High Spatial Resolution KAO Far-Infrared Observations of the Central Regions of Infrared-Bright Galaxies

We present new high spatial resolution Kuiper Airborne Observatory 50 micron and/or 100 micron data for 11 infrared-bright galaxies. We also tabulate previously published KAO data for 11 other galaxies, along with the IRAS data for the bulges of M 31 and M 81. We find that L(FIR)/L(B) and L(FIR)/L(H) correlate with CO (1 - 0) intensity and tau(100). Galaxies with optical or near-infrared signatures of OB stars in their central regions have higher values of I(CO) and tau(100), as well as higher far-infrared surface brightnesses and L(FIR)/L(B) and L(FIR)/L(H) ratios. L(FIR)/L(H(alpha)) does not correlate strongly with CO and tau(100). These results support a scenario in which OB stars dominate dust heating in the more active galaxies and older stars are important in quiescent bulges.Comment: 45 pages, to appear in Ap.J. vol. 468 (Sept. 1996). 17 postscript figures and 10 postscript tables available at ftp://ipac.caltech.edu/science/bsmith/ka

On the variance of sums of arithmetic functions over primes in short intervals and pair correlation for L-functions in the Selberg class

We establish the equivalence of conjectures concerning the pair correlation of zeros of $L$-functions in the Selberg class and the variances of sums of a related class of arithmetic functions over primes in short intervals. This extends the results of Goldston & Montgomery [7] and Montgomery & Soundararajan [11] for the Riemann zeta-function to other $L$-functions in the Selberg class. Our approach is based on the statistics of the zeros because the analogue of the Hardy-Littlewood conjecture for the auto-correlation of the arithmetic functions we consider is not available in general. One of our main findings is that the variances of sums of these arithmetic functions over primes in short intervals have a different form when the degree of the associated $L$-functions is 2 or higher to that which holds when the degree is 1 (e.g. the Riemann zeta-function). Specifically, when the degree is 2 or higher there are two regimes in which the variances take qualitatively different forms, whilst in the degree-1 case there is a single regime

Public perceptions of recycled water: a survey of visitors to the London 2012 Olympic Park

The Old Ford Water Recycling Plant, operated by Thames Water, was used to supply non-potable recycled blackwater to some of the venues at the London 2012 Games. In an effort to learn from this experience, Thames Water commissioned a survey of visitors to the Olympic Park during the Games to explore public responses to the water recycling project. Results show a very high level of support for using non-potable recycled blackwater, both in public venues and in homes. Such findings may indicate a growing receptivity towards this technology, and show that Thames Water (and other private water companies) are well placed to encourage and even lead public discussion around the role of water reuse in the future of urban water supplies

A Quantitative Study of Java Software Buildability

Researchers, students and practitioners often encounter a situation when the build process of a third-party software system fails. In this paper, we aim to confirm this observation present mainly as anecdotal evidence so far. Using a virtual environment simulating a programmer's one, we try to fully automatically build target archives from the source code of over 7,200 open source Java projects. We found that more than 38% of builds ended in failure. Build log analysis reveals the largest portion of errors are dependency-related. We also conduct an association study of factors affecting build success

A Survey of Irradiated Pillars, Globules, and Jets in the Carina Nebul

We present wide-field, deep narrowband H$_2$, Br$\gamma$, H$\alpha$, [S II], [O III], and broadband I and K-band images of the Carina star formation region. The new images provide a large-scale overview of all the H$_2$ and Br$\gamma$ emission present in over a square degree centered on this signature star forming complex. By comparing these images with archival HST and Spitzer images we observe how intense UV radiation from O and B stars affects star formation in molecular clouds. We use the images to locate new candidate outflows and identify the principal shock waves and irradiated interfaces within dozens of distinct areas of star-forming activity. Shocked molecular gas in jets traces the parts of the flow that are most shielded from the intense UV radiation. Combining the H$_2$ and optical images gives a more complete view of the jets, which are sometimes only visible in H$_2$. The Carina region hosts several compact young clusters, and the gas within these clusters is affected by radiation from both the cluster stars and the massive stars nearby. The Carina Nebula is ideal for studying the physics of young H II regions and PDR's, as it contains multiple examples of walls and irradiated pillars at various stages of development. Some of the pillars have detached from their host molecular clouds to form proplyds. Fluorescent H$_2$ outlines the interfaces between the ionized and molecular gas, and after removing continuum, we detect spatial offsets between the Br$\gamma$ and H$_2$ emission along the irradiated interfaces. These spatial offsets can be used to test current models of PDRs once synthetic maps of these lines become available.Comment: Accepted in the Astronomical Journa

Viscous relaxation and collective oscillations in a trapped Fermi gas near the unitarity limit

The viscous relaxation time of a trapped two-component gas of fermions in its normal phase is calculated as a function of temperature and scattering length, with the collision probability being determined by an energy-dependent s-wave cross section. The result is used for calculating the temperature dependence of the frequency and damping of collective modes studied in recent experiments, starting from the kinetic equation for the fermion distribution function with mean-field effects included in the streaming terms.Comment: 10 pages, 9 figures; proof version, corrected typo in Eq. (23); accepted for publication in PR

Simulating soil carbon sequestration from long term fertilizer and manure additions under continuous wheat using the DailyDayCent model

Bangabandhu Fellowship on Science and ICT project, Ministry of Science and Technology, People’s Republic of Bangladesh. Open Access via Springer Compact AgreementPeer reviewedPublisher PD

Velocity and temperature distributions of coal-slag layers on magnetohydrodynamic generators walls

Approximate analytical expressions are derived for the velocity and temperature distributions in steady state coal slag deposits flowing over MHD generator walls. Effects of slag condensation and Joule heating are included in the analysis. The transport conditions and the slag temperature at the slag-gas interface are taken to be known parameters in the formulation. They are assumed to have been predetermined either experimentally or from the slag properties and the gas dynamic calculations of the free stream flow. The analysis assumes a power law velocity profile for the slag and accounts for the coupling between the energy and momentum conservation equations. Comparisons are made with the more exact numerical solutions to verify the accuracy of the results