10,228 research outputs found
The Harlem Children's Zone, Promise Neighborhoods, and the Broader, Bolder Approach to Education
Examines the role of community services in raising academic achievement in the Harlem Children's Zone. Questions the effectiveness of replicating the neighborhood approach, rather than the schools-only approach, in the Promise Neighborhoods Initiative
Comparing the penetrative stab performance of the UK HOSDB P1/B and Stanley Tools 1992 trimming blades on certified body armour specimens
This body of research assessed the penetrative stab performance of the United Kingdom Home
Office Scientific Development Branch’s (HOSDB) P1/B certified blades against the readily accessible
Stanley Tools 1992 trimming blade. All tests were performed against the HOSDB KR1-E1 impact
energy of 24 Joules on HOSDB KR1 certified body armour specimens. Results demonstrated that the
Stanley 1992 trimming blade posed a 30% greater stab threat in comparison to the HOSDB P1/B
blade.
This paper demonstrates the threat imposed by readily available utility blades and a requirement to
enhance existing body stab resistant body armour test procedures testing procedures
Fees and Surcharging in automatic teller machine networks: Non-bank ATM providers versus large banks
This paper develops a spacial model of ATM networks to explore the implications for banks and non-banks of interchange fees, foreign fees and surcharges applied to transactions by customers at other than an own-bank ATM. Surcharging raises the price (foreign fee plus surcharge) paid by customers above the joint profit-maximizing level achieved by setting the interchange fee at marginal cost and not surcharging. Similar size banks would agree not to surcharge, but such an agreement is typically not possible between a bank and a non-bank. A high cost of teller transactions modifies the tendency towards high ATM fees.
Lyman-alpha forest-CMB cross-correlation and the search for the ionized baryons at high redshift
The intergalactic neutral hydrogen which is responsible for the Lyman alpha
forest of quasar absorption is a tracer of much larger amounts of ionised
hydrogen. The ionised component has yet to be detected directly, but is
expected to scatter CMB photons via the Sunyaev-Zel'dovich (SZ) effect. We use
hydrodynamic simulations of a LambdaCDM universe to create mock quasar spectra
and CMB sky maps. We find that the high-z Lya forest gas causes temperature
fluctuations of the order of 1 muK rms in the CMB on arcmin scales. The kinetic
and thermal SZ effects have a similar magnitude at z=3, with the thermal effect
becoming relatively weaker as expected at higher z. The CMB signal associated
with lines of sight having HI column densities > 10^18 cm^-2 is only marginally
stronger than that for lower column densities. The strong dependence of rms
temperature fluctuation on mean Lya absorbed flux, however, suggests that the
CMB signal effectively arises in lower density material. We investigate the use
of the cross-correlation of the Lya forest and the microwave background to
detect the SZ effect at redshifts 2-4. In so doing we are able to set direct
limits on the density of diffuse ionised intergalactic baryons. We carry out a
preliminary comparison at a mean redshift z=3 of 3488 quasar spectra from SDSS
Data Release 3 and the WMAP first year data. Assuming that the baryons are
clustered as in a LambdaCDM cosmology, and have the same mean temperature, the
cross-correlation yields a weak limit on the cosmic density of ionised baryons
Omega_(b,I), which is Omega_(b,I) < 0.8 at 95% confidence. With data from
upcoming CMB telescopes, we anticipate that a direct detection of the high
redshift ionised IGM will soon be possible, providing an important consistency
check on cosmological models.Comment: 14 pages, 10 figures, submitted to MNRA
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