Electrical impedance imaging in two-phase, gas-liquid flows: 1. Initial investigation

The determination of interfacial area density in two-phase, gas-liquid flows is one of the major elements impeding significant development of predictive tools based on the two-fluid model. Currently, these models require coupling of liquid and vapor at interfaces using constitutive equations which do not exist in any but the most rudimentary form. Work described herein represents the first step towards the development of Electrical Impedance Computed Tomography (EICT) for nonintrusive determination of interfacial structure and evolution in such flows

Evaluation of Formal posterior distributions via Markov chain arguments

We consider evaluation of proper posterior distributions obtained from improper prior distributions. Our context is estimating a bounded function $\phi$ of a parameter when the loss is quadratic. If the posterior mean of $\phi$ is admissible for all bounded $\phi$, the posterior is strongly admissible. We give sufficient conditions for strong admissibility. These conditions involve the recurrence of a Markov chain associated with the estimation problem. We develop general sufficient conditions for recurrence of general state space Markov chains that are also of independent interest. Our main example concerns the $p$-dimensional multivariate normal distribution with mean vector $\theta$ when the prior distribution has the form $g(\|\theta\|^2) d\theta$ on the parameter space $\mathbb{R}^p$. Conditions on $g$ for strong admissibility of the posterior are provided.Comment: Published in at http://dx.doi.org/10.1214/07-AOS542 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

First-principles Calculations of Engineered Surface Spin Structures

The engineered spin structures recently built and measured in scanning tunneling microscope experiments are calculated using density functional theory. By determining the precise local structure around the surface impurities, we find the Mn atoms can form molecular structures with the binding surface, behaving like surface molecular magnets. The spin structures are confirmed to be antiferromagnetic, and the exchange couplings are calculated within 8% of the experimental values simply by collinear-spin GGA+U calculations. We can also explain why the exchange couplings significantly change with different impurity binding sites from the determined local structure. The bond polarity is studied by calculating the atomic charges with and without the Mn adatoms

Don’t Presume the Presumption Has Been Applied Properly

In recognition of the humanitarian purpose of the District of Columbia Workers’ Compensation Act of 1979, D.C. Code as amended, §32-1501 et seq. and the legislative policy favoring awards even in arguable cases, a claimant is entitled to a presumption of compensability (“Presumption”) when applying for workers’ compensation benefits. By establishing a causal connection between the injured worker’s disability and a work-related event, the Presumption enables a claimant to establish entitlement to benefits more easily; however, an analysis of decisions issued by the Compensation Review Board from 2005 – 2019 reveals the Presumption frequently is misapplied. For example, the aggressor defense in work-related fight cases requires the claimant prove a connection between employment and the altercation, but despite the fact that proving the first prong of the Bird test satisfies the requirements for invoking the Presumption, if the claimant started the fight the claim is not compensable. Similarly, misapplication of the Presumption makes it more difficult for claimants to prove work-related psychological injuries because they must satisfy additional requirements (including a credibility requirement) not imposed on claimants who sustain physical injuries even though when invoking the Presumption any suspicion of deception should apply equally to both types of injuries. Moreover, contrary to Marc Galanter’s position in Why the “Haves” Come Out Ahead: Speculations on the Limits of Legal Change, in District of Columbia private sector workers’ compensation cases, One-Shotter-Claimants (Have-Nots) have distinct advantages built into the architecture of the system, not the least of which is the Presumption, yet despite the advantages, because misapplication of the Presumption has little effect on the outcome of remanded cases, the Repeat-Player-Employers (the Haves) continue to come out ahead

Taking payments online: A framework for selection

Electronic bill presentment and payment (EBPP) is usually viewed as a killer application in e-commerce, which will fundamentally change the way customers receive and pay their bills. While many models exist, there is a dearth of information for determining which model would best fit customer characteristics and needs. This paper examines primary models, customer requirements, bill characteristics, and customer types to develop an exploratory framework for determviing which EBPP model a bill-generating firm should employ

The first measurement of BB meson semi-leptonic decay contribution to non-photonic electrons at RHIC

We present the first measurement for the $B$ meson semi-leptonic decay contribution to non-photonic electrons at RHIC using non-photonic electron azimuthal correlations with charged hadrons in p+p collisions at $\sqrt{s_{NN}} = 200$ GeV from STAR.Comment: 4 pages, 3 figures, Quark Matter 2006 Proceedings, to appear in J. Phys.