11,482 research outputs found
Collision integrals and high temperature transport properties for N-N, O-O, and N-O
Accurate collision integrals are reported for the interactions of N(4 S 0) + N(4 S 0), O(3 P), and N(4 S 0) + O(3 P). These are computed from a semiclassical formulation of the scattering using the best available representations of all of the potential energy curves needed to describe the collisions. Experimental RKR curves and other accurate measured data are used where available; the results of accurate ab initio electronic structure calculations are used to determine the remaining potential curves. The high-lying states are found to give the largest contributions to the collision cross sections. The nine collision integrals, needed to determine transport properties to second order, are tabulated for translational temperatures in the range 250 K to 100,000 K. These results are intended to reduce the uncertainty in future predictions of the transport properties of nonequilibrium air, particularly at high temperatures. The viscosity, thermal conductivity, diffusion coefficient, and thermal diffusion factor for a gas composed of nitrogen and oxygen atoms in thermal equilibrium are calculated. It was found that the second order contribution to the transport properties is small. Graphs of these transport properties for various mixture ratios are presented for temperatures in the range 5000 to 15000 K
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Prototyping a process-centered environment
This paper describes an experimental system developed and used as a vehicle for prototyping the Arcadia-1 software development environment. Prototyping is viewed as a knowledge acquisition process and is used to reduce risks in software development by gaining rapid feedback about the suitability of a production system before the system is completed. Prototyping a software development environment is particularly important due to the lack of experience with them. There is an acute need to acquire knowledge about user interaction requirements for software environments. These needs are especially important for the Arcadia project, as it is one of the first attempts to construct a process-centered environment. Our prototyping effort addresses questions about effective interaction with a process-centered environment by simulating how Arcadia-1 would interact with users in a representative range of usage scenarios. We built a prototyping system, called PRODUCER, and used it to generate a variety of prototypes simulating user interactions with Arcadia-1 process programs.Experience with PRODUCER indicates that our approach is effective at risk reduction. The prototypes greatly improved communication with our customer. They confirmed some of our design decisions but also redirected our research efforts as a result of unexpected insight. We also found that prototyping usage scenarios provides conceptual guides and design information for process programmers. Most of the benefits of our prototyping effort derive from developing and interacting with usage scenarios, so our approach is generalizable to other prototyping systems. This paper reports on our prototyping approach and our experience in prototyping a process-centered environment
A Lightweight Loudspeaker for Aircraft Communications and Active Noise Control
A series of new, lightweight loudspeakers for use on commercial aircraft has been developed. The loudspeakers use NdFeB magnets and aluminum alloy frames to reduce the weight. The NdFeB magnet is virtually encapsulated by steel in the new speaker designs. Active noise reduction using internal loudspeakers was demonstrated to be effective in 1983. A weight, space, and cost efficient method for creating the active sound attenuating fields is to use the existing cabin loudspeakers for both communication and sound attenuation. This will require some additional loudspeaker design considerations
The effect of maternal iron deficiency on zinc and copper levels and on genes of zinc and copper metabolism during pregnancy in the rat
Fe deficiency is relatively common in pregnancy and has both short- and long-term consequences. However, little is known about the effect on the metabolism of other micronutrients. A total of fifty-four female rats were fed control (50 mg Fe/kg) or Fe-deficient diets (7·5 mg/kg) before and during pregnancy. Maternal liver, placenta and fetal liver were collected at day 21 of pregnancy for Cu and Zn analysis and to measure expression of the major genes of Cu and Zn metabolism. Cu levels increased in the maternal liver (P=0·002) and placenta (P=0·018) of Fe-deficient rats. Zn increased (P<0·0001) and Cu decreased (P=0·006) in the fetal liver. Hepatic expression of the Cu chaperones antioxidant 1 Cu chaperone (P=0·042) and cytochrome c oxidase Cu chaperone (COX17, P=0·020) decreased in the Fe-deficient dams, while the expression of the genes of Zn metabolism was unaltered. In the placenta, Fe deficiency reduced the expression of the chaperone for superoxide dismutase 1, Cu chaperone for superoxide dismutase (P=0·030), ceruloplasmin (P=0·042) and Zn transport genes, ZRT/IRT-like protein 4 (ZIP4, P=0·047) and Zn transporter 1 (ZnT1, P=0·012). In fetal liver, Fe deficiency increased COX17 (P=0·020), ZRT/IRT-like protein 14 (P=0·036) and ZnT1 (P=0·0003) and decreased ZIP4 (P=0·004). The results demonstrate that Fe deficiency during pregnancy has opposite effects on Cu and Zn levels in the fetal liver. This may, in turn, alter metabolism of these nutrients, with consequences for development in the fetus and the neonate.</p
The Distribution of Lya-Emitting Galaxies at z=2.3
We present the detection of 34 Ly-alpha emission-line galaxy candidates in a
80x80x60 co-moving Mpc region surrounding the known z=2.38 galaxy cluster
J2143-4423. The space density of Ly-alpha emitters is comparable to that found
by Steidel et al. when targeting a cluster at redshift 3.09, but is a factor of
5.8 +/- 2.5 greater than that found by field samples at similar redshifts. The
distribution of these galaxy candidates contains several 5-10 Mpc scale voids.
We compare our observations with mock catalogs derived from the VIRGO
consortium Lambda-CDM n-body simulations. Fewer than 1% of the mock catalogues
contain voids as large as we observe. Our observations thus tentatively suggest
that the galaxy distribution at redshift 2.38 contains larger voids than
predicted by current models. Three of the candidate galaxies and one previously
discovered galaxy have the large luminosities and extended morphologies of
"Ly-alpha blobs".Comment: 10 pages, 8 figures, emulateapj5, Accepted for publication in Ap
Long-range electron transfer in structurally engineered pentaammineruthenium (histidine-62) cytochrome c
In many biological processes, long-range electron transfer (ET) plays a key role. When the three-dimensional structures of proteins are accurately known, use of modified proteins and protein-protein complexes provides an experimental approach to study ET rates between two metal centers. For Ru(His)- modified proteins, the introduction of histidine residues at any desired surface location by site-directed mutagenesis opens the way for systematic investigations of ET pathways
What does not happen: quantifying embodied engagement using NIMI and self-adaptors
Previous research into the quantification of embodied intellectual and emotional engagement using non-verbal movement parameters has not yielded consistent results across different studies. Our research introduces NIMI (Non-Instrumental Movement Inhibition) as an alternative parameter. We propose that the absence of certain types of possible movements can be a more holistic proxy for cognitive engagement with media (in seated persons) than searching for the presence of other movements. Rather than analyzing total movement as an indicator of engagement, our research team distinguishes between instrumental movements (i.e. physical movement serving a direct purpose in the given situation) and non-instrumental movements, and investigates them in the context of the narrative rhythm of the stimulus. We demonstrate that NIMI occurs by showing viewers’ movement levels entrained (i.e. synchronised) to the repeating narrative rhythm of a timed computer-presented quiz. Finally, we discuss the role of objective metrics of engagement in future context-aware analysis of human behaviour in audience research, interactive media and responsive system and interface design
GENERIC ADVERTISING WEAROUT: THE CASE OF THE NEW YORK CITY FLUID MILK CAMPAIGN
This article examines two major generic fluid milk advertising campaigns in New York City during the 1986-92 period. Estimates from a time-varying parameter model show that the evolution of the impact of generic advertising on fluid milk sales over each campaign followed a bell-shaped pattern. Results also show that the first campaign was effective for twice as long as the second campaign and that it has a higher peak and higher average advertising elasticity. These findings may reflect long-term generic milk advertising wearout in the New York City market.Marketing,
Some Legislative History and Comments on Ohio\u27s New Criminal Code
Having briefly outlined the history of the formal development of the Act, it is the purpose of this Article to discuss in narrative form the legislative process on certain key provisions which were the subject of much debate and disagreement. These areas of disagreement include murder and felony penalties, especially minimum sentences; capital punishment to conform to the U.S. Supreme Court\u27s Furman decision as well as other changes; parole eligibility for those serving life sentences for a capital offense; early release on parole, also known as shock parole; eligibility for probation; definition of reasonable doubt and jury instructions on reasonable doubt; eventual rejection of seven affirmative defenses which the legislature decided to leave to case law; expanding the definition of rape and creating new sex offenses, such as gross sexual imposition and other changes to sex offense statutes
A time series feature of variability to detect two types of boredom from motion capture of the head and shoulders
Boredom and disengagement metrics are crucial to the correctly timed implementation of adaptive interventions in interactive systems. psychological research suggests that boredom (which other HCI teams have been able to partially quantify with pressure-sensing chair mats) is actually a composite: lethargy and restlessness. Here we present an innovative approach to the measurement and recognition of these two kinds of boredom, based on motion capture and video analysis of changes in head and shoulder positions. Discrete, three-minute, computer-presented stimuli (games, quizzes, films and music) covering a spectrum from engaging to boring/disengaging were used to elicit changes in cognitive/emotional states in seated, healthy volunteers. Interaction with the stimuli occurred with a handheld trackball instead of a mouse, so movements were assumed to be non-instrumental. Our results include a feature (standard deviation of windowed ranges) that may be more specific to boredom than mean speed of head movement, and that could be implemented in computer vision algorithms for disengagement detection
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