An evaluation of the post-ignition unblocking behavior of solid propellant aft-end ignition systems Final report

Determining postignition interactions between igniter and main motor flow by aft-end heated air simulation of solid propellant exhaus

Heralded Two-Photon Entanglement from Probabilistic Quantum Logic Operations on Multiple Parametric Down-Conversion Sources

An ideal controlled-NOT gate followed by projective measurements can be used to identify specific Bell states of its two input qubits. When the input qubits are each members of independent Bell states, these projective measurements can be used to swap the post-selected entanglement onto the remaining two qubits. Here we apply this strategy to produce heralded two-photon polarization entanglement using Bell states that originate from independent parametric down-conversion sources, and a particular probabilistic controlled-NOT gate that is constructed from linear optical elements. The resulting implementation is closely related to an earlier proposal by Sliwa and Banaszek [quant-ph/0207117], and can be intuitively understood in terms of familiar quantum information protocols. The possibility of producing a ``pseudo-demand'' source of two-photon entanglement by storing and releasing these heralded pairs from independent cyclical quantum memory devices is also discussed.Comment: 5 pages, 4 figures; submitted to IEEE Journal of Selected Topics in Quantum Electronics, special issue on "Quantum Internet Technologies

Why Do CEO's Reciprocally Sit On Each Other's Boards?

The reciprocal interlocking of chief executive officers (CEOs) is a non-trivial phenomenon of the composition of boards of directors and of corporate governance: among large companies in 1991, about one company in seven is part of a relationship whereby the CEO of one company sits on a second company's board and the second company's CEO sits on the first company's board. We are aware of no previous efforts to explain these reciprocal relationships. We hypothesize that reciprocal CEO interlocks are (a) more likely when a board has more outside directorships, (b) less likely when a CEO has more of his total annual compensation paid in the form of stock options, (c) less likely when a company's board is more active and holds more meetings, (d) less likely when a CEO has a larger ownership share of his company, and (e) more likely when there are more CEOs from other companies as outside directors on a CEO's board. Using a sizable sample of large companies in 1991, we employ simple probit and step probit models to test these hypotheses, with the use of control variables that encompass other company, board, and CEO characteristics. These multivariate analyses support our first three conjectures but do not support the remaining two. Since there is considerable academic and policy debate concerning board composition and the effectiveness of interlocking directorships in general, investigations focusing on reciprocal CEO interlocks, which link the highest ranked executives of two different firms, represent a significant contribution to the knowledge base in this field

Variable temperature study of the crystal and magnetic structures of the giant magnetoresistant materials LMnAsO (L=La, Nd)

Peer reviewedPublisher PD

A comparison between conventional and LANDSAT based hydrologic modeling: The Four Mile Run case study

Models designed to support the hydrologic studies associated with urban water resources planning require input parameters that are defined in terms of land cover. Estimating the land cover is a difficult and expensive task when drainage areas larger than a few sq. km are involved. Conventional and LANDSAT based methods for estimating the land cover based input parameters required by hydrologic planning models were compared in a case study of the 50.5 sq. km (19.5 sq. mi) Four Mile Run Watershed in Virginia. Results of the study indicate that the LANDSAT based approach is highly cost effective for planning model studies. The conventional approach to define inputs was based on 1:3600 aerial photos, required 110 man-days and a total cost of $14,000. The LANDSAT based approach required 6.9 man-days and cost$2,350. The conventional and LANDSAT based models gave similar results relative to discharges and estimated annual damages expected from no flood control, channelization, and detention storage alternatives