Thurston's metric on Teichm\"uller space and the translation lengths of mapping classes

We show that the Teichm\"uller space of a surface without boundary and with punctures, equipped with Thurston's metric is the limit (in an appropriate sense) of Teichm\"uller spaces of surfaces with boundary, equipped with their arc metrics, when the boundary lengths tend to zero. We use this to obtain a result on the translation distances for mapping classes for their actions on Teichm\"uller spaces equipped with their arc metrics

Mechanisms of Auger-induced chemistry derived from wave packet dynamics

To understand how core ionization and subsequent Auger decay lead to bond breaking in large systems, we simulate the wave packet dynamics of electrons in the hydrogenated diamond nanoparticle C_(197)H_(112). We find that surface core ionizations cause emission of carbon fragments and protons through a direct Auger mechanism, whereas deeper core ionizations cause hydrides to be emitted from the surface via remote heating, consistent with results from photon-stimulated desorption experiments [Hoffman A, Laikhtman A, (2006) J Phys Condens Mater 18:S1517–S1546]. This demonstrates that it is feasible to study the chemistry of highly excited large-scale systems using simulation and analysis tools comparable in simplicity to those used for classical molecular dynamics

The definition of "Insider" in section 3 of the securities markets Act 1988: A review and comparison with other jurisdictions

Statutory definitions of what constitutes an “insider” for the purposes of insider trading laws may be based on either a “person connection” approach or an “information connection” approach. The “person connection” approach defines “insider” by reference to the relationship of the person to the public issuer of securities, while the “information connection” approach considers anyone who has material price-sensitive information about the issuer to be an insider, regardless of his or her relationship to the issuer. In common with Japan, Hong Kong and China, New Zealand’s insider trading law — the Securities Markets Act 1988 — uses a person connection approach in its definition of “insider”. Other jurisdictions, however, including both the United Kingdom and Australia, have, to varying degrees, recently amended their definitions to reflect the information connection approach. The United States, although the first country to address the issue of insider trading, lacks a statutory definition of “insider” and instead relies on generally applicable laws against securities fraud. It has developed a definition with elements of both approaches. This paper reviews the definitions in use in the United States and in other countries (including New Zealand) which have been influenced by the American experience. It concludes that the narrow, relationship-based approach does not capture some conduct that may be damaging to the integrity of the securities market. A definition based on the information connection approach (perhaps combined with elements of the person connection approach) may therefore be preferable to New Zealand’s current definition

The Thermal Degradation of Nanocomposites That Contain an Oligomeric Ammonium Cation on the Clay

The thermal degradation of polystyrene, high-impact polystyrene, ABS terpolymer, poly(methyl methacrylate), polypropylene and polyethylene nanocomposites has been studied using thermogravimetric analysis coupled to Fourier transform infrared spectroscopy, TGA/FT-IR. The nanocomposites that have been studied include immiscible, intercalated and exfoliated systems and the evolved gases do not depend upon the type of nanocomposite and are qualitatively similar to those of the virgin polymer. In the case of the styrenics, the presence of clay promotes the production of oligomer, rather than monomer. It is suggested that this change in evolved products may offer an explanation for why some polymers give large reduction in peak heat release rates while others give much smaller reductions. According to this notion, any polymer that undergoes degradation to produce both oligomer and monomer should give a large reduction in peak heat release rate

Coexistence of strong nematic and superconducting correlations in a two-dimensional Hubbard model

Using a dynamic cluster quantum Monte Carlo approximation, we study a two-dimensional Hubbard model with a small orthorhombic distortion in the nearest neighbor hopping integrals. We find a large nematic response in the low-frequency single-particle scattering rate which develops with decreasing temperature and doping as the pseudogap region is entered. At the same time, the d-wave superconducting gap function develops an s-wave component and its amplitude becomes anisotropic. The strength of the pairing correlations, however, is found to be unaffected by the strong anisotropy, indicating that d-wave superconductivity can coexist with strong nematicity in the system.Comment: 4 pages, 4 figures, published as PRB 84, 220506(R) (2011

Life cycle assessment of Libyan crude oil

Petroleum products such as petrol and diesel are fossil fuels and have a high environmental impact. There is a demand to minimize these impacts especially in the upstream and midstream oil operations, i.e. exploration, production and refining processes, due to current and upcoming environmental regulations/policies and increased environmental consumer awareness. Thus, integration of the tools, methods and techniques for sustainability into products is becoming essential to comply with environmental regulations. The Libyan petroleum industry appears to be very slow in approaching modern concepts of approaches of sustainability including Life Cycle Assessment and studies. Therefore, this paper presents a novel environmental Life Cycle assessment of Libyan petroleum refining processes conducted with the support of Life Cycle Assessment methods and related tools including Software SimaPro. The refining processes from the Azzawya Oil refinery, are analyzed and used in the assessment and the data for the assessments was collected through fieldwork conducted in Feb 2013 in both El-Sharara oil field (Repsol Oil Company) and Azzawya Oil refinery in Libya. The results show that the first significant environmental impacts are associated with fossil fuels and the second major impacts are the respiratory inorganic impacts

Formulating Weak Lensing from the Boltzmann Equation and Application to Lens-lens Couplings

The Planck mission has conclusively detected lensing of the Cosmic Microwave Background (CMB) radiation from foreground sources to an overall significance of greater than $25\sigma$. The high precision of this measurement motivates the development of a more complete formulation of the calculation of this effect. While most effects on the CMB anisotropies are widely studied through direct solutions of the Boltzmann equation, the non-linear effect of CMB lensing is formulated through the solutions of the geodesic equation. In this paper, we present a new formalism to the calculation of the lensing effect by \emph{directly solving the Boltzmann equation}, as we did in the calculation of the CMB anisotropies at recombination. In particular, we developed a diagrammatic approach to efficiently keep track of all the interaction terms and calculate all possible non-trivial correlations to arbitrary high orders. Using this formalism, we explicitly articulate the approximations required to recover the usual remapping approach used in current studies of the weak lensing. In addition, we point out additional unexplored corrections that are manifest in our formalism to which experiments may be sensitive. As an example, we calculate the correction to the CMB temperature power spectrum for the \emph{lens-lens} coupling effects which are neglected in standard calculations. We find that the correction is $\lesssim 0.1\%$ of the CMB temperature power spectrum for $\ell$ up to 3000 and thus is comparable to the cosmic variance.Comment: 25 pages, 3 figures, 4 tables, CMB, lensin

Spin-charge Separation in Nodal Antiferromagnetic Insulator

In this paper, by using two dimensional (2D) Hubbard models with pi-flux phase and that on a hexagonal lattice as examples, we explore spin-charge-separated solitons in nodal antiferromagnetic (AF) insulator - an AF order with massive Dirac fermionic excitations (see detail in the paper). We calculate fermion zero modes and induced quantum numbers on solitons (half skyrmions) in the continuum limit, which are similar to that in the quasi one-dimensional conductor polyacetylene (CH)x and that in topological band insulator. In particular, we find some novel phenomena : thanks to an induced staggered spin moment, a mobile half skyrmion becomes a fermionic particle; when a hole or an electron is added, the half skyrmion turns into a bosonic particle with charge degree of freedom only. Our results imply that nontrivial induced quantum number on solitons may be a universal feature of spin-charge separation in different systems