Water-tunnel investigation of concepts for alleviation of adverse inlet spillage interactions with external stores

A test was conducted in the NASA Langley 16- by 24-Inch Water Tunnel to study alleviation of the adverse interactions of inlet spillage flow on the external stores of a fighter aircraft. A 1/48-scale model of a fighter aircraft was used to simulate the flow environment around the aircraft inlets and on the downstream underside of the fuselage. A controlled inlet mass flow was simulated by drawing water into the inlets. Various flow control devices were used on the underside of the aircraft model to manipulate the vortical inlet spillage flow

Discharge coefficients for thick-plate orifices

Investigation enables more accurate prediction of coolant flows within internally cooled turbine blades and vanes. The data is applicable for predicting flows in complex flow passages

The Formation of Spheroids in Early-Type Spirals: Clues From Their Globular Clusters

We use deep Hubble Space Telescope images taken with the Advanced Camera for Surveys (ACS) in the F475W and F814W filters to investigate the globular cluster systems in four edge-on Sa spiral galaxies covering a factor of 4 in luminosity. The specific frequencies of the blue globular clusters in the galaxies in our sample fall in the range 0.34 -- 0.84, similar to typical values found for later-type spirals. The number of red globular clusters associated with the bulges generally increases with the bulge luminosity, similar to what is observed for elliptical galaxies, although the specific frequency of bulge clusters is a factor of 2-3 lower for the lowest luminosity bulges than for the higher luminosity bulges. We present a new empirical relation between the fraction of red globular clusters and total bulge luminosity based on the elliptical galaxies studied by ACSVCS (ACS Virgo Cluster Survey), and discuss how this diagram can be used to assess the importance that dissipative processes played in building spiral bulges. Our results suggest a picture where dissipative processes, which are expected during gas-rich major mergers, were more important for building luminous bulges of Sa galaxies, whereas secular evolution may have played a larger role in building lower-luminosity bulges in spirals.Comment: accepted for publication in Ap

Design improvement of a pump wear ring labyrinth seal

The investigation was successful in obtaining two improved designs for the impeller wear ring seal of the liquid hydrogen turbopump of interest. A finite difference computer code was extensively used in a parametric computational study in determining a cavity configuration with high flow resistance due to turbulence dissipation. These two designs, along with that currently used, were fabricated and tested. The improved designs were denoted Type O and Type S. The measurements showed that Type O and Type S given 67 and 30 percent reduction in leakage over the current design, respectively. It was found that the number of cavities, the step height and the presence of a small stator groove are quite important design features. Also, the tooth thickness is of some significance. Finally, the tooth height and an additional large cavity cut out from the stator (upstream of the step) are of negligible importance

Does language matter? Exploring Chinese-Korean differences in holistic perception

Cross-cultural research suggests that East Asians display a holistic attentional bias by paying attention to the entire field and to relationships between objects, whereas Westerners pay attention primarily to salient objects, displaying an analytic attentional bias. The assumption 20 of a universal pan-Asian holistic attentional bias has however recently been challenged in experimental research involving Japanese and Chinese participants, which suggests that linguistic factors may contribute to the formation of East Asians’ holistic attentional patterns. The present experimental research explores differences in attention and information processing styles between Korean and Chinese speakers, who have been assumed to display 25 the same attentional bias due to cultural commonalities. We hypothesize that the specific structure of the Korean language predisposes speakers to pay more attention to ground information than to figure information, thus leading to a stronger holistic attentional bias compared to Chinese speakers. Findings of the present research comparing different groups of English, Chinese, and Korean speakers provide further evidence for differences in East 30 Asians’ holistic attentional bias, which may be due to the influence of language. Furthermore, we also extend prior theorizing by discussing the potential impact of other cultural factors. In line with critical voices calling for more research investigating differences between cultures that are assumed to be culturally similar, we highlight important avenues for future studies exploring the language-culture relationship

Content of radioactive elements of the small mammal biological material in the anthropogenic impact zones and background areas

В данной статье рассматриваются особенности содержания химических элементов урана (U), и тория (Th), изученные методом инструментального нейтронно-активационного анализа, в пробах эмбриона, плаценты и печени мелкого млекопитающего вида Полевка рыжая (Myodes glareolus), отобранных около крупного медеплавильного завода (г. Ревда, Свердловская область). As the title implies the article describes a specific of content of chemical elements uranium (U), and thorium (Th), studied with Instrumental neutron-activation analysis in samples of embryo, placenta and liver of small mammal species Vole red (Myodes glareolus), sampled near large copper-smelting plant (Revda, Sverdlovsk region)

Exploring the virtual space of academia

The aim of this chapter is to provide a view on how researchers present themselves in a social network specifically developed for supporting academic practices, how they share information and engage in dialogues with colleagues worldwide. We analysed data from 30,428 users who have registered on a publicly available website to study the effect of academic position, university ranking and country on people's behaviour. Results suggest that the virtual network closely mirrors physical reality, reproducing the same hierarchical structure imposed by position, ranking, and country on user behaviour. Despite the potential for bridging and bonding social capital the networks have not achieved substantial changes in structures and practices of the academic context. Furthermore, our analysis highlights the need of finding new strategies to motivate the users to contribute to the community and support equal participation, as so far the community is mainly exploited as a static website

The Active Traveling Wave in the Cochlea

A sound stimulus entering the inner ear excites a deformation of the basilar membrane which travels along the cochlea towards the apex. It is well established that this wave-like disturbance is amplified by an active system. Recently, it has been proposed that the active system consists of a set of self-tuned critical oscillators which automatically operate at an oscillatory instability. Here, we show how the concepts of a traveling wave and of self-tuned critical oscillators can be combined to describe the nonlinear wave in the cochlea.Comment: 5 pages, 2 figure

Recent Star Formation in Sextans A

We investigate the relationship between the spatial distributions of stellar populations and of neutral and ionized gas in the Local Group dwarf irregular galaxy Sextans A. This galaxy is currently experiencing a burst of localized star formation, the trigger of which is unknown. We have resolved various populations of stars via deep UBV(RI)_C imaging over an area with diameter \sim 5.'3. We have compared our photometry with theoretical isochrones appropriate for Sextans A, in order to determine the ages of these populations. We have mapped out the history of star formation, most accurately for times \lesssim 100 Myr. We find that star formation in Sextans A is correlated both in time and space, especially for the most recent (\lesssim 12 Myr) times. The youngest stars in the galaxy are forming primarily along the inner edge of the large H I shell. Somewhat older populations, \lesssim 50 Myr, are found inward of the youngest stars. Progressively older star formation, from \sim 50--100 Myr, appears to have some spatially coherent structure and is more centrally concentrated. The oldest stars we can accurately sample appear to have approximately a uniform spatial distribution, which extends beyond a surface brightness of \mu_B \simeq 25.9 mag arcsec^{-2} (or, a radius r \simeq 2.'3$). Although other processes are also possible, our data provides support for a mechanism of supernova-driven expansion of the neutral gas, resulting in cold gas pileup and compression along the H I shell and sequential star formation in recent times.Comment: 64 pages, 22 figures, to appear in A