A Review of Restaurant Valuation Literature - The Pre 2005 Perspective

This research examines pre 2005 restaurant valuation literature in an effort to identify unexplored areas in this emerging field. Although much has been written regarding valuation in general, there has been very little appraisal literature focusing specifically on restaurants. Of the research that has been conducted, there has been some controversy about whether the appropriate value of a restaurant is a market value or a going concern value. We also explore the continuing usage of “rules of thumb” in restaurant valuation. Although these rules are often based in theory as well as practice, their breadth can severely limit their usefulness. Accordingly, we examine the prevalence of rule-of-thumb usage in the literature and hope that this may motivate academic researchers to find evidence of the relative accuracy of these informal tools

Stellar Rotation in Young Clusters. II. Evolution of Stellar Rotation and Surface Helium Abundance

We derive the effective temperatures and gravities of 461 OB stars in 19 young clusters by fitting the H-gamma profile in their spectra. We use synthetic model profiles for rotating stars to develop a method to estimate the polar gravity for these stars, which we argue is a useful indicator of their evolutionary status. We combine these results with projected rotational velocity measurements obtained in a previous paper on these same open clusters. We find that the more massive B-stars experience a spin down as predicted by the theories for the evolution of rotating stars. Furthermore, we find that the members of binary stars also experience a marked spin down with advanced evolutionary state due to tidal interactions. We also derive non-LTE-corrected helium abundances for most of the sample by fitting the He I 4026, 4387, 4471 lines. A large number of helium peculiar stars are found among cooler stars with Teff < 23000 K. The analysis of the high mass stars (8.5 solar masses < M < 16 solar masses) shows that the helium enrichment process progresses through the main sequence (MS) phase and is greater among the faster rotators. This discovery supports the theoretical claim that rotationally induced internal mixing is the main cause of surface chemical anomalies that appear during the MS phase. The lower mass stars appear to have slower rotation rates among the low gravity objects, and they have a large proportion of helium peculiar stars. We suggest that both properties are due to their youth. The low gravity stars are probably pre-main sequence objects that will spin up as they contract. These young objects very likely host a remnant magnetic field from their natal cloud, and these strong fields sculpt out surface regions with unusual chemical abundances.Comment: 50 pages 18 figures, accepted by Ap

Cloud fragmentation and proplyd-like features in HII regions imaged by HST

We have analyzed HST ACS and WFPC2 new and archival images of eight HII regions to look for new proto-planetary disks (proplyds) similar to those found in the Orion Nebula. We find a wealth of features similar in size (though many are larger) to the bright cusps around the Orion Nebula proplyds. None of them, however, contains a definitive central star. From this, we deduce that the new cusps may not be proplyds, but instead are fragments of molecular cloud material. Out of all the features found in the eight HII regions examined, only one, an apparent edge-on silhouette in M17, may have a central star. This feature might join the small number of bona fide proplyds found outside the Orion Nebula, in M8, M20 and possibly in M16. In line with the results found recently by Smith et al. (2005), the paucity of proplyds outside the Orion Nebula, may be explained by their transient nature as well as by the specific environmental conditions under whichthey can be observed.Comment: 51 pages; 19 figures; 5 tables. Accepted by A

Exact non-singular waves in the anti-de Sitter universe

A class of radiative solutions of Einstein's field equations with a negative cosmological constant and a pure radiation is investigated. The space-times, which generalize the Defrise solution, represent exact gravitational waves which interact with null matter and propagate in the anti-de Sitter universe. Interestingly, these solutions have homogeneous and non-singular wave-fronts for all freely moving observers. We also study properties of sandwich and impulsive waves which can be constructed in this class of space-times.Comment: 15 pages, 3 figures, To appear in Gen. Rel. Gra

Interpretation of the Siklos solutions as exact gravitational waves in the anti-de Sitter universe

The Siklos class of solutions of Einstein's field equations is investigated by analytical methods. By studying the behaviour of free particles we reach the conclusion that the space-times represent exact gravitational waves propagating in the anti-de Sitter universe. The presence of a negative cosmological constant implies that the 'background' space is not asymptotically flat and requires a 'rotating' reference frames in order to fully simplify and view the behaviour of nearby test particles. The Kaigorodov space-time, which is the simplest representative of the Siklos class, is analyzed in more detail. It is argued that it may serve as a 'cosmological' analogue of the well-known homogeneous pp-waves in the flat universe.Comment: 17 pages, to be published in Class. Quantum Gravit

The [O III] Veil: Astropause of Eta Carinae's Wind?

We present narrowband images of eta Carinae in the light of [O III] 5007 obtained with HST/WFPC2, as well as a ground-based image in the same emission line with a larger field of view. These images show a thin veil of [O III] emission around eta Car and its ejecta, confirming the existence of an oxygen-bearing ``cocoon'' inferred from spectra. This [O III] veil may be the remnant of the pre-outburst wind of eta Car, and its outer edge probably marks the interface where eta Car's ejecta meet the stellar wind of the nearby O4 V((f)) star HD303308 or other ambient material -- i.e., it marks the ``astropause'' in eta Car's wind. This veil is part of a more extensive [O III] shell that appears to be shaped and ionized by HD303308. A pair of HST images with a 10 yr baseline shows no proper motion, limiting the expansion speed away from eta Car to 12pm13 km/s, or an expansion age of a few times 10^4 yr. Thus, this is probably the decelerated pre-outburst LBV wind of eta Car. The [O III] morphology is very different from that seen in [N II], which traces young knots of CNO-processed material; this represents a dramatic shift in the chemical makeup of material recently ejected by eta Car. This change in the chemical abundances may have resulted from the sudden removal of the star's outer envelope during eta Car's 19th century outburst or an earlier but similar event.Comment: 11 pages, 4 figs. Figs 1 and 3 in color. Accepted to AJ, October 200

Embeddings in Non-Vacuum Spacetimes

A scheme is discussed for embedding n-dimensional, Riemannian manifolds in an (n+1)-dimensional Einstein space. Criteria for embedding a given manifold in a spacetime that represents a solution to Einstein's equations sourced by a massless scalar field are also discussed. The embedding procedures are illustrated with a number of examples.Comment: 17 pages, Plain Latex. Extended discussion on embeddings with scalar fields and further examples included. In press, Classical and Quantum Gravit

On Coupling a Lumped Parameter Heart Model and a Three-Dimensional Finite Element Aorta Model

Aortic flow and pressure result from the interactions between the heart and arterial system. In this work, we considered these interactions by utilizing a lumped parameter heart model as an inflow boundary condition for three-dimensional finite element simulations of aortic blood flow and vessel wall dynamics. The ventricular pressure–volume behavior of the lumped parameter heart model is approximated using a time varying elastance function scaled from a normalized elastance function. When the aortic valve is open, the coupled multidomain method is used to strongly couple the lumped parameter heart model and three-dimensional arterial models and compute ventricular volume, ventricular pressure, aortic flow, and aortic pressure. The shape of the velocity profiles of the inlet boundary and the outlet boundaries that experience retrograde flow are constrained to achieve a robust algorithm. When the aortic valve is closed, the inflow boundary condition is switched to a zero velocity Dirichlet condition. With this method, we obtain physiologically realistic aortic flow and pressure waveforms. We demonstrate this method in a patient-specific model of a normal human thoracic aorta under rest and exercise conditions and an aortic coarctation model under pre- and post-interventions

Inhomogeneous Einstein-Rosen String Cosmology

Families of anisotropic and inhomogeneous string cosmologies containing non-trivial dilaton and axion fields are derived by applying the global symmetries of the string effective action to a generalized Einstein-Rosen metric. The models exhibit a two-dimensional group of Abelian isometries. In particular, two classes of exact solutions are found that represent inhomogeneous generalizations of the Bianchi type VI_h cosmology. The asymptotic behaviour of the solutions is investigated and further applications are briefly discussed.Comment: Minor extension of concluding section; 18 pages, to appear in Phys.Rev.

Brane cosmology with a bulk scalar field

We consider ``cosmologically symmetric'' (i.e. solutions with homogeneity and isotropy along three spatial dimensions) five-dimensional spacetimes with a scalar field and a three-brane representing our universe. We write Einstein's equations in a conformal gauge, using light-cone coordinates. We obtain explicit solutions: a. assuming proportionality between the scalar field and the logarithm of the (bulk) scale factor; b. assuming separable solutions. We then discuss the cosmology in the brane nduced by these solutions.Comment: 24 pages, Latex, no figur