (Q.sub.1 -Q.sub.4) with each output pulse from a timing pulse generator (20). This reverses the polarity of a dc voltage which stresses a piezoelectric transducer (24) to substantially its limit. Each pulse from the timing generator thus causes one mechanical transition of the transducer and clamps it in its reversed stress condition, thereby producing a half-sinewave ultrasonic output for each timing pulse.

Abstract: A method and apparatus for locating and mapping a pool of a pollutant (12) in a body of water (11) comprising the steps of scanning the bottom of said body of water with ultrasonic energy using a transducer (10) periodically pulsed to project pulse envelopes of acoustic energy downwardly to the bottom (14) of the body of water and receiving echo returns from the bottom preceded by echo returns from a reflective interface (13) with a pool of pollutant, if present. The presence of an echo return from an interface (13) as a precursor to an echo return from the bottom indicates the presence of the pool of pollutant at the navigational position of the transducer as the process of scanning continues. Locating and marking the perimeter of the pool permits rapid clean up operations to be directed.

Abstract: A hinged window assembly for vehicles adapted to be installed substantially entirely from the vehicle exterior. The assembly includes a window pane and at least one hinge preferably bonded with a suitable adhesive directly to the window pane surface without any hinge securing structure extending into or through the window. In a preferred form, the hinge is formed from flexible, resilient metal and cooperates with a sealing weather strip forming a seal between the preferred glass window pane and a vehicle body. Preferably, the fastening structure for attaching the hinge to a vehicle body is concealed from view behind the assembly when viewed from the vehicle exterior.

Abstract: A lightweight, economical window assembly for vehicles which is assembled to a vehicle as a unit preferably from the exterior, while providing strength, decorative trim, as well as a sealing function. The assembly includes a window pane, one of several types of decorative frame or trim members surrounding the pane, and one or more attaching members secured directly to the pane but concealed from view from the exterior of the assembly. Preferably the pane is glass and the attaching members are metallic studs rigidly and securely bonded directly to the glass surface with a suitable adhesive system such as that marketed under the Tenabond trademark.

Abstract: A photomicrographic system for measuring the number, size distribution and movement rate of foreign matter, e.g.