Although solar air heaters in general have the same economic potential as solar water heaters, the state of the art remains a technical achievement awaiting commercial exploitation. This paper presents the use of porous construction to achieve efficient heat extraction from an energy absorbing...

For some time past, interest has been developing within the Aslib Research Department in the problems of establishing standard costs for information systems. A literature search recently conducted by the Department (R. Reynolds) has revealed a scarcity of usable information on this subject: such...

With a view to obtaining a set of standard times for information system operations, Aslib Research Department is developing and testing methods for collecting and analysing data on the time taken to perform certain operations. The current state of development of these methods is described. Data...