Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems

Modelling electronic service systems using UML

This paper presents a profile for modelling systems of electronic services using UML. Electronic services encapsulate business services, an organisational unit focused on delivering benefit to a consumer, to enhance communication, coordination and information management. Our profile is based on a formal, workflow-oriented description of electronic services that is abstracted from particular implementation technologies. Resulting models provide the basis for a formal analysis to verify behavioural properties of services. The models can also relate services to management components, including workflow managers and Electronic Service Management Systems (ESMSs), a novel concept drawn from experience of HP Service Composer and DySCo (Dynamic Service Composer), providing the starting point for integration and implementation tasks. Their UML basis and platform-independent nature is consistent with a Model-Driven Architecture (MDA) development strategy, appropriate to the challenge of developing electronic service systems using heterogeneous technology, and incorporating legacy systems

Social Relationships Among Captive Tufted Titmice (\u3cem\u3eParus bicolor\u3c/em\u3e linnaeus) and Carolina Chickadees (\u3cem\u3eParus carolinensis\u3c/em\u3e audubon)

Some time ago as a result of study in ornithology and perusal of literature in the University of Tennessee libraries, I became interested in observing behavior of birds closely, i.e., particularly captive birds. In the literature I found no mention of the use of feeding behavior as a focal point for observations concerning species interaction and dominance relationships. Therefore, after consultation with Professor Howell, approval of plans, and receipt of funds from the University of Tennessee, I built and aviary. We decided to build the aviary of the roof of the east wing of Hesler Biology Building, University of Tennessee campus because of the secluded nature of the site. It was an outdoor site easily and conveniently reached by myself and Professor Howell and was not subject to visits by unauthorized personnel

Flight tests of a clear-air turbulence alerting system

The detection of clear-air turbulence (CAT) ahead of an aircraft in real-time by an infrared (IR) radiometer is discussed. It is noted that the alter time and reliability depend on the band-pass of the IR filter used and on the altitude of the aircraft. Results of flights tests indicate that a bandpass of 20 to 40 microns appears optimal for altering the aircraft crew to CAT at times before encounter of 2 to 9 min. Alert time increases with altitude, as the atmospheric absorption determining the horizontal weighting is reduced

Mexico, SOURCES OF STATE PRACTICE IN INTERNATIONAL LAW

Estados Unidos Mexicanos is the successor State of Spain in the Northern region of the former Spanish empire in the Americas. Pope Alexander VI issued a papal bull on May 4, 1493, fixing the line of demarcation of conquered territories between the Kings of Spain and Portugal thereby avoiding future conflict; this papal bull in effect granted the then-unexplored territory of what is now Mexico to the Spanish crown. Heman de Cortes conquered the Aztec empire in 1521 and Spain ruled the territory until Mexican independence in the early 19th century. The territory was called Nueva Espana (New Spain) and its political capital was in what is today Mexico City

Two New Particles

Caltech researchers re-discover two new elementary particles of matter--but, far from simplifying our understanding of nature, the discovery makes it even more difficult

Energy efficient engine: Flight propulsion system, preliminary analysis and design update

The preliminary design of General Electric's Energy Efficient Engine (E3) was reported in detail in 1980. Since then, the design has been refined and the components have been rig-tested. The changes which have occurred in the engine and a reassessment of the economic payoff are presented in this report. All goals for efficiency, environmental considerations, and economic payoff are being met. The E3 Flight Propulsion System has 14.9% lower sfc than a CF6-50C. It provides a 7.1% reduction in direct operating cost for a short haul domestic transport and 14.5% reduction for an international long distance transport