Diffusion Monte Carlo study of the equation of state of solid ortho-D2_2

We present results of Diffusion Monte Carlo calculations for a system of solid ortho-D_2 at different densities, for pressure ranging from 0 up to 350MPa. We compare the equation of state obtained using two of the most used effective intermolecular potentials, i.e. the Silvera--Goldman and the Buck potentials, with experimental data, in order to assess the validity of the model interactions. The Silvera-Goldman potential has been found to provide a satisfactory agreement with experimental results, showing that, as opposed to what recently found for p-H_2, three--body forces can be efficiently accounted for by an effective two--body term.Comment: 11 pages, 4 figure

Enterprise Risk Management at Top Agro Inc.

Top Agro (TA - not its real name) is a small crop protection start-up operating in the European Union. In a relatively short period of time TA has been able to secure a reasonable profit margin and build a solid niche in the Italian crop protection market. The driving force in their success is the professional expertise of the two owners, their knowledge of the domestic market, and the highly flexible business model they’ve developed. Chemicals are sourced either in the Far East via a Hong Kong based commercial partner or purchased directly from other European domestic suppliers. TA is responsible for the formulation and packaging of the finished product, which is then distributed in the domestic Italian market. Although TA is now profitable, further sales growth is unlikely. One of the owners is convinced that significant benefits may be obtained by identifying and controlling the key risks that TA is exposed to, in particular by reducing the price risk in their international supply chain. This case has been classroom tested at the senior undergraduate and MBA level with good results. It works well as opening case for an eMBA course on managing price risk, as it provides an opportunity to map the risk “opportunity set†via the ERM challenging students to reason and set intervention priorities by focusing on currency exchange rates and risk management as the most immediate and promising action.supply chain, enterprise risk management, currency risk management, crop protection., Crop Production/Industries, Demand and Price Analysis, Productivity Analysis, Risk and Uncertainty,

Veggies 4U's Energy Pricing Dilemma

Veggies 4U is a young and dynamic family-run greenhouse: Lucy and her husband run the business with the help of a small group of friends and colleagues who serve on the company's Board of Directors. Lucy is preparing a report to the Board to recommend a natural gas supply contract for the next three years. The company has received four different contract offers, ranging from a simple forward contract, to a maximum cost contract with a price floor. The case focuses on the pricing and risk management opportunities offered by an integrated North American natural gas market. Lucy has to assess the different supply contract offers received by the company and to reverse engineer them in order to benchmark their cost with that of potential synthetic alternatives Veggies 4U could build. Once Lucy has decided what to recommend, she has to sell it to the Board.Energy price risk, Natural gas supply contract, Financial engineering, Risk, Demand and Price Analysis, Risk and Uncertainty,

Does a prestellar core always become protostellar? Tracing the evolution of cores from the prestellar to protostellar phase

Recently, a subset of starless cores whose thermal Jeans mass is apparently overwhelmed by the mass of the core has been identified, e.g., the core {\small L183}. In literature, massive cores such as this one are often referred to as "super-Jeans cores". As starless cores are perhaps on the cusp of forming stars, a study of their dynamics will improve our understanding of the transition from the prestellar to the protostellar phase. In the present work we use non-magnetic polytropes belonging originally to the family of the Isothermal sphere. For the purpose, perturbations were applied to individual polytropes, first by replacing the isothermal gas with a gas that was cold near the centre of the polytrope and relatively warm in the outer regions, and second, through a slight compression of the polytrope by raising the external confining pressure. Using this latter configuration we identify thermodynamic conditions under which a core is likely to remain starless. In fact, we also argue that the attribute "super-Jeans" is subjective and that these cores do not formally violate the Jeans stability criterion. On the basis of our test results we suggest that gas temperature in a star-forming cloud is crucial towards the formation and evolution of a core. Simulations in this work were performed using the particle-based Smoothed Particle Hydrodynamics algorithm. However, to establish numerical convergence of the results we suggest similar tests with a grid-scheme, such as the Adaptive mesh refinement.Comment: 14 pages, 24 figures and 1 table; To appear in Monthly Notices of the Royal Astronomical Societ

The Iraq War: killing dreams of a unified EU?

For students of EU public policy, the EU's reaction during and after the Iraq War may represent the same story of impotence that has historically plagued the EU when trying to speak with a single voice and act with a united front during a major world crisis. Despite some achievements with the EU's Common and Foreign Security Policy (CFSP) of the early 1990s (Ginsberg 1997; Holland 1995), the Iraq War perhaps best reflects Cameron's concerns: "in handling serious political crises, especially those involving armed conflict, the Union has rarely acted as one", or acted effectively (Cameron, 1998, 66). Seeking to better understand why the EU did not act effectively during the Iraq War and to consider what lessons can be taken from this experience, the paper has three main objectives. First, the paper considers the theoretical reasons that help explain why the EU has historically failed to create a common defence and security policy. The section thereafter analyses developments during the Iraq war and tests which theoretical explanations (or combinations thereof) are of most value to understand the EU's stance. The final section then considers the future of the EU as an international actor in light of the fundamental concepts introduced by Hill (1993) regarding 'capabilities' and 'expectations' of EU foreign policy

Capital Taxation and Electoral Accountability

In a representative democracy, voters can use elections to protect their property by holding politicians accountable for the tax policies they implement while in office. This paper demonstrates that performance voting can - partly or wholly - solve the capital levy problem. We characterise the �best� non-expropriating tax policies that can be sustained in a stationary Markov Perfect Equilibrium; show when this coincides with the second best tax policy; and discuss, in detail, the robustness of the result

Coherent scattering of a Multiphoton Quantum Superposition by a Mirror-BEC

We present the proposition of an experiment in which the multiphoton quantum superposition consisting of N= 10^5 particles generated by a quantum-injected optical parametric amplifier (QI-OPA), seeded by a single-photon belonging to an EPR entangled pair, is made to interact with a Mirror-BEC shaped as a Bragg interference structure. The overall process will realize a Macroscopic Quantum Superposition (MQS) involving a microscopic single-photon state of polarization entangled with the coherent macroscopic transfer of momentum to the BEC structure, acting in space-like separated distant places.Comment: 4 pages, 4 figure

Comment to "Packing Hyperspheres in High-Dimensional Euclidean Space"

It is shown that the numerical data in cond-mat/0608362 are in very good agreement with the predictions of cond-mat/0601573.Comment: comment to cond-mat/0608362; 3 pages, 1 figur

Effects of the network structural properties on its controllability

In a recent paper, it has been suggested that the controllability of a diffusively coupled complex network, subject to localized feedback loops at some of its vertices, can be assessed by means of a Master Stability Function approach, where the network controllability is defined in terms of the spectral properties of an appropriate Laplacian matrix. Following that approach, a comparison study is reported here among different network topologies in terms of their controllability. The effects of heterogeneity in the degree distribution, as well as of degree correlation and community structure, are discussed.Comment: Also available online at: http://link.aip.org/link/?CHA/17/03310