Abstract: An elongate diffuser is disclosed comprising a diffuser body and a membrane attached to the diffuser body. The membrane is connected to the diffuser body so that introduction of gas at a working pressure into the diffuser displaces part of the membrane from contact with the diffuser body to provide an elongate sealed compartment between the membrane and a surface of the diffuser body. The compartment has a first lateral side interface region where the membrane contacts the diffuser body, a laterally intermediate region where the membrane is spaced apart from the diffuser body and a second lateral side interface region where the membrane contacts the diffuser body. The diffuser body surface which bounds the compartment comprises a recessed portion which is recessed away from the membrane between the first second lateral side interface regions.

Abstract: An elongate diffuser is disclosed comprising a diffuser body and a membrane attached to the diffuser body. The membrane is connected to the diffuser body so that introduction of gas at a working pressure into the diffuser displaces part of the membrane from contact with the diffuser body to provide an elongate sealed compartment between the membrane and a surface of the diffuser body. The compartment has a first lateral side interface region where the membrane contacts the diffuser body, a laterally intermediate region where the membrane is spaced apart from the diffuser body and a second lateral side interface region where the membrane contacts the diffuser body. The diffuser body surface which bounds the compartment comprises a recessed portion which is recessed away from the membrane between the first second lateral side interface regions.

Abstract: An elongate diffuser (10) comprises a diffuser body (30), and a membrane (20) attached so that introduction of gas at a working pressure into the diffuser displaces part of the membrane (20) from contact with the diffuser body (10) providing an elongate sealed compartment (50) between the membrane (20) and a surface (32) of the diffuser body (30). The gas can pass from the compartment (50) through the membrane (20) for aeration of fluid in which the diffuser (10) is immersed. The diffuser body surface (32) which bounds the compartment (50) is recessed away from the membrane (20) in use, to contribute to the lateral cross sectional area of the compartment (50) and facilitate distribution of gas along the diffuser by the compartment (50). An automatic purge valve for purging water from a gas feed pipe of a diffuser is also disclosed.

Abstract: An elongate diffuser (10) comprises a diffuser body (30), and a membrane (20) attached so that introduction of gas at a working pressure into the diffuser displaces part of the membrane (20) from contact with the diffuser body (10) providing an elongate sealed compartment (50) between the membrane (20) and a surface (32) of the diffuser body (30). The gas can pass from the compartment (50) through the membrane (20) for aeration of fluid in which the diffuser (10) is immersed. The diffuser body surface (32) which bounds the compartment (50) is recessed away from the membrane (20) in use, to contribute to the lateral cross sectional area of the compartment (50) and facilitate distribution of gas along the diffuser by the compartment (50). An automatic purge valve for purging water from a gas feed pipe of a diffuser is also disclosed.

Abstract: A method of generating a secure transaction log recording transaction data established between a first 10 and a second 20 data processing device. The transaction log includes transaction data derived from the first device that is digitally signed by the second device, and then digitally re-signed by the first device, with copies being stored locally to both devices. Any interference with the data by either device, or during transfer of data between them is evident to both devices. The transaction data may include data received and signed by an independent third party as a trusted third party.

Abstract: An electronic device has a touch sensitive surface (14) for entering text. The text is stored in memory (20) in a vector graphics format, preferably without carrying out character recognition.

Abstract: Telecommunication systems comprising terminals (1) and network-units (10) for exchanging messages via messaging servers (11) for client-to-client information are provided with detectors (7,14) for detecting control instructions and generators (6,15) for generating control instructions. The messages are provided with these control instructions for controlling interactions between terminals (1) and network-units (10). As a result, messaging servers (11) can now control different kinds of interactions in as well as across different kinds of networks. Said messages further comprise origin and destination identifications. Said control instructions comprise authentication instructions for authenticating said interaction, capability instructions or set up instruction for setting up a communication. Said messages can be in the form of XML messages. Bridging servers (30) bridge the gap between parties which can communicate with messaging servers (11) and parties which cannot.