Toward an African Maritime Economy—Empowering the African Union to Revolutionize the African Maritime Sector

The maritime sector is the key to African prosperity; the continent’s leaders recognize this and have taken certain necessary steps. But it is time to pull these efforts together and move beyond policy papers and into strategy-based action aimed not at symptoms but core problems

A two-step approach to achieve secondary amide transamidation enabled by nickel catalysis.

A long-standing challenge in synthetic chemistry is the development of the transamidation reaction. This process, which involves the conversion of one amide to another, is typically plagued by unfavourable kinetic and thermodynamic factors. Although some advances have been made with regard to the transamidation of primary amide substrates, secondary amide transamidation has remained elusive. Here we present a simple two-step approach that allows for the elusive overall transformation to take place using non-precious metal catalysis. The methodology proceeds under exceptionally mild reaction conditions and is tolerant of amino-acid-derived nucleophiles. In addition to overcoming the classic problem of secondary amide transamidation, our studies expand the growing repertoire of new transformations mediated by base metal catalysis

Explosive Event in MON-3 Oxidizer System Resulting from Pressure Transducer Failure

In 2003, a Druck(Registered Trademark) pressure transducer failed catastrophically in a test system circulating nitrogen tetroxide at NASA Johnson Space Center White Sands Test Facility. The cause of the explosion was not immediately obvious since the wetted areas of the pressure transducer were constructed of materials compatible with nitrogen tetroxide. Chemical analysis of the resulting residue and a materials analysis of the diaphragm and its weld zones were used to determine the chain of events that led to the catastrophic failure. Due to excessive dynamic pressure loading in the test system, the diaphragm in the pressure transducer suffered cyclic failure and allowed the silicon oil located behind the isolation diaphragm to mix with the nitrogen tetroxide. The reaction between these two chemicals formed a combination of 2,4-di and 2,4,6-trinitrophenol, which are shock sensitive explosives that caused the failure of the pressure transducer. Further research indicated numerous manufacturers offer similar pressure transducers with silicone oil separated from the test fluid by a thin stainless steel isolation diaphragm. Caution must be exercised when purchasing a pressure transducer for a particular system to avoid costly failures and test system contamination

ARE ECONOMIC FUNDAMENTALS DRIVING FARMLAND VALUES?

Farmland, Land Value, Agricultural Finance, Land Economics/Use, Q14, Q15,

Corporate Brand Image: Antecedents, Mediating Role and Impact on Stakeholder Expectations

Corporate identity and image are shaped by the entirety of perceptions of a variety of stakeholders, both existing and potential ones, such as customers, suppliers, employees, general public, opinion makers, and government officials. Our study is an empirical investigation of corporate brand image and impact on one such stakeholder group made up of prospective employees. A large multinational, a technical and scientific research firm, a major recruiter of graduates from campuses of reputable universities across the nation was chosen as the subject. This paper develops and tests a path model of the antecedent factors affecting corporate brand image and specific expectations that stakeholders may have of a corporate brand. Based on a thorough literature review, a corporate brand image model that treated as antecedents the four constructs, awareness of organisation’s products, perceptions about culture, personality of the focal firm, and general expectations was proposed. Specific expectations that respondents may have about working with the firm was modeled to be influenced by the corporate brand image of the firm surveyed and also by the mentioned four antecedent constructs. The model is fitted to empirical data obtained from a national sample of 368 respondents using LISREL 8.5 methodology, and strong support was found for five, partial support for two of the nine hypotheses tested. Substantial evidence can be seen for the mediating role of corporate brand image in shaping specific expectations that stakeholders have from the corporate brand. Practical significance and managerial implications for marketing investments and organisational performance are detailed.

Lattice Monte Carlo calculations for unitary fermions in a finite box

We perform lattice Monte Carlo simulations for up to 66 unitary fermions in a finite box using a highly improved lattice action for nonrelativistic spin 1/2 fermions. We obtain a value of $0.366^{+0.016}_{-0.011}$ for the Bertsch parameter, defined as the energy of the unitary Fermi gas measured in units of the free gas energy in the thermodynamic limit. In addition, for up to four unitary fermions, we compute the spectrum of the lattice theory by exact diagonalization of the transfer matrix projected onto irreducible representations of the octahedral group for small to moderate size lattices, providing an independent check of our few-body simulation results. We compare our exact numerical and simulation results for the spectrum to benchmark studies of other research groups, as well as perform an extended analysis of our lattice action improvement scheme, including an analysis of the errors associated with higher partial waves and finite temporal discretization.Comment: Significant revisions from previous version. Included data at a larger volume and performed an infinite volume extrapolation of the Bertsch parameter. Published versio

Binary black hole merger dynamics and waveforms

We study dynamics and radiation generation in the last few orbits and merger of a binary black hole system, applying recently developed techniques for simulations of moving black holes. Our analysis of the gravitational radiation waveforms and dynamical black hole trajectories produces a consistent picture for a set of simulations with black holes beginning on circular-orbit trajectories at a variety of initial separations. We find profound agreement at the level of one percent among the simulations for the last orbit, merger and ringdown. We are confident that this part of our waveform result accurately represents the predictions from Einstein's General Relativity for the final burst of gravitational radiation resulting from the merger of an astrophysical system of equal-mass non-spinning black holes. The simulations result in a final black hole with spin parameter a/m=0.69. We also find good agreement at a level of roughly 10 percent for the radiation generated in the preceding few orbits.Comment: 11 pages, 11 figures, submitted to PRD, update citations, minor change