Nuclear halo structure from quasielastic charge-exchange reactions

Neutron and proton densities in the nuclear periphery are investigated within (p,n) charge-exchange isobar transitions. For this purpose we have developed parameter-free optical potentials with a detailed treatment of the in-medium $t_{\tau}$ part of the effective interaction. Non local coupled-channel Lane equations are solved to obtain the scattering observables. The use of conventional proton and neutron densities significantly underestimates Fermi (forward-angle) cross-sections in agreement with findings by various other groups. However, we have found model-independent densities which provide a remarkable improvement in the description of the quasielastic scattering data.The densities obtained are consistent with recent measurements at CERN in studies of the neutron-to-proton halo factor f(r)=Z$\rho_n/N\rho_p$ with antiprotons. These findings provide an alternative way to investigate the nuclear periphery, and may also help to solve the long-standing puzzle of the underestimated Fermi cross section in (p,n) charge-exchange phenomena.Comment: 5 pages and 2 figs. Presented at the Baryons-04 Conference (Palaiseau, France, Oct 2004). To appear in Nucl. Phys.

An in-medium full-folding model approach to quasielastic (p,n) charge-exchange reactions

A microscopic description of the quasielastic (p,n) charge-exchange reaction (here, charge-exchange scattering between analogue states) is presented and discussed. Emphasis is focused on the spin-isospin structure of the projectile-target coupling. The model is a coupled-channel extension of the full-folding optical model approach (OMP) developed for nucleon elastic scattering, where emphasis is placed on retaining the genuine off-shell behavior of realistic effective interactions in the nuclear medium. The resulting non-local optical potentials are applied to the calculation of (p,n) differential cross sections, with particular emphasis on small-angle Fermi ($\Delta S=0$) cross-sections to isobaric analog states. These parameter-free results provide a reasonable description of the $^{14}$C(p,n)-data at proton energies above $\sim$100 MeV, but deteriorate for heavier targets. These shortcomings are analyzed and possible ways to correct them are discussed.Comment: 20 pages plus 10 figures. Accepted for publication in Phys. Rev.

Corporate governance, investor protection, and performance in emerging markets

Recent research studying the link between law, and finance has concentrated on country-level investor protection measures, and focused on differences in legal systems across countries, and legal families. The authors extend this literature, and provide a study of firm-level corporate governance practices across emerging markets, and a greater understanding of the environments under which corporate governance matters more. Their empirical tests show that better corporate governance is highly correlated with better operating performance, and market valuation. More important, the authors provide evidence showing that firm-level corporate governance provisions, matter more in countries with weak legal environments. These results suggest that firms can partially compensate for ineffective laws, and enforcement by establishing good governance, and providing credible investor protection. The authors'tests also show that firm-level governance, and performance is lower in countries with weak legal environments, suggesting that improving the legal system, should remain a priority for policymakers.Financial Crisis Management&Restructuring,International Terrorism&Counterterrorism,Municipal Financial Management,Decentralization,Banks&Banking Reform,Governance Indicators,National Governance,Banks&Banking Reform,Financial Crisis Management&Restructuring,Economic Policy, Institutions and Governance

The impact of the business environment on young firm financing

This paper uses a dataset of more than 70,000 firms in over 100 countries to systematically study the use of different financing sources for new and young firms, in comparison to mature firms. The authors find that in all countries younger firms rely less on bank financing and more on informal financing. However, they also find that younger firms use more bank finance in countries with stronger rule of law and better credit information, and that the reliance of young firms on informal finance decreases with the availability of credit information. Overall, the results suggest that improvements to the legal environment and availability of credit information are disproportionately beneficial for promoting access to formal finance by young firms.Access to Finance,Debt Markets,Bankruptcy and Resolution of Financial Distress,Banks&Banking Reform,Financial Intermediation

Method of fan sound mode structure determination computer program user's manual: Modal calculation program

A computer user's manual describing the operation and the essential features of the Modal Calculation Program is presented. The modal Calculation Program calculates the amplitude and phase of modal structures by means of acoustic pressure measurements obtained from microphones placed at selected locations within the fan inlet duct. In addition, the Modal Calculation Program also calculates the first-order errors in the modal coefficients that are due to tolerances in microphone location coordinates and inaccuracies in the acoustic pressure measurements

Method of fan sound mode structure determination computer program user's manual: Microphone location program

A computer user's manual describing the operation and the essential features of the microphone location program is presented. The Microphone Location Program determines microphone locations that ensure accurate and stable results from the equation system used to calculate modal structures. As part of the computational procedure for the Microphone Location Program, a first-order measure of the stability of the equation system was indicated by a matrix 'conditioning' number

Real #HotGirl Sh*T: Practical application of intersectional re-presentation instruction

This critical commentary outlines how the Real #HotGirl Sh*T: Megan Thee Stallion & Mediated Hip Hop, Black Feminist and Communication Pedagogy promotes active learning via popular culture and digital media, and it provides a practical model for employing intersectionality in classroom settings. Previous critical media pedagogy exploring minority media re-presentation primarily focused on the effects of master narratives produced by traditional media. This syllabus\u27s incorporation of social and digital media helps students understand how collective minority groups use and interact with media as a political tool to challenge re-presentational regimes. More importantly, this syllabus employs real-world examples of popular culture that students engage in their everyday communication practices. This pedagogical approach challenges students to assess their online behaviors and understand the re-presentational impact of their work as future media and communication practitioners. Finally, this syllabus’s incorporation of vertical education practices demonstrates the evolutional intersections of past and current stereotypes associated with Black womanhood. Thus, this syllabus moves forward re-presentation instruction with an intersectional framework that helps instructors better understand how to appropriately implement intersectionality within the classroom