A new methodology for the quantitative visualization of coherent flow structures in alluvial channels using multibeam echo-sounding (MBES)

In order to investigate the interactions between turbulence and suspended sediment transport in natural aqueous environments, we ideally require a technique that allows simultaneous measurement of fluid velocity and sediment concentration for the whole flow field. Here, we report on development of a methodology using the water column acoustic backscatter signal from a multibeam echo sounder to simultaneously quantify flow velocities and sediment concentrations. The application of this new technique is illustrated with reference to flow over the leeside of an alluvial sand dune, which allows, for the first time in a field study, quantitative visualization of large-scale, whole flow field, turbulent coherent flow structures associated with the dune leeside that are responsible for suspending bed sediment. This methodology holds great potential for use in a wide range of aqueous geophysical flows

Polarimetric variations of binary stars. II. Numerical simulations for circular and eccentric binaries in Mie scattering envelopes

We present numerical simulations of the periodic polarimetric variations produced by a binary star placed at the center of an empty spherical cavity inside a circumbinary ellipsoidal and optically thin envelope made of dust grains. Mie single-scattering is considered along with pre- and post-scattering extinction factors which produce a time-varying optical depth and affect the morphology of the periodic variations. We are interested in the effects that various parameters will have on the average polarization, the amplitude of the polarimetric variations, and the morphology of the variability. We show that the absolute amplitudes of the variations are smaller for Mie scattering than for Thomson scattering. Among the four grain types that we have studied, the highest polarizations are produced by grains with sizes in the range 0.1-0.2 micron. In general, the variations are seen twice per orbit. In some cases, because spherical dust grains have an asymmetric scattering function, the polarimetric curves produced also show variations seen once per orbit. Circumstellar disks produce polarimetric variations of greater amplitude than circumbinary envelopes. Another goal of these simulations is to see if the 1978 BME (Brown, McLean, & Emslie, ApJ, 68, 415) formalism, which uses a Fourier analysis of the polarimetric variations to find the orbital inclination for Thomson-scattering envelopes, can still be used for Mie scattering. We find that this is the case, if the amplitude of the variations is sufficient and the true inclinations is i_true > 45 deg. For eccentric orbits, the first-order coefficients of the Fourier fit, instead of second-order ones, can be used to find almost all inclinations.Comment: 23 pages, 5 figures, to be published in Astronomical Journa

A Field Guide to Cancellation of Debt Income

The United States is awash in a sea of debt. In the midst of the most severe recession since the Great Depression, loan delinquencies and charge-offs are at levels heretofore unknown in the modern financial era. Every loan charge-off and mortgage foreclosure has tax consequences. While the creditor most often claims a bad debt deduction or business related loss, the debtor generally must recognize gross income and pay income taxes on an amount roughly equal to the creditor’s loss, unless a special exception applies to exclude the debt relief from income. This article deals with the tax consequences to the debtor of the discharge of a debt for less than full payment. It first explain the origins and rationale for the rule, now codified in § 61(a)(12), that requires the inclusion of \u27[i]ncome from discharge of indebtedness.\u27 The article then examines the various events that trigger recognition of income under § 61(a)(12). Following that discussion, the article deals with the manner in which the amount of income from discharge of indebtedness is computed. This part of the article also discusses the tax consequences to a business entity that issues an equity interests to a creditor to satisfy a debt. Finally, the article explores the myriad of statutory rules in §108 that permit nonrecognition income from discharge of indebtedness under particular circumstances, and the various ancillary consequences that follow from nonrecognition. Throughout, the article explores the relationship of income from discharge of indebtedness to realization of gain from the transfer of property to satisfy a debt by contrasting the tax consequences of transfers of property to discharge a debt with the consequences of discharge of a debt for less than full payment

When Subchapter S Meets Subchapter C

It is often said that “an S corporation is a corporation that is taxed like a partnership.” This statement is incorrect. An S corporation resembles a partnership only in that it generally does not pay income taxes and its income and losses pass through to the shareholders and retain their character as they pass through. Also, like a partnership, basis adjustments to an S corporation shareholder\u27s stock reflect allocations of income, expense, loss, and distributions. However, no other rules of subchapter K governing partnership taxation apply to S corporations. Most of the rules governing the relationship between an S corporation and its shareholders differ significantly from the rules governing the relationship between a partnership and its partners. In fact, an S corporation and its shareholders are subject to the rules of subchapter C, just like a corporation that has not made an S election, with very few exceptions. This Article highlights some of the major differences between taxation of S corporations and taxation of partnerships and explores in greater detail the intersection of subchapter C with subchapter S with respect to transactional issues, such as formation of the corporation, redemptions, liquidations, and mergers and acquisitions of and by S corporations, as well as similar issues regarding qualified subchapter S subsidiaries

A Field Guide to Cancellation of Debt Income

The United States is awash in a sea of debt. In the midst of the most severe recession since the Great Depression, loan delinquencies and charge-offs are at levels heretofore unknown in the modern financial era. Every loan charge-off and mortgage foreclosure has tax consequences. While the creditor most often claims a bad debt deduction or business related loss, the debtor generally must recognize gross income and pay income taxes on an amount roughly equal to the creditor’s loss, unless a special exception applies to exclude the debt relief from income. This article deals with the tax consequences to the debtor of the discharge of a debt for less than full payment. It first explain the origins and rationale for the rule, now codified in § 61(a)(12), that requires the inclusion of \u27[i]ncome from discharge of indebtedness.\u27 The article then examines the various events that trigger recognition of income under § 61(a)(12). Following that discussion, the article deals with the manner in which the amount of income from discharge of indebtedness is computed. This part of the article also discusses the tax consequences to a business entity that issues an equity interests to a creditor to satisfy a debt. Finally, the article explores the myriad of statutory rules in §108 that permit nonrecognition income from discharge of indebtedness under particular circumstances, and the various ancillary consequences that follow from nonrecognition. Throughout, the article explores the relationship of income from discharge of indebtedness to realization of gain from the transfer of property to satisfy a debt by contrasting the tax consequences of transfers of property to discharge a debt with the consequences of discharge of a debt for less than full payment