A 20-hour VLBI observation with the NRAO VLBA and GBT in the NOAO Boötes field reaches an rms noise of 9 microJy per beam at 1.4 GHz. Three sources were detected at 10-milliarcsecond resolution within the GBT primary beam of FWHM 8.6, including the 20milliJy calibrator and two sub-milliJy sources. By tapering the visibility data, portions of the VLBA primary beam of FWHM 29 were imaged at poore...

Software often goes through a variety of extensions during its lifetime: adding new fields or new variants to a data structure, retroactively creating new type abstractions, and adding new operations on a data structure. As characterized by the extensibility problem, it should be possible to apply any combination of these types of extensions in any order. Mainstream object-oriented languages, h...

Example An operating system is a widely-used example of a complex concurrent system that manages many different types of applications and hardware. For instance, it coordinates and demultiplexes the communication between standard Internet networking applications, such as telnet, ftp, smtp, dns, and inetd, and hardware I/O devices, such as network interfaces, disk controllers, end-user terminals...

Direct injection compression ignition engines have proved to be the best option in heavy duty applications like transportation and power generation, but rapid depleting sources of conventional fossil fuels, their rising prices and ever increasing environmental issues are the major concerns. Alternate fuels, particularly biofuels are receiving increasing attention during the last few years. Biod...