Analysis of a Stretched Derivative Aircraft with Open Rotor Propulsion

Research into advanced, high-speed civil turboprops received significant attention during the 1970s and 1980s when fuel efficiency was the driving focus of U.S. aeronautical research. But when fuel prices declined sharply there was no longer sufficient motivation to continue maturing the technology. Recent volatility in fuel prices and increasing concern for aviation's environmental impact, however, have renewed interest in unducted, open rotor propulsion and revived research by NASA and a number of engine manufacturers. Recently, NASA and General Electric have teamed to conduct several investigations into the performance and noise of an advanced, single-aisle transport with open rotor propulsion. The results of these initial studies indicate open rotor engines have the potential to provide significant reduction in fuel consumption compared to aircraft using turbofan engines with equivalent core technology. In addition, noise analysis of the concept indicates that an open rotor aircraft in the single-aisle transport class would be able to meet current noise regulations with margin. The behavior of derivative open rotor transports is of interest. Heavier, "stretched" derivative aircraft tend to be noisier than their lighter relatives. Of particular importance to the business case for the concept is how the noise margin changes relative to regulatory limits within a family of similar open rotor aircraft. The subject of this report is a performance and noise assessment of a notional, heavier, stretched derivative airplane equipped with throttle-push variants of NASA's initial open rotor engine design

Performance and Environmental Assessment of an Advanced Aircraft with Open Rotor Propulsion

Application of high speed, advanced turboprops, or "propfans," to transonic transport aircraft received significant attention during the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Unfortunately, after fuel prices declined sharply there was no longer sufficient motivation to continue maturing this technology. Recent volatility in fuel prices and increasing concern for aviation s environmental impact, however, have renewed interest in unducted, open rotor propulsion. Because of the renewed interest in open rotor propulsion, the lack of publicly available up-to-date studies assessing its benefits, and NASA s focus on reducing fuel consumption, a preliminary aircraft system level study on open rotor propulsion was initiated to inform decisions concerning research in this area. New analysis processes were established to assess the characteristics of open rotor aircraft. These processes were then used to assess the performance, noise, and emissions characteristics of an advanced, single-aisle aircraft using open rotor propulsion. The results of this initial study indicate open rotor engines have the potential to provide significant reductions in fuel consumption and landing-takeoff cycle NOX emissions. Noise analysis of the study configuration indicates that an open rotor aircraft in the single-aisle class would be able to meet current noise regulations with margin

Updated Assessment of an Open Rotor Airplane Using an Advanced Blade Design

Application of open rotor propulsion systems (historically referred to as "advanced turboprops" or "propfans") to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation's environmental impact have renewed interest in open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Over the last few years, NASA has revived and developed analysis capabilities to assess aircraft designs with open rotor propulsion systems. These efforts have been described in several previous papers along with initial results from applying these capabilities. The initial results indicated that open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicated that current noise regulations can be met with modern baseline blade designs. Improved blades incorporating low-noise features are expected to result in even lower noise levels. This paper describes improvements to the initial assessment, plus a follow-on study using a more advanced open rotor blade design to power the advanced singleaisle transport. The predicted performance and environmental results of these two advanced open rotor concepts are presented and compared

The logic of recurrent circuits in the primary visual cortex

Recurrent cortical activity sculpts visual perception by refining, amplifying or suppressing visual input. However, the rules that govern the influence of recurrent activity remain enigmatic. We used ensemble-specific two-photon optogenetics in the mouse visual cortex to isolate the impact of recurrent activity from external visual input. We found that the spatial arrangement and the visual feature preference of the stimulated ensemble and the neighboring neurons jointly determine the net effect of recurrent activity. Photoactivation of these ensembles drives suppression in all cells beyond 30 µm but uniformly drives activation in closer similarly tuned cells. In nonsimilarly tuned cells, compact, cotuned ensembles drive net suppression, while diffuse, cotuned ensembles drive activation. Computational modeling suggests that highly local recurrent excitatory connectivity and selective convergence onto inhibitory neurons explain these effects. Our findings reveal a straightforward logic in which space and feature preference of cortical ensembles determine their impact on local recurrent activity

Initial Assessment of Open Rotor Propulsion Applied to an Advanced Single-Aisle Aircraft

Application of high speed, advanced turboprops, or propfans, to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation s environmental impact have renewed interest in unducted, open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Unfortunately, in the two decades that have passed since open rotor concepts were thoroughly investigated, NASA has lost experience and expertise in this technology area. This paper describes initial efforts to re-establish NASA s capability to assess aircraft designs with open rotor propulsion. Specifically, methodologies for aircraft-level sizing, performance analysis, and system-level noise analysis are described. Propulsion modeling techniques have been described in a previous paper. Initial results from application of these methods to an advanced single-aisle aircraft using open rotor engines based on historical blade designs are presented. These results indicate open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicates that current noise regulations can be met with old blade designs and modern, noiseoptimized blade designs are expected to result in even lower noise levels. Although an initial capability has been established and initial results obtained, additional development work is necessary to make NASA s open rotor system analysis capability on par with existing turbofan analysis capabilities

Anti-oesophageal cancer activity in extracts of deep-water Marion Island sponges

Oesophageal cancer is one of the most common causes of cancer-related deaths in South African black males. The limited efficacy of chemotherapeutic agents to treat this disease has prompted a search for potential new chemical entities with anticancer properties. We report here on the evidence for anti-oesophageal cancer activity in the methanolic extracts of five species of sponges dredged from a depth of approximately 100 m in the vicinity of Marion Island in the Southern Ocean during the autumn of 2004

The Vehicle, 1967, Vol. 9 no. 1

Vol. 9, No. 1 Table of Contents Commentarypage 3 PoofMolly J. Evanspage 4 PreludeMike Baldwinpage 5 UntitledMike Baldwinpage 5 Where is Tomorrow?Paula Bresnanpage 6 Could It Be Or NotMary Hoeggerpage 7 PsalmAnthony Griggspage 7 Where Am I Going?William A. Framepage 8 Out of DarknessMarilyn Henry Hoodpage 9 She CriedMolly J. Evanspage 12 When I MoveAnthony Griggspage 13 Hi Ya, MorningWilliam A. Framepage 13 Summer Twilight ThoughtsSteve Allenpage 14 Too MuchBill Moserpage 16 Ink SketchWilliam A. Framepage 17 No. 1Molly J. Evanspage 18 Youth, So Hated and DamnedJeff Hendrickspage 18 GoneJackie Jaquespage 19 The JesterWilliam A. Framepage 20 ReflectionMike Baldwinpage 20 No. 3Molly J. Evanspage 21 EpitaphBill Moserpage 22 I Take A Long-Out-of-Use BookAnthony Griggspage 23https://thekeep.eiu.edu/vehicle/1016/thumbnail.jp

The Vehicle, 1967, Vol. 9 no. 1

Vol. 9, No. 1 Table of Contents Commentarypage 3 PoofMolly J. Evanspage 4 PreludeMike Baldwinpage 5 UntitledMike Baldwinpage 5 Where is Tomorrow?Paula Bresnanpage 6 Could It Be Or NotMary Hoeggerpage 7 PsalmAnthony Griggspage 7 Where Am I Going?William A. Framepage 8 Out of DarknessMarilyn Henry Hoodpage 9 She CriedMolly J. Evanspage 12 When I MoveAnthony Griggspage 13 Hi Ya, MorningWilliam A. Framepage 13 Summer Twilight ThoughtsSteve Allenpage 14 Too MuchBill Moserpage 16 Ink SketchWilliam A. Framepage 17 No. 1Molly J. Evanspage 18 Youth, So Hated and DamnedJeff Hendrickspage 18 GoneJackie Jaquespage 19 The JesterWilliam A. Framepage 20 ReflectionMike Baldwinpage 20 No. 3Molly J. Evanspage 21 EpitaphBill Moserpage 22 I Take A Long-Out-of-Use BookAnthony Griggspage 23https://thekeep.eiu.edu/vehicle/1016/thumbnail.jp

Ursinus College Alumni Journal, July 1960

President\u27s page • Dr. Paisley completes fifty years as President of the Board of Directors • Dr. McClure salutes Dr. Paisley • Senator Hugh Scott speaks at commencement • Horton preaches Baccalaureate sermon • Mrs. Omwake honored • 1960 Loyalty Fund • Dr. Boswell retires • Four professors given Bear Awards • Memorial minute • Faculty notes • A student reviews the past year at Ursinus • Alumni Day • Alumni elections • Thompson receives award • Admissions\u27 problems • Ursinus experiments in Swedish • Commencement Day • Colonel Campbell, \u2760 • The generous American • 1960 Loyalty Fund breaks all records • Lost alumni • The alumnus / alumna • A defense for the Alumni Association • Edward L. French, \u2738 • Paul E. Elicker, \u2714 • Warren K. Hess, \u2731 • Ursinus sends Morgan to NCAA track trials • Best track season in Ursinus history • Baseball review • Varsity Club news • Ursinus faces rebuilding job • Girls\u27 spring sports • Calling all grumblers • News about ourselves • Necrology • Weddings • Births • Ursinus captain\u27s chairhttps://digitalcommons.ursinus.edu/alumnijournal/1065/thumbnail.jp