Flight-measured buffet characteristics of a supercritical wing and a conventional wing on a variable-sweep airplane

Windup-turn maneuvers were performed to assess the buffet characteristics of the F-111A aircraft and the same aircraft with a supercritical wing, which is referred to as the F-111 transonic aircraft technology (TACT) aircraft. Data were gathered at wing sweep angles of 26, 35, and 58 deg for Mach numbers from 0.60 to 0.95. Wingtip accelerometer data were the primary source of buffet information. The analysis was supported by wing strain-gage and pressure data taken in flight, and by oil-flow photographs taken during tests of a wind tunnel model. In the transonic speed range, the overall buffet characteristics of the aircraft having a supercritical wing are significantly improved over those of the aircraft having a conventional wing

Epistemic Closure in Folk Epistemology

We report the results of four empirical studies designed to investigate the extent to which an epistemic closure principle for knowledge is reflected in folk epistemology. Previous work by Turri (2015a) suggested that our shared epistemic practices may only include a source-relative closure principle—one that applies to perceptual beliefs but not to inferential beliefs. We argue that the results of our studies provide reason for thinking that individuals are making a performance error when their knowledge attributions and denials conflict with the closure principle. When we used research materials that overcome what we think are difficulties with Turri’s original materials, we found that participants did not reject closure. Furthermore, when we presented Turri’s original materials to non-philosophers with expertise in deductive reasoning (viz., professional mathematicians), they endorsed closure for both perceptual and inferential beliefs. Our results suggest that an unrestricted closure principle—one that applies to all beliefs, regardless of their source—provides a better model of folk patterns of knowledge attribution than a source-relative closure principle

A Density Independent Formulation of Smoothed Particle Hydrodynamics

The standard formulation of the smoothed particle hydrodynamics (SPH) assumes that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives of other quantities. However, this assumption breaks down at the contact discontinuity. At the contact discontinuity, the density of the low-density side is overestimated while that of the high-density side is underestimated. As a result, the pressure of the low (high) density side is over (under) estimated. Thus, unphysical repulsive force appears at the contact discontinuity, resulting in the effective surface tension. This tension suppresses fluid instabilities. In this paper, we present a new formulation of SPH, which does not require the differentiability of density. Instead of the mass density, we adopt the internal energy density (pressure), and its arbitrary function, which are smoothed quantities at the contact discontinuity, as the volume element used for the kernel integration. We call this new formulation density independent SPH (DISPH). It handles the contact discontinuity without numerical problems. The results of standard tests such as the shock tube, Kelvin-Helmholtz and Rayleigh-Taylor instabilities, point like explosion, and blob tests are all very favorable to DISPH. We conclude that DISPH solved most of known difficulties of the standard SPH, without introducing additional numerical diffusion or breaking the exact force symmetry or energy conservation. Our new SPH includes the formulation proposed by Ritchie & Thomas (2001) as a special case. Our formulation can be extended to handle a non-ideal gas easily.Comment: 24 pages, 21 figures. Movies and high resolution figures are available at http://v1.jmlab.jp/~saitoh/sph/index.htm

The thermodynamics of collapsing molecular cloud cores using smoothed particle hydrodynamics with radiative transfer

We present the results of a series of calculations studying the collapse of molecular cloud cores performed using a three-dimensional smoothed particle hydr odynamics code with radiative transfer in the flux-limited diffusion approximation. The opacities and specific heat capacities are identical for each calculation. However, we find that the temperature evolution during the simulations varies significantly when starting from different initial conditions. Even spherically-symmetric clouds with different initial densities show markedly different development. We conclude that simple barotropic equations of state like those used in some previous calculations provide at best a crude approximation to the thermal behaviour of the gas. Radiative transfer is necessary to obtain accurate temperatures.Comment: 8 pages, 9 figures, accepted for publication in MNRA

Buffet characteristics of the F-8 supercritical wing airplane

The buffet characteristics of the F-8 supercritical wing airplane were investigated. Wing structural response was used to determine the buffet characteristics of the wing and these characteristics are compared with wind tunnel model data and the wing flow characteristics at transonic speeds. The wingtip accelerometer was used to determine the buffet onset boundary and to measure the buffet intensity characteristics of the airplane. The effects of moderate trailing edge flap deflections on the buffet onset boundary are presented. The supercritical wing flow characteristics were determined from wind tunnel and flight static pressure measurements and from a dynamic pressure sensor mounted on the flight test airplane in the vicinity of the shock wave that formed on the upper surface of the wing at transonic speeds. The comparison of the airplane's structural response data to the supercritical flow characteristics includes the effects of a leading edge vortex generator

Development and production of a flame retardant, general purpose, pressure sensitive adhesive tape

The specification results for the finished tape properties were as follows: (1) adhesive strength (180 deg peel) on aluminum from 107 to 143 grams per centimeter (0.6 to 0.8 pounds per inch); (2) adhesive strength (180 deg peel) on stainless steel from 71 to 107 grams per centimeter (0.4 to 0.6 pounds per inch); (3) unwind resistance of 536 to 714 grams per centimeter (3 to 4 pounds per inch); (4) tensile strength minimum of 7143 grams per centimeter (40 pounds per inch); (5) elongation from 5 to 10% at break; (6) tear strength, Elmendorf from 200 to 350 grams (0.44 to 0.77 pounds); and (7) tear strength, tongue from 363 to 408 grams (0.8 to 0.9) pounds)

SPH Simulations of Counterrotating Disk Formation in Spiral Galaxies

We present the results of Smoothed Particle Hydrodynamics (SPH) simulations of the formation of a massive counterrotating disk in a spiral galaxy. The current study revisits and extends (with SPH) previous work carried out with sticky particle gas dynamics, in which adiabatic gas infall and a retrograde gas-rich dwarf merger were tested as the two most likely processes for producing such a counterrotating disk. We report on experiments with a cold primary similar to our Galaxy, as well as a hot, compact primary modeled after NGC 4138. We have also conducted numerical experiments with varying amounts of prograde gas in the primary disk, and an alternative infall model (a spherical shell with retrograde angular momentum). The structure of the resulting counterrotating disks is dramatically different with SPH. The disks we produce are considerably thinner than the primary disks and those produced with sticky particles. The time-scales for counterrotating disk formation are shorter with SPH because the gas loses kinetic energy and angular momentum more rapidly. Spiral structure is evident in most of the disks, but an exponential radial profile is not a natural byproduct of these processes. The infalling gas shells that we tested produce counterrotating bulges and rings rather than disks. The presence of a considerable amount of preexisting prograde gas in the primary causes, at least in the absence of star formation, a rapid inflow of gas to the center and a subsequent hole in the counterrotating disk. In general, our SPH experiments yield stronger evidence to suggest that the accretion of massive counterrotating disks drives the evolution of the host galaxies towards earlier (S0/Sa) Hubble types.Comment: To appear in ApJ. 20 pages LaTex 2-column with 3 tables, 23 figures (GIF) available at this site. Complete gzipped postscript preprint with embedded figures available from http://tarkus.pha.jhu.edu/~thakar/cr3.html (3 Mb

Inflatable device for installing strain gage bridges

Methods and devices for installing in a tubular shaft multiple strain gages are disclosed with focus on a method and a device for pneumatically forcing strain gages into seated engagement with the internal surfaces of a tubular shaft in an installation of multiple strain gages in a tubular shaft. The strain gages or other electron devices are seated in a template-like component which is wrapped about a pneumatically expansible body. The component is inserted into a shaft and the body is pneumatically expanded after a suitable adhesive was applied to the surfaces

Mind the Gap: The Integration of Physical and Mental Healthcare in Federally Qualified Health Centers

In the United States, approximately 50 percent of people experience mental illness during their lifetimes (Cunningham, 2009). However, previous studies estimate that up to 80 percent of people living with a mental illness do not access services (Mackenzie et al., 2007). While there are numerous explanations for such disparity, this study posited that stigma associated with mental illness is a significant contributory factor. In an attempt to address the gap between prevalence of mental illness and access to services, the Patient Protection and Affordable Care Act (PPACA), 2010 (US Government Printing Office, (a) 2011) mandated that Federally Qualified Health Centers (FQHCs) integrate physical and mental healthcare. This research employed case study methods to examine the implementation of this federal policy in FQHCs, focusing on what role, if any, stigma plays in such implementation. Analyzing data obtained from in-depth interviews and direct observations at two case study sites, as well as key informant interviews, and background information, this research explores the following questions: Does stigma impact the implementation of mental health policy and affect access to treatment in FQHCs for people living with mental illness? And, if stigma does impact mental health policy implementation and access to mental healthcare in FQHCs, how does this occur? Study findings include: multiple definitions of and approaches for integrating physical and mental healthcare; mental healthcare being subsumed into, rather than integrated with, the medical model; and institutional stigma persisting in the agencies studied, resulting in the reinforcement of exclusionary policies and practices and limited access to mental healthcare for FQHC patients. Empirical findings inform a new theoretical framework that identifies the role of institutional stigma in mental health policy development and implementation in FQHCs. Policy recommendations include: the adoption of non-stigmatizing practices in FQHCs; the inclusion of a single clear definition of integration within enabling legislation; restructuring of mental healthcare funding streams to facilitate agencies\u27 access to resources; and federally mandated reporting of mental health outcomes to improve FQHC accountability. These recommendations aim to promote the equitable implementation of integration policy within FQHCs and increase access to mental healthcare for those persons in need

Textbooks, Teachers, and Middle School Mathematics Student Achievement

The purpose of this study was to extend the research on textbook effectiveness to a situated investigation of a single large urban school district in which middle schools were given a choice in selecting from three textbooks for mathematics instruction: a reform textbook, a commercially produced textbook developed in response to mathematics standards, and a traditional textbook. Its genesis is rooted in the efforts in the mathematics education community to investigate the interaction of teachers and mathematics curriculum materials, but in light of the shift to an accountability policy climate in public education. In particular, this study sought to determine whether the type of textbook selected by a school, moderated by the human capital of the teachers teaching mathematics, and the interaction of those variables was associated with increased student mathematics achievement on the mathematics portion of the eighth grade statewide standardized test. Hierarchical linear modeling (HLM) was used to investigate models relating to textbook selection, components of teacher human capital, and their interaction. Contrary to the initial hypothesis, the interaction of textbook selection and components of human capital were not found to be significantly associated with student achievement. However, the selection of a reform mathematics textbook (CMP) over other more traditional texts was associated with student achievement, but accounted for very little of the variance in student test scores. To further explicate the interaction of textbook selection with school factors, logistic regression was used to investigate the association between school factors and the selection of a reform textbook. The demographics of the school (i.e. race, SES, ELL) were not associated with the school selecting a reform mathematics textbook. However, one component of teacher human capital, expertise (a component constructed from data about teacher certification, mathematics specialization, and participation in math focused professional development) was associated with the selection of a reform textbook. This study suggests there is a connection between teacher human capital, the use of reform texts and student achievement; however further investigation is needed to understand the mechanisms at work