Rubidium Polyhydrides Under Pressure: Emergence of the Linear H3- Anion

The structures of compressed rubidium polyhydrides, RbHn with n>1, and their evolution under pressure are studied using density functional theory calculations. These phases, which start to stabilize at only P=2 GPa, consist of Rb+ cations and one or more of the following species: H- anions, H2 molecules, and H3- units. The latter motif, the simplest example of a three-center four-electron bond, is found in the most stable structures, RbH5 and RbH3. Pressure induces the symmetrization of H3-. The thermodynamically most stable polyhydrides metallize above 200 GPa. At the highest pressures studied, our evolutionary searches find an RbH6 phase which contains polymeric (H3-)$_\infty$ chains that show signs of one-dimensional liquid-like behavior

An overview of very high level software design methods

Very High Level design methods emphasize automatic transfer of requirements to formal design specifications, and/or may concentrate on automatic transformation of formal design specifications that include some semantic information of the system into machine executable form. Very high level design methods range from general domain independent methods to approaches implementable for specific applications or domains. Applying AI techniques, abstract programming methods, domain heuristics, software engineering tools, library-based programming and other methods different approaches for higher level software design are being developed. Though one finds that a given approach does not always fall exactly in any specific class, this paper provides a classification for very high level design methods including examples for each class. These methods are analyzed and compared based on their basic approaches, strengths and feasibility for future expansion toward automatic development of software systems

Can Supersymmetry Naturally Explain the Positron Excess?

It has often been suggested that the cosmic positron excess observed by the HEAT experiment could be the consequence of supersymmetric dark matter annihilating in the galactic halo. Although it is well known that evenly distributed dark matter cannot account for the observed excess, if substantial amounts of local dark matter substructure are present, the positron flux would be enhanced, perhaps to the observed magnitude. In this paper, we attempt to identify the nature of the substructure required to match the HEAT data, including the location, size and density of any local dark matter clump(s). Additionally, we attempt to assess the probability of such substructure being present. We find that if the current density of neutralino dark matter is the result of thermal production, very unlikely ($\sim 10^{-4}$ or less) conditions must be present in local substructure to account for the observed excess.Comment: Version accepted by Physical Review

Defining a representative vibration durability test for electric vehicle (EV) rechargeable energy storage systems (RESS)

This study defines a process to devise random power spectral density (PSD) profiles that are representative of 100,000 miles of UK customer electric vehicle (EV) usage utilising vibration measurements from three contemporary EV’s, for undertaking vibration durability evaluations of underfloor mounted rechargeable energy storage systems (RESS). This paper also presents a critical assessment of current random vibration test procedures available to engineers for validating the mechanical performance of EV RESS via comparing the shock response spectrum (SRS) and fatigue damage spectrum (FDS) of these standards to the SRS and FDS of 100,000 miles UK durability

U.K. AND U.S. MULTINATIONAL CAPITAL BUDGETING AND FINANCING DECISIONS

The purpose of this study is to investigate the capital budgeting and financing decisions of UK and US multinational enterprises. Following a survey approach, this study examines the impact that the general equilibrium and the disequilibrium schools of reasoning have upon international investment and financing decisions of the multinational. Further, the degree of centralisation in financial policy is investigated in the light of the two schools of thought which partition corporate finance theory. A conjoint methodology is utilised in order to evaluate the gravity of various environmental issues upon the foreign direct investment decision as well as the utilities for discrete levels of those determinants. The research inquiry is enriched with in-depth interviews with fourteen senior finance managers of British based multinational companies

Optimal tensioning of nonlinear antenna structures

A new technique is described for optimizing the shape of a hoop/column antenna by adjusting the tensioning loads. The antenna structure is modelled using finite element procedures which include the geometric nonlinearities. The finite element equations constitute nonlinear equality constraints in the optimization problem. The new optimization technique solves this optimization problem without the introduction of either Lagrange multipliers or penalty functions. The results for two sample problems are presented in this dissertation

Bright Lines, Dark Deeds: Counting Convictions Under the Armed Career Criminal Act

The Armed Career Criminal Act of 1984 (ACCA) enables the federal government to help state authorities more effectively prosecute career criminals.\u27\u27 The ACCA imposes a mandatory sentence of at least fifteen years, and up to life imprisonment, for illegal possession of a firearm by anyone who has three prior convictions for violent felonies or serious drug offenses committed on occasions different from one another. To apply the ACCA, judges must determine first whether the defendant\u27s prior convictions meet the definitions of violent felony or serious drug offense, and secondly whether the offenses were committed on different occasions so that they count separately toward armed career criminal status. This Note focuses on the latter analysis - conviction counting