The cost of noise reduction for departure and arrival operations of commercial tilt rotor aircraft

February 1976Includes bibliographical references (p. 50-51)The relationship between direct operating cost (DOC) and noise annoyance due to a departure and an arrival operation was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various noise goals at minimum DOC. These vehicles ranged across the spectrum of possible noise levels from completely unconstrained to the quietest vehicles that could be designed within the study ground rules. Optimization parameters were varied to find the minimum DOC. This basic variation was then extended to different aircraft sizes and technology time frames. It was concluded that reducing noise annoyance by designing for lower rotor tip speeds is a very promising avenue for future research and development. It appears that the cost of halving the annoyance compared to an unconstrained design is insignificant and the cost of halving the annoyance again is small.Prepared under contract for Ames Research Center, National Aeronautics and Space Administratio

Expenditure-based segmentation and visitor profiling at The Quays in Salford, UK

There is a substantial body of literature relating to tourism’s economic impact at the macro level, but less is known about tourist expenditure at a micro scale. This paper reports findings from a survey of day-visitor expenditure by category at The Quays in Salford, UK. Expenditure is influenced strongly by the visitor’s age, frequency of visitation and visit motivation. Heavy, medium and light expenditure segments and associated profiles are identified. ‘Heavy spenders’ are more likely to be female, in a family group and have shopping as the main motivation for the visit. The implications of the findings are discussed

A sodium fluoride sensitive mutant of Aspergillus nidulans

Fluoride is a widely spread naturally occurring substance in many foods and is used extensively for industrial purposes. The addition of fluoride to drinking water has been assumed to be safe. However, a number of studies have indicated that sodium fluoride is both genotoxic and cytotoxic to mammalian cells (Tsutsui et al. 1984 Mut. Res. 139:193-198). There is conflicting evidence suggesting that NaF is not genotoxic (Kram et al. 1978 Mut. Res. 57:51-55; Martin et al. 1979 Mut. Res. 66:159-167; Li et al. 1987 Mut. Res. 192:191-202) and can suppress the activity of polyfunctional alkylating agents (Obe and Slacik-Erben 1973 Mut. Res. 18:369-371)

Specialized Middle Level Teacher Preparation: Moving From Advocacy to Actualization

Is specialized middle level teacher preparation necessary? This essay offers the authors thoughts regarding middle level teaching and the necessity of specialized middle level teacher preparation. The reader is encouraged to further the discussion of middle level teacher preparation from advocacy to actualization

Narrative, identity, and recovery from serious mental illness: A life history of a runner

In recent years, researchers have investigated the psychological effects of exercise for people with mental health problems, often by focusing on how exercise may alleviate symptoms of mental illness. In this article I take a different tack to explore the ways in which exercise contributed a sense of meaning, purpose, and identity to the life of one individual named Ben, a runner diagnosed with schizophrenia. Drawing on life history data, I conducted an analysis of narrative to explore the narrative types that underlie Ben's stories of mental illness and exercise. For Ben, serious mental illness profoundly disrupted a pre-existing athletic identity removing agency, continuity, and coherence from his life story. By returning to exercise several years later, Ben reclaimed his athletic identity and reinstated some degree of narrative agency, continuity, and coherence. While the relationships between narrative, identity, and mental health are undoubtedly complex, Ben's story suggests that exercise can contribute to recovery by being a personally meaningful activity which reinforces identity and sense of self

Middle Level Teacher Preparation: Principals’ Perceptions of New Teacher Preparedness--RESEARCH

Drawing on the Framework for Effective Middle Level Teaching(Faulkner, Howell, &Cook, 2012; Howell, Cook, Faulkner, 2013), this interpretive, exploratory study utilized survey methodology to analyze 38 middle level principals’ perceptions of effective teaching practices and the preparedness of newly hired middle level teachers. The findings suggest there is difference in perceptions of new teacher preparedness between principals with middle level teacher certification and principals that were prepared to teach at other grade levels. While both groups acknowledged the need for better teacher preparation, principals with middle level teacher certification reported that newly hired teachers were less prepared for effective middle level teaching. The researchers identified two primary conclusions that impact the field of middle grades teacher preparation: (a) beginning middle grades teachers need to be better prepared for effective teaching and (b) principals perceive the preparation of new teachers differently depending upon their own teaching certification, with principals holding middle grades teaching certification being more critical of the level of preparation. While both strengths and weaknesses of preparation were identified in each of the six constructs, the most relevant and important conclusion is that middle level principals perceive beginning middle grades teachers as not being adequately prepared to address the demands of effective middle grades teaching in several constructs from the Framework for Effective Middle Level Teaching

Virtual-crystal approximation that works: Locating a composition phase boundary in Pb(Zr_{1-x}Ti_3)O_3

We present a new method for modeling disordered solid solutions, based on the virtual crystal approximation (VCA). The VCA is a tractable way of studying configurationally disordered systems; traditionally, the potentials which represent atoms of two or more elements are averaged into a composite atomic potential. We have overcome significant shortcomings of the standard VCA by developing a potential which yields averaged atomic properties. We perform the VCA on a ferroelectric oxide, determining the energy differences between the high-temperature rhombohedral, low-temperature rhombohedral and tetragonal phases of Pb(Zr_{1-x}Ti_x)O_3 at x=0.5 and comparing these results to superlattice calculations and experiment. We then use our new method to determine the preferred structural phase at x=0.4. We find that the low-temperature rhombohedral phase becomes the ground state at x=0.4, in agreement with experimental findings.Comment: 5 pages, no figure

A 610-MHz Galactic Plane Pulsar Search with the Giant Meterwave Radio Telescope

We report on the discovery of three new pulsars in the first blind survey of the north Galactic plane (45 < l < 135 ; |b| < 1) with the Giant Meterwave Radio telescope (GMRT) at an intermediate frequency of 610 MHz. The timing parameters, obtained in follow up observations with the Lovell Telescope at Jodrell Bank Observatory and the GMRT, are presented.Comment: 2 pages, 1 figure, to be published in conference proceedings of "40 years of pulsars ..", replaced figure

The holographic quantum effective potential at finite temperature and density

We develop a formalism that allows the computation of the quantum effective potential of a scalar order parameter in a class of holographic theories at finite temperature and charge density. The effective potential is a valuable tool for studying the ground state of the theory, symmetry breaking patterns and phase transitions. We derive general formulae for the effective potential and apply them to determine the phase transition temperature and density in the scaling region.Comment: 27 page

Banishing AdS ghosts with a UV cutoff

A recent attempt to make sense of scalars in AdS with "Neumann boundary conditions" outside of the usual BF-window $-(d/2)^2 < m^2 l^2 < -(d/2)^2 + 1$ led to pathologies including (depending on the precise context) either IR divergences or the appearance of ghosts. Here we argue that such ghosts may be banished by imposing a UV cutoff. It is also possible to achieve this goal in certain UV completions. An example is the above AdS theory with a radial cutoff supplemented by particular boundary conditions on the cutoff surface. In this case we explicitly identify a region of parameter space for which the theory is ghost free. At low energies, this theory may be interpreted as the standard dual CFT (defined with "Dirichlet" boundary conditions) interacting with an extra scalar via an irrelevant interaction. We also discuss the relationship to recent works on holographic fermi surfaces and quantum criticality.Comment: 20 pages, 9 figure