Abstract: A coaxial ventilator (20) exchanges atmosphere between parts of a building (22) that are at differing heights. The coaxial ventilator (20) includes an outer conduit (24) that extends from an upper end (42) thereof downward to a lower end (44) thereof. The outer conduit (24) surrounds an inner conduit (62) that extends substantially the entire length of the outer conduit (24). Both the outer and inner conduits (24, 62) are open at their respective upper ends (42, 66) and lower ends (44, 68). Temperatures of atmosphere both surrounding and within the outer conduit (24) and the inner conduit (62) induce an exchange of atmosphere between the coaxial ventilator (20) and surrounding atmosphere.

Abstract: A system for offer based restaurant reservations comprises a processor and a memory. The processor is configured to: receive a request for a reservation including a set of attributes such as a date or date range, a time range, a location, a cuisine, and a party size; determine a set of available reservations based on an actual table availability for the date, time, and the party size; determine one or more offers based on the date, time, and the party size; determine an overlapping subset between the set of available reservations and the one or more offers; and provide an indication of the overlapping subset. The memory is coupled to the processor and is configured to provide the processor with instructions.