Managing a Farm in the Corn Borer Area

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Study of unconventional aircraft engines designed for low energy consumption

A study of unconventional engine cycle concepts, which may offer significantly lower energy consumption than conventional subsonic transport turbofans, is described herein. A number of unconventional engine concepts were identified and parametrically studied to determine their relative fuel-saving potential. Based on results from these studies, regenerative, geared, and variable-boost turbofans, and combinations thereof, were selected along with advanced turboprop cycles for further evaluation and refinement. Preliminary aerodynamic and mechanical designs of these unconventional engine configurations were conducted and mission performance was compared to a conventional, direct-drive turofan reference engine. Consideration is given to the unconventional concepts, and their state of readiness for application. Areas of needed technology advancement are identified

Study of Turbofan Engines Designed for Low Enery Consumption

Subsonic transport turbofan engine design and technology features which have promise of improving aircraft energy consumption are described. Task I addressed the selection and evaluation of features for the CF6 family of engines in current aircraft, and growth models of these aircraft. Task II involved cycle studies and the evaluation of technology features for advanced technology turbofans, consistent with initial service in 1985. Task III pursued the refined analysis of a specific design of an advanced technology turbofan engine selected as the result of Task II studies. In all of the above, the impact upon aircraft economics, as well as energy consumption, was evaluated. Task IV summarized recommendations for technology developments which would be necessary to achieve the improvements in energy consumption identified

Study, definition and analysis of pilot/system performance measurements for planetary entry experiments

Definition analysis for experimental prediction of pilot performance during planetary entr

Active clearance control system for a turbomachine

An axial compressor is provided with a cooling air manifold surrounding a portion of the shroud, and means for bleeding air from the compressor to the manifold for selectively flowing it in a modulating manner axially along the outer side of the stator/shroud to cool and shrink it during steady state operating conditions so as to obtain minimum shroud/rotor clearance conditions. Provision is also made to selectively divert the flow of cooling air from the manifold during transient periods of operation so as to alter the thermal growth or shrink rate of the stator/shroud and result in adequate clearance with the compressor rotor

Manual and automatic flight control during severe turbulence penetration

An analytical and experimental investigation of possible contributing factors in jet aircraft turbulence upsets was conducted. Major contributing factors identified included autopilot and display deficiencies, the large aircraft inertia and associated long response time, and excessive pilot workload. An integrated flight and thrust energy management director system was synthesized. The system was incorporated in a moving-base simulation and evaluated using highly experienced airline pilots. The evaluation included comparison of pilot workload and flight performance during severe turbulence penetration utilizing four control/display concepts: manual control with conventional full panel display, conventional autopilot (A/P-A) with conventional full panel display, improved autopilot (A/P-B) with conventional full panel display plus thrust director display, and longitudinal flight director with conventional full panel display plus thrust director display. Simulation results show improved performance, reduced pilot workload, and a pilot preference for the autopilot system controlling to the flight director command and manual control of thrust following the trim thrust director

Support for Instructional Leadership: Supervision, Mentoring, and Professional Development for U.S. School Leaders - Findings from the American School Leader Panel

With school leadership second only to teaching among school-related influences on student learning, principals can play an important role in school success. But how do their districts promote their effectiveness, especially in improving teaching? Based on a survey of the American School Leader Panel, a representative sample of principals from across the United States, this report explores the prevalence and quality of three important on-the-job supports for school leaders: supervision, mentorship and professional development (as defined by at least a day focused on principals). The good news is that two-thirds of principals report receiving some support. The bad news is that more than two thirds (68 percent) report that they don't receive all three sources of help. Mentoring, for example, is typically available only to first- or second-year principals or those encountering difficulties on the job, and only a minority of principals report that their districts require mentoring, even for first-year (49 percent of respondents) or struggling principals (21 percent). Also, the prevalence of support a principal receives may depend on the size of his or her school district. Both mentoring and professional development are more readily available in larger and medium-sized districts than smaller ones. The value principals place on the support they receive is linked to whether the support emphasizes the key aspect of principals' job—improving teachers' instruction. For example, all of the principals (100 percent) who reported that their mentors focused on instruction to a great extent also said that they prized the mentoring. That compares with a minority (40 percent) of principals who said their mentors devoted little to no time to instruction

Is All Campaigning Equally Positive? The Impact of District Level Campaigning on Voter Turnout at the 2010 British General Election

A significant comparative literature suggests that campaigning efforts by political parties impact positively, both in terms of mobilization and turnout. However, effects are not uniform. They may be affected by the electoral system used, the electoral circumstances and effectiveness of party management. Studies of district-level constituency campaigning in Britain have identified two important trends. First, that effective targeting is a core component of a successful district campaign strategy in terms of delivering electoral payoffs and that, over time, political parties have become better at targeting resources where they are needed most. While improvements in targeting have helped ensure that all three principal parties’ campaigns have tended to deliver electoral payoffs, a question has arisen as to whether increasingly ruthless partisan targeting by parties could have detrimental effects on overall levels of turnout. Second, they have shown how campaign techniques are continuously being modernised but that, despite these changes, just as in other democracies, more traditional labour-intensive campaigning tends to produce stronger electoral payoffs. This article therefore considers three questions in respect of the impact of district level campaigns on turnout: whether the combined campaign efforts of the three principal parties in Britain are associated with higher levels of turnout; whether the different campaigning styles of parties affect levels of turnout equally; and whether the campaigning efforts of different parties have differential effects on turnout and whether intense partisan targeting does indeed impact upon turnout overall. It shows that while campaigning boosts turnout, the impact varies by campaign technique and by party, as a function not only of targeting but also of electoral context

You get what you (don’t) pay for: The impact of volunteer labour and candidate spending at the 2010 British general election

The published version of this article is fully available from the publisher at the link below.Repeated evidence in Britain demonstrates the positive electoral payoffs from constituency campaigning. However, the impact of such campaigning varies depending upon the electoral context and the effectiveness of campaign management. Debate also exists in respect of the relative impact of traditional versus more modern campaign techniques, as well as between campaign techniques that incur cost and those that are carried out voluntarily. Such debates are of interest not only to academics and political parties, but also to regulators when considering whether to restrict campaign spending in the interests of electoral parity. This article uses candidate spending data and responses to an extensive survey of election agents at the British General Election of 2010 to assess the impact of both campaign expenditure and free, voluntary labour on electoral performance. It suggests that both have some independent impact, but that impact varies by party. The implications of these results are highly significant in both academic and regulatory terms—campaign expenditure can affect electoral outcomes but these effects are offset to some extent by voluntary efforts

Magnetic, Transport, and Thermal Properties of Single Crystals of the Layered Arsenide BaMn2As2

Growth of BaMn2As2 crystals using both MnAs and Sn fluxes is reported. Room temperature crystallography, anisotropic isothermal magnetization M versus field H and magnetic susceptibility chi versus temperature T, electrical resistivity in the ab plane rho(T), and heat capacity C(T) measurements on the crystals were carried out. The tetragonal ThCr2Si2-type structure of BaMn2As2 is confirmed. After correction for traces of ferromagnetic MnAs impurity phase using M(H) isotherms, the inferred intrinsic chi(T) data of the crystals are anisotropic with chi_{ab}/chi_{c} \approx 7.5 at T = 2 K. The temperature dependences of the anisotropic chi data suggest that BaMn2As2 is a collinear antiferromagnet at room temperature with the easy axis along the c axis, and with an extrapolated Neel temperature T_N \sim 500 K. The rho(T) decreases with decreasing T below 310 K but then increases below \sim 50 K, suggesting that BaMn2As2 is a small band-gap semiconductor with an activation energy of order 0.03 eV. The C(T) data from 2 to 5 K are consistent with this insulating ground state, exhibiting a low temperature Sommerfeld coefficient gamma = 0.0(4) mJ/mol K^2. The Debye temperature is determined from these data to be theta_D = 246(4) K. BaMn2As2 is a potential parent compound for ThCr2Si2-type superconductors.Comment: 7 pages, 6 figures; v2: typos corrected, additional data and discussion, accepted for publication in Phys. Rev.