Impact of future HERA data on the determination of proton parton distribution functions using the ZEUS QCD fit

The high precision and large kinematic coverage of the data from the HERA-I running period (1994-2000) have already allowed precise extractions of proton parton distribution functions (PDFs). The HERA-II running program is now underway and is expected to provide a substantial increase in the luminosity collected at HERA. In this paper, a study is presented which investigates the potential impact of future data from HERA on the proton PDF uncertainties, within the currently planned running scenario. In addition, the effect of a possible future measurement of the longitudinal structure function, FL, on the gluon distribution is investigated.Comment: 5 pages, 2 figures, in proceedings of the XIII International Workshop on Deep Inelastic Scattering - DIS 2005, Madison, Wisconsin, 200

Searching a biomedical bibliographic database from the Ukraine: the Panteleimon database

The Panteleimon database is available via the Internet and is a public access, database, capable of being searched in English, Russian and Ukrainian, covering medical, pharmaceutical, and chemical publications, published in he Ukraine and Russia from 1998. Describes the formulation of a search strategy for the Panteleimon database, for the identification of citations to randomized controlled trials (RCTs), and the comparison of the search results with records included in the Cochrane Library's Cochrane Central Register of Controlled Trials (CENTRAL) database, to evaluate how comprehensive the coverage of the CENTRAL database is for the literature of the Ukraine. The results indicated that Panteleimon is an easily accessible bibliographic database offering easy access to the Ukrainian biomedical literature. The English language retrieval functions picked up most of the reports of RCTs/CCTs (91 per cent precision but the lower recall of 55 per cent indicates the need to search using Russian and Ukrainian terms for completeness. The overall precision of 26 per cent compares favourably with a search for RCTs in EMBASE, carried out by the UK Cochrane Centre, where 70,000 reports of RCTs were identified from 300,000 records down-loaded (precision 23 per cent). (Quotes from original text

The Ultimate Halo Mass in a LCDM Universe

In the far future of an accelerating LCDM cosmology, the cosmic web of large-scale structure consists of a set of increasingly isolated halos in dynamical equilibrium. We examine the approach of collisionless dark matter to hydrostatic equilibrium using a large N-body simulation evolved to scale factor a = 100, well beyond the vacuum--matter equality epoch, a_eq ~ 0.75, and 53/h Gyr into the future for a concordance model universe (Omega_m ~ 0.3, Omega_Lambda ~ 0.7). The radial phase-space structure of halos -- characterized at a < a_eq by a pair of zero-velocity surfaces that bracket a dynamically active accretion region -- simplifies at a > 10 a_eq when these surfaces merge to create a single zero-velocity surface, clearly defining the halo outer boundary, rhalo, and its enclosed mass, mhalo. This boundary approaches a fixed physical size encompassing a mean interior density ~ 5 times the critical density, similar to the turnaround value in a classical Einstein-deSitter model. We relate mhalo to other scales currently used to define halo mass (m200, mvir, m180b) and find that m200 is approximately half of the total asymptotic cluster mass, while m180b follows the evolution of the inner zero velocity surface for a < 2 but becomes much larger than the total bound mass for a > 3. The radial density profile of all bound halo material is well fit by a truncated Hernquist profile. An NFW profile provides a somewhat better fit interior to r200 but is much too shallow in the range r200 < r < rhalo.Comment: 5 pages, 3 figures, submitted to MNRAS letter

Hexagonal spiral growth in the absence of a substrate

Experiments on the formation of spiraling hexagons (350 - 1000 nm in width) from a solution of nanoparticles are presented. Transmission electron microscopy images of the reaction products of chemically synthesized cadmium nanocrystals indicate that the birth of the hexagons proceeds without assistance from static screw or edge dislocatons, that is, they spiral without constraints provided by an underlying substrate. Instead, the apparent growth mechanism relies on what we believe is a dynamical dislocation identified as a dense aggregate of small nanocrystals that straddles the spiraling hexagon at the crystal surface. This nanocrystal bundle, which we term the "feeder", also appears to release nanocrystals into the spiral during the growth process.Comment: 4 pages, 5 figure

Nondestructive testing of brazed rocket engine components

Report details study made of nondestructive radiographic, ultrasonic, thermographic, and leak test methods used to inspect and evaluate the quality of the various brazed joints in liquid-propellant rocket engine components and assemblies. Descriptions of some of the unique equipment and methods developed are included

The quiescent progenitors of four Type II-P/L supernovae

We present Large Binocular Telescope difference imaging data for the final years of four Type II-P/L supernovae progenitors. For all four, we find no significant evidence for stochastic or steady variability in the U, B, V, or R-bands. Our limits constrain variability to no more than roughly 5-10% of the expected R-band luminosities of the progenitors. These limits are comparable to the observed variability of red supergiants in the Magellanic Clouds. Based on these four events, the probability of a Type II-P/L progenitor having an extended outburst after Oxygen ignition is <37% at 90% confidence. Our observations cannot exclude short outbursts in which the progenitor returns to within ~10% of its quiescent flux on the time scale of months with no dust formation.Comment: 9 pages, 8 figures, 1 table. Accepted to MNRA

Production mechanisms and single-spin asymmetry for kaons in high energy hadron-hadron collisions

Direct consequences on kaon production of the picture proposed in a recent Letter and subsequent publications are discussed. Further evidence supporting the proposed picture is obtained. Comparison with the data for the inclusive cross sections in unpolarized reactions is made. Quantitative results for the left-right asymmetry in single-spin processes are presented.Comment: 10 pages, 2 Postscript figure