On the linear stability of compressible plane Couette flow

The linear stability of compressible plane Couette flow is investigated. The correct and proper basic velocity and temperature distributions are perturbed by a small amplitude normal mode disturbance. The full small amplitude disturbance equations are solved numerically at finite Reynolds numbers, and the inviscid limit of these equations is then investigated in some detail. It is found that instability can occur, although the stability characteristics of the flow are quite different from unbounded flows. The effects of viscosity are also calculated, asymptotically, and shown to have a stabilizing role in all the cases investigated. Exceptional regimes to the problem occur when the wavespeed of the disturbances approaches the velocity of either of the walls, and these regimes are also analyzed in some detail. Finally, the effect of imposing radiation-type boundary conditions on the upper (moving) wall (in place of impermeability) is investigated, and shown to yield results common to both bounded and unbounded flows

Baryon and antibaryon production in hadron-hadron and hadron-nucleus interactions

Cascade baryon and anti-baryon yields have been measured in p+p and p+A collisions. After extraction of the projectile component in p+A interactions close similarities with A+A collisions concerning the nuclear enhancement factors are observed. In addition the importance of effects related to projectile isospin and to net baryon stopping is pointed out.Comment: 4 pages, 5 figures, Presented at Quark Matter 2002, Nantes, Franc

06141 Abstracts Collection -- Dynamically Reconfigurable Architectures

From 02.04.06 to 07.04.06, the Dagstuhl Seminar 06141 ``Dynamically Reconfigurable Architectures\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

The Structural Basis of Ligand Recognition by Natural Killer Cell Receptors

Natural killer cells are a group of lymphocytes which function as tightly controlled surveillance operatives which identify transformed cells through a discrete balance of activating and inhibitory receptors ultimately leading to the destruction of incongruent cells. The understanding of this finely tuned balancing act has been aided by the high-resolution structure determination of activating and inhibitory receptors both alone and in complex with their ligands. This paper collates these structural studies detailing the aspects which directly relate to the natural killer cell function and serves to inform both the specialized structural biologist reader and a more general immunology audience

Line Strengths of Rovibrational and Rotational Transitions in the X2Π^2\Pi Ground State of OH

A new line list including positions and absolute intensities (in the form of Einstein $A$ values and oscillator strengths) has been produced for the OH ground X\DP\ state rovibrational (Meinel system) and pure rotational transitions. All possible transitions are included with v\primed and v\Dprimed up to 13, and $J$ up to between 9.5 and 59.5, depending on the band. An updated fit to determine molecular constants has been performed, which includes some new rotational data and a simultaneous fitting of all molecular constants. The absolute line intensities are based on a new dipole moment function, which is a combination of two high level ab initio calculations. The calculations show good agreement with an experimental v=1 lifetime, experimental $\mu_\mathrm{v}$ values, and $\Delta$v=2 line intensity ratios from an observed spectrum. To achieve this good agreement, an alteration in the method of converting matrix elements from Hund's case (b) to (a) was made. Partitions sums have been calculated using the new energy levels, for the temperature range 5-6000 K, which extends the previously available (in HITRAN) 70-3000 K range. The resulting absolute intensities have been used to calculate O abundances in the Sun, Arcturus, and two red giants in the Galactic open and globular clusters M67 and M71. Literature data based mainly on [O I] lines are available for the Sun and Arcturus, and excellent agreement is found.Comment: 17 pages, 8 figues. 7 supplementary files: dipole moment functions (OH-X-DMFs.txt), equilibrium constants (OH-X-Equilibrium_Constants.txt), partition function (OH-X-Q_5-6000K.dat), PGOPHER file with molecular constants and transition matric elements (OH-XX.pgo), vibrational Einstein A and f values (OH-XX-Avv_fvv.txt), line list (OH-XX-Line_list.txt), and OH-Transformation_Equation_Extra.doc

Deep Well Pump Seal

Lifewater International, a Christian non-profit, trains locals to repair water well hand pumps in various third world countries. It would be beneficial to retrofit difficult-to-repair hand pumps with a locally-made pump cylinder such as HydroMission\u27s SlapShot . The majority of the components in the SlapShot can be easily obtained in rural third world villages. However, the thick leather gaskets required to seal the water cylinder during the pumping operation are imported. These thick leather gaskets are expensive, and when they fail, this results in pumps being out of commission for extended periods of time. Lifewater has presented this problem to a team of three undergraduate mechanical engineering students at California Polytechnic State University, San Luis Obispo with the goal of being able to locally source and manufacture an adequate seal to replace the current thick leather seal

Preconscious control of stereotype activation through chronic egalitarian goals

This research shows stereotype activation is controlled by chronic egalitarian goals. In the first 2 studies it was found that the stereotype of women is equally available to individuals with and without chronic goals, and the discriminant validity of the concept of egalitarian goals was established. In the next 2 experiments, differences in stereotype activation as a function of this individual difference were found. In Study 3, participants read attributes following stereotypical primes. Facilitated response times to stereotypical attributes were found for nonchronics but not for chronics. This lack of facilitation occurred at stimulus onset asynchronies (SOAs) where effortful correction processes could not operate, demonstrating preconscious control of stereotype activation due to chronic goals. In Study 4, inhibition of the stereotype was found at an SOA where effortful processes of stereotype suppression could not operate. The data reveal that goals are activated and used preconsciously to prevent stereotype activation, demonstrating both the controllability of stereotype activation and the implicit role of goals in cognitive control. The current research addresses an important question for understanding both the nature of stereotyping and the nature of cognitive control: Can one's commitment to a goal lead to control over th

On the properties of the transition matrix in bouncing cosmologies

We elaborate further on the evolution properties of cosmological fluctuations through a bounce. We show this evolution to be describable either by ``transmission'' and ``reflection'' coefficients or by an effective unitary S-matrix. We also show that they behave in a time reversal invariant way. Therefore, earlier results are now interpreted in a different perspective and put on a firmer basis.Comment: 4 pages, 1 figure, to appear in PR