Abstract: A solar tile assembly (1A) comprises a removable rectangular outer panel (1) that comprises ten photovoltaic cells (3) disposed on the outermost surface thereof, and a substantially rectangular inner support structure (2). Thc photovoltaic cells (3) cover the lower portion of the outer panel (1). Any suitable photovoltaic means may be used for the solar tile assembly. The outer panel (1) is secured to the inner support structure (2) using two fasteners (5a, 5b) disposed at the front end of the solar tile assembly (1A). The fasteners (5a, 5b) may typically be quarter or half turn captive fasteners. These types of fasteners have the added advantage of being retained by the outer panel (1) during assembly/disassembly processes. The inner support structure (2) comprises a framework at one end of which there is formed a lower stepped interlockable section (4). In use the interlockable section (4) is disposed under a portion of an adjacent tile assembly, as is well known in the art of roof tile design.

Abstract: Triboelectricity, that is the electrostatic charging of materials by rubbing them against one another, is used to identify particular plastics materials which produce a characteristic charge polarity when rubbed against another known material. An apparatus (24) for carrying out this identification mounts different reference materials (30, 32, 34) so that they can be rubbed against the material (44) to be identified to create electrostatic charges which are then processed by a logic circuit to identify the nature of the sample.

Abstract: A sealed connector which can be used for making electrical connection underwater. The connector comprises two chambers one behind the other, the inner chamber containing an electrical connection terminal and being closed by a first diaphragm penetrable by a plug contact, the outer chamber being closed by a second diaphragm also penetrable by the plug contact, both chambers being filled with an electrically insulating grease, jelly or similarly viscous liquid.