311 research outputs found

    Effect of control logic modifications on airstart performance of F100 engine model derivative engines in an F-15 airplane

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    A series of airstarts were conducted in an F-15 airplane with two prototype Pratt and Whitney F100 Engine Model Derivative engines equipped with Digital Electronic Engine Control (DEEC) systems. The airstart envelope and the time required for airstarts were defined. Comparisons were made between the original airstart logic, and modified logic which was designed to improve the airstart capability. Spooldown airstarts with the modified logic were more successful at lower altitudes than were those with the original logic. Spooldown airstart times ranged from 33 seconds at 250 knots to 83 seconds at 175 knots. The modified logic improved the airstart time from 31% to 53%, with the most improved times at slower airspeeds. Jet fuel starter (JFS)-assisted airstarts were conducted at 7000 m and airstart times were significantly faster than unassisted airstarts. The effect of altitude on airstart times was small

    Analyzing Medication Documentation in Electronic Health Records: Dental Students’ Self-Reported Behaviors and Charting Practices

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    The aim of this two-part study was to assess third- and fourth-year dental students’ perceptions, self-reported behaviors, and actual charting practices regarding medication documentation in axiUm, the electronic health record (EHR) system. In part one of the study, in fall 2015, all 125 third- and 85 fourth-year dental students at one U.S. dental school were invited to complete a ten-item anonymous survey on medication history-taking. In part two of the study, the EHRs of 519 recent dental school patients were randomly chosen via axiUm query based on age >21 years and the presence of at least one documented medication. Documentation completeness was assessed per EHR and each medication based on proper medication name, classification, dose/frequency, indication, potential oral effects, and correct medication spelling. Consistency was evaluated by identifying the presence/absence of a medical reason for each medication. The survey response rate was 90.6% (N=187). In total, 64.5% of responding students reported that taking a complete medication history is important and useful in enhancing pharmacology knowledge; 90.4% perceived it helped improve their understanding of patients’ medical conditions. The fourth-year students were more likely than the third-year students to value the latter (p=0.0236). Overall, 48.6% reported reviewing patient medications with clinic faculty 76-100% of the time. The respondents’ most frequently cited perceived barriers to medication documentation were patients’ not knowing their medications (68.5%) and, to a much lesser degree, axiUm limitations (14%). Proper medication name was most often recorded (93.6%), and potential oral effects were recorded the least (3.0%). Medication/medical condition consistency was 70.6%. In this study, most of the students perceived patient medication documentation as important; however, many did not appreciate the importance of all elements of a complete medication history, and complete medication documentation was low

    Summary of results of NASA F-15 flight research program

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    NASA conducted a multidisciplinary flight research program on the F-15 airplane. The program began in 1976 when two preproduction airplanes were obtained from the U.S. Air Force. Major projects involved stability and control, handling qualities, propulsion, aerodynamics, propulsion controls, and integrated propulsion-flight controls. Several government agencies and aerospace contractors were involved. In excess of 330 flights were flown, and over 85 papers and reports were published. This document describes the overall program, the projects, and the key results. The F-15 was demonstrated to be an excellent flight research vehicle, producing high-quality results

    Augmentor transient capability of an F100 engine equipped with a digital electronic engine control

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    An F100 augmented turbofan engine equipped with digital electronic engine control (DEEC) system was evaluated. The engine was equipped with a specially modified augmentor to provide improved steady state and transient augmentor capability. The combination of the DEEC and the modified augmentor was evaluated in sea level and altitude facility tests and then in four different flight phases in an F-15 aircraft. The augmentor configuration, logic, and test results are presented

    A preliminary investigation of the use of throttles for emergency flight control

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    A preliminary investigation was conducted regarding the use of throttles for emergency flight control of a multiengine aircraft. Several airplanes including a light twin-engine piston-powered airplane, jet transports, and a high performance fighter were studied during flight and piloted simulations. Simulation studies used the B-720, B-727, MD-11, and F-15 aircraft. Flight studies used the Lear 24, Piper PA-30, and F-15 airplanes. Based on simulator and flight results, all the airplanes exhibited some control capability with throttles. With piloted simulators, landings using manual throttles-only control were extremely difficult. An augmented control system was developed that converts conventional pilot stick inputs into appropriate throttle commands. With the augmented system, the B-720 and F-15 simulations were evaluated and could be landed successfully. Flight and simulation data were compared for the F-15 airplane

    Bringing the Ivory Tower and Real World Together: Lessons Learned in the Collaborative Process of Preparing Effective Teachers

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    When the “ivory tower” world of educator preparation faculty collides with the “real world” of in-service teachers, the result can be a partnership that is committed to preparing teachers equipped to meet the needs of diverse learners in 21st century classrooms. The lessons learned in the development of such a partnership include a focus on: a) authentic engagement of all stakeholders; b) honest, diplomatic, and timely communication; c) support and scaffolding for pre-service teachers; d) a variety of authentic assessment measures; and e) assistance for new teachers during the induction period. Strengthening the bonds between university faculty and classroom teachers has contributed to the success of pre-service and beginning teachers and to the enhancement of P-12 student learning

    Flight Research Using F100 Engine P680063 in the NASA F-15 Airplane

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    The value of flight research in developing and evaluating gas turbine engines is high. NASA Dryden Flight Research Center has been conducting flight research on propulsion systems for many years. The F100 engine has been tested in the NASA F-15 research airplane in the last three decades. One engine in particular, S/N P680063, has been used for the entire program and has been flown in many pioneering propulsion flight research activities. Included are detailed flight-to-ground facility tests; tests of the first production digital engine control system, the first active stall margin control system, the first performance-seeking control system; and the first use of computer-controlled engine thrust for emergency flight control. The flight research has been supplemented with altitude facility tests at key times. This paper presents a review of the tests of engine P680063, the F-15 airplanes in which it flew, and the role of the flight test in maturing propulsion technology

    Flight and Static Exhaust Flow Properties of an F110-GE-129 Engine in an F-16XL Airplane During Acoustic Tests

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    The exhaust flow properties (mass flow, pressure, temperature, velocity, and Mach number) of the F110-GE-129 engine in an F-16XL airplane were determined from a series of flight tests flown at NASA Dryden Flight Research Center, Edwards, California. These tests were performed in conjunction with NASA Langley Research Center, Hampton, Virginia (LARC) as part of a study to investigate the acoustic characteristics of jet engines operating at high nozzle pressure conditions. The range of interest for both objectives was from Mach 0.3 to Mach 0.9. NASA Dryden flew the airplane and acquired and analyzed the engine data to determine the exhaust characteristics. NASA Langley collected the flyover acoustic measurements and correlated these results with their current predictive codes. This paper describes the airplane, tests, and methods used to determine the exhaust flow properties and presents the exhaust flow properties. No acoustics results are presented

    Astrophysical Reaction Rates for 10^{10}B(p,α\alpha)7^{7}Be and 11^{11}B(p,α\alpha)8^{8}Be From a Direct Model

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    The reactions 10^{10}B(p,α\alpha)7^{7}Be and 11^{11}B(p,α\alpha)8^{8}Be are studied at thermonuclear energies using DWBA calculations. For both reactions, transitions to the ground states and first excited states are investigated. In the case of 10^{10}B(p,α\alpha)7^{7}Be, a resonance at ERes=10E_{Res}=10 keV can be consistently described in the potential model, thereby allowing the extension of the astrophysical SS-factor data to very low energies. Strong interference with a resonance at about ERes=550E_{Res}=550 keV require a Breit-Wigner description of that resonance and the introduction of an interference term for the reaction 10^{10}B(p,α1\alpha_1)7^{7}Be∗^*. Two isospin T=1T=1 resonances (at ERes1=149E_{Res1}=149 keV and ERes2=619E_{Res2}=619 keV) observed in the 11^{11}B+p reactions necessitate Breit-Wigner resonance and interference terms to fit the data of the 11^{11}B(p,α\alpha)8^{8}Be reaction. SS-factors and thermonuclear reaction rates are given for each reaction. The present calculation is the first consistent parametrization for the transition to the ground states and first excited states at low energies.Comment: 27 pages, 5 Postscript figures, uses RevTex and aps.sty; preprint also available at http://quasar.physik.unibas.ch/ Phys. Rev. C, in pres

    Impact of Paired Central and Peripheral Blood Cultures in Children With Cancer

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    Children with cancer require central venous access which carries risk for line-related infections. The necessity of peripheral and central blood cultures is debated for those with fevers. We evaluated and described results for first episode of paired blood cultures from children with cancer who have a central venous line using retrospective database. Blood culture results, laboratory data, and medical outcomes were included. Descriptive analyses of blood culture results and clinical data were performed. There were 190 episodes of paired positive blood cultures with 167 true positive episodes. Of the true positive episodes, 104 (62.3%) were positive in both central and peripheral cultures, 42 (25.1%) were positive in central only cultures, and 21 (12.6%) were positive in peripheral cultures only. Intensive care unit admission within 48 hours after blood cultures (n=33) differed significantly: 28.7% for both central and peripheral, 10% for central only, and 0% for peripheral only (P=0.009). Central line removal (n=34) differed by type of positivity but was not significant: 22.1% for both central and peripheral, 23.8% for central only, and 4.8% for peripheral only (P=0.15). Peripheral blood cultures provided important medical information yet had differences in short-term clinical outcomes. Further evaluation of medical decision making is warranted
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