Relative partial photoionisation cross section (RPPICS) data have been obtained for a variety of transition metal compounds using synchrotron radiation in the incident photon energy range 17-115 eV. Cross section features such as p→d giant resonances, delayed maxima, Cooper minima and molecular shape resonances have been identified and interpreted in terms of the localisation properties of the ionising electrons. The RPPICS behaviour of the photoelectron (PE) band corresponding to ionisation of the 1a_1g highest occupied molecular orbital (HOMO) of [Moη-C₆H₅Me)₂] indicates that it is essentially metal-localised. The p→d giant resonant absorption enhancement of the cross section is found to be almost coincident in photon energy with a molecular shape resonance. Similar features in the 1e_2g^-1 and 1e_1g^-1 bands provide strong evidence for metal-ligand covalency in the associated MOs. In contrast, the monotonic fall off with increasing photon energy of the RPPICS of the 1e_1u^-1 band is typical of ligand-localised MOs. Studies of the closely related [Mη-C₇H₇)(η-C₅H₄R)] (M=Ti, Nb, Mo; R=H: M=Ta; R=Me) reveal a significant degree of both metal and ligand character to the 1e₂ MOs, suggesting that neither the +1 nor the -3 formalism for the charge on the cycloheptatrienyl ring in its complexes is a good one, as they imply a metal- and ligand-localised 1e₂ level respectively. Analysis of the occurrence and magnitude of shape resonances in all of these sandwich molecules suggests that they are governed chiefly by the amount of metal d orbital character in an MO. The 5e MOs of PF₃, traditionally regarded as fluorine 2p lone pair MOs, have been shown to possess significant phosphorus 3p atomic orbital (AO) character. Comparison of the data obtained on PF₃ with those on [Ni(PF₃)₄] indicates that the π back donation from the nickel 3d orbitals to the 7e lowest unoccupied MO of PF₃ also affects the composition of the 5e derived orbitals. A combined experimental and theoretical study has resulted in an assignment of the PE spectrum of OsO₄ in which an osmium np AO (n=5 and/or 6) derived spin-orbit splitting of the lower ionisation energy (IE) ²T₂ primary ion state is found. RPPICS results obtained on TiCl₄, TiBr₄ and ZrBr₄ indicate that their PE spectra may be interpreted within a framework in which the primary ion state ordering is preserved on moving from chloride to bromide and from first to second row transition metal. Bromine-centred spin-orbit coupling produces the more complicated spectra of TiBr₄ and ZrBr₄. In all cases, the highest IE band shows RPPICS behaviour which indicates that it arises from the 2a₁ MO, resolving the debate as to the assignment of the PE spectrum of TiCl₄. The He I and He II spectra of [(CH₃)ReO₃] have been measured and Extended Hückel MO calculations performed upon both this molecule and ReO₃Cl. A consistent assignment of their spectra has been achieved, based upon that of OsO₄, and it is found that the methyl group represents a much greater perturbation to tetrahedral symmetry than does a chlorine atom. The bonding between the metal and dithiolene fragments in [Fe₂(CO)₆S₂C₂(CF₃)₂] has been shown to be primarily due to an interaction between the b₁ symmetry Fe₂(CO)</sub>6</sub> HOMO and the n. MO of the dithiolene, which is doubly reduced. In [Ni(S,sub>2</sub>C₂(CF₃)₂)₂], however, the closer energy match of metal and ligand valence orbitals results in monoanionic dithiolene groups and a more complex PE spectrum.

The Weinberg-Salam model of the weak interaction predicts that any wavefunction contains a small admixture of functions of the opposite parity. As a result, radiative transitions which would have pure magnetic dipole (M1) character in the absence of weak parity mixing interactions acquire a small component of electric dipole (E1) character, implying that atoms will show weak optical activity in proportion to the ratio of the matrix elements R = E1/M1. This work describes a generalization of the MCDF procedure to include the weak interaction. This allows us to treat correlation, exchange, orthogonality and shielding in a consistent and rigorous manner. A pilot calculation on bismuth using a model potential highlighted numerical problems associated with the use of a uniform nuclear density distribution. Therefore we have used a Fermi distribution in the main calculations to avoid these difficulties. We give results for bismuth, thallium, lead and cesium; correlation (for the first three of these) and shielding (for all of these atoms) have been included by means of configuration interaction. We give the ratio R in both Coulomb (velocity) and Babushkin (length) gauges, and for bismuth, thallium and cesium a reasonable level of gauge invariance in the unshielded calculations was obtained, in contrast to other calculations.

<p> This research project focuses on estimating the effect of economic, demographic, and social factors in residential energy demand in Mexico from 2008 to 2014. Therefore, it estimates demand equations for electricity, natural gas, liquefied petroleum gas (LPG), coal and natural gas using Mexican household data from 2008 to 2014. It also applies accessibility theory and it estimates energy access indicators using different specifications of demand for LPG in 2014. Sprawl measures, gravity model, and central place theory are the accessibility theory supporting the energy access indicators. Results suggest the greater the household income, the population size, the educational level of the householder, the energy access, and the lower the energy price and the household size, the greater the demand for energy in Mexico from 2008 to 2014. The greater the education, the lower the demand for firewood and coal. LPG and firewood have a monopolistically competitive market structure. Energy access indicators informed by accessibility theory are statistically significant and show the expected sign when applied to LPG in Mexican household in 2014.</p><p>

The interest of this work is to explore the spin dependent effects of projectile structure in nuclear heavy ion induced reactions. The projectiles are considered to consist of two clusters which remain inert, the intercluster wavefunctions are obtained by the use of the orthogonality condition model. Excitation to the low lying projectile states is included by the use of coupled channels calculations. The projectile excited states are included by allowing excitation in the inter cluster wavefunctions. Coupling to the excited states is performed by multipole terms arising from a single folding model, which is used consistently throughout the work. The effects of projectile excitation are considered in two areas, elastic and inelastic scattering, and transfer reactions. It is found that the inclusion of the projectile excited states has a very strong effect on the spin dependent elastic observables, in particular the vector analysing powers. In contrast to earlier analysis it is found that projectile excitation plays a dominant role in reproducing the experimentally observed vector analysing powers for the elastic scattering of 6Li from 16O and 28Si at 22.8 MeV. Projectile excitation is also seen to produce strong spin dependent effects in the elastic scattering of Li from 120Sn at 44 MeV and of 19Ffrom 28Si at 60 MeV. The inclusion of projectile excitation via CCBA calculations produces changes in the transfer cross section for the 28Si (19F, 16O)31P(1/2+ ,g.s.) reaction. The observed changes can be understood in terms of the effects of spin dependence in the reaction path. The inclusion of projectile excitation however does not significantly improve the quality of the agreement with experimental data.

Potassium (K) is the main ash-forming element released from biomass during thermochemical conversion. A better understanding of K chemistry and monitoring of K species is needed to optimize combustion systems. Since K species are highly reactive and prevailing concentrations depend on the conversion conditions, accurate quantification requires in situ measurement techniques. Tunable diode laser absorption spectroscopy with a single-mode distributed feedback laser is used to probe the D1 transition of atomic potassium, K(g), at 769.9 nm. The large current tuning range of the diode laser (5 cm-1) enables monitoringthe wings of the absorption profile. Fitting to the acquired line shape wings is used as astrategy to enhance the dynamic range of the sensor and measure K(g) concentrations even under optically thick condition. A potassium-rich combustion environment is simulated by converting KOH salt in a premixed methane/air flat flame. Quantitative measurements of K(g) are made at 75 positions in the flame. This yields radial K(g) profiles at three different heightsin the plume above the KOH salt and an axial profile at the burner center. The acquired average K(g) concentrations are corrected for effective plume size, i.e. the absorption pathlength determined from the radial profiles. Knowledge of the K(g) distribution in flames can lead to a better understanding of K release and primary reaction kinetics.

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