Single-ionization of helium at Ti:sapphire wavelengths: rates and scaling laws

We present a numerical and theoretical study of intense-field single-electron ionization of helium at 390 nm and 780 nm. Accurate ionization rates (over an intensity range of (0.175-34) X10^14 W/ cm^2 at 390 nm, and (0.275 - 14.4) X 10^14 W /cm^2 at 780 nm) are obtained from full-dimensionality integrations of the time-dependent helium-laser Schroedinger equation. We show that the power law of lowest order perturbation theory, modified with a ponderomotive-shifted ionization potential, is capable of modelling the ionization rates over an intensity range that extends up to two orders of magnitude higher than that applicable to perturbation theory alone. Writing the modified perturbation theory in terms of scaled wavelength and intensity variables, we obtain to first approximation a single ionization law for both the 390 nm and 780 nm cases. To model the data in the high intensity limit as well as in the low, a new function is introduced for the rate. This function has, in part, a resemblance to that derived from tunnelling theory but, importantly, retains the correct frequency-dependence and scaling behaviour derived from the perturbative-like models at lower intensities. Comparison with the predictions of classical ADK tunnelling theory confirms that ADK performs poorly in the frequency and intensity domain treated here.

The natural plasma testosterone profile of male blue tits during the breeding season and its relation to song output

In male birds, the gonadal hormone testosterone (T) is known to influence territorial and mating behaviour. Plasma levels of T show seasonal fluctuations which vary in relation to mating system and social instability. First, we determined the natural T profile of male blue tits Parus caeruleus during the breeding season. We found that plasma levels of T increased at the onset of nest building. Thus, the increase in circulating T was not associated with territory establishment, nor with the fertile period of the males' mates. In most individuals, T levels dropped to values close to zero during the period of chick feeding. Second, we investigated the relationship between plasma levels of T and male age, size, and singing behaviour. During the mating period, T levels did not differ between 1 yr old and older males and did not correlate with body size or condition. However, song output during the dawn chorus tended to be positively correlated with T levels. Therefore, if high T levels are costly, song output might be an honest indicator of male quality in blue tits. Finally, we show that plasma levels of T are significantly higher during the night than during the day. This pattern has also been observed in captive non-passerine birds, but its functional significance remains unknown.

Crystal and liquid crystalline polymorphism in 1-alkyl-3-methylimidazolium tetrachloropalladate(II) salts

1-Alkyl-3-methylimidazolium tetrachloropalladate(ii) salts ([C-n-mim](2)[PdCl4], n = 10, 12, 14, 16, 18) containing a single, linear alkyl-chain substituent on the cation have been synthesised and their behaviour characterised by differential scanning calorimetry, polarising optical microscopy and small-angle X-ray scattering. The salts display thermotropic polymorphism, exhibiting both crystal-crystal transitions and, for n = 14-18, the formation of a thermotropic smectic liquid crystalline phase.

Space and phase resolved optical emission in mode transitions of radio-frequency inductively coupled plasmas

Inductively coupled radio-frequency plasmas can be operated in two distinct modes. At low power and comparatively low plasma densities the plasma is sustained in capacitive mode (E-mode). As the plasma density increases a transition to inductive mode (H-mode) is observed. This transition region is of particular interest and governed by non-linear dynamics, which under certain conditions results in structure formation with strong spatial gradients in light emission. These modes show pronounced differences is various measureable quantities e.g. electron densities, electron energy distribution functions, ion energy distribution functions, dynamics of optical light emission. Here the transition from E- to H- mode in an oxygen containing inductively coupled plasma (ICP) is investigated using space and phase resolved optical emission spectroscopy (PROES). The emission, measured phase resolved, allows investigation of the electron dynamics within the rf cycle, important for understanding the power coupling and ionization mechanisms in the discharge. The temporal variation of the emission reflects the dynamics of relatively high-energy electrons. It is possible to distinguish between E- and H-mode from the intensity and temporal behaviour of the emission.

Consociationalism and its critics: Evidence from the historic Northern Ireland Assembly Election of 2007:

Critics of consociational power-sharing institutional arrangements in deeply divided societies argue that such arrangements solidify the underlying conflict cleavage and render it all-important for party competition and voter behaviour. I find evidence to the contrary in the case of voter behaviour at the historic 2007 Assembly election in Northern Ireland. At least in the unionist bloc, I find the effective disappearance of the ethno-national conflict cleavage as a determinant of voter choice. This suggests that consociational arrangements have led to both inclusion and moderation, rather than polarisation and ‘ethnic outbidding’

Healthcare professionals’ attitudes towards traumatic brain injury (TBI): The influence of profession, experience, aetiology and blame on prejudice towards survivors of brain injury

Primary objective: To investigate the attitudes of healthcare professionals towards individuals with traumatic brain injury (TBI) and their relationship to intended healthcare behaviour.

Research design: An independent groups design utilized four independent variables; aetiology, group, blame and gender to explore attitudes towards survivors of brain injury. The dependent variables were measured using the Prejudicial Evaluation and Social Interaction Scale (PESIS) and Helping Behaviour Scale (HBS).

Methods and procedures: A hypothetical vignette based methodology was used. Four hundred and sixty participants (131 trainee nurses, 94 qualified nurses, 174 trainee doctors, 61 qualified doctors) were randomly allocated to one of six possible conditions.

Main outcomes and results: Regardless of aetiology, if an individual is to blame for their injury, qualified healthcare professionals have more prejudicial attitudes than those entering the profession. There is a significant negative relationship between prejudice and helping behaviour for qualified healthcare professionals.

Conclusions: Increased prejudicial attitudes of qualified staff are related to a decrease in intended helping behaviour, which has the potential to impact negatively on an individual's recovery post-injury.

Influence of environmental enrichment on welfare-related behavioural and physiological parameters in growing pigs

Three hundred and twenty pigs were reared from birth to slaughter at 21 weeks in either barren or enriched environments. The barren environments were defined as intensive housing (slatted floors and minimum recommended space allowances) and the enriched environments incorporated extra space including an area which contained peat and straw in a rack. Behavioural observations showed that environmental enrichment reduced time spent inactive and rime spent involved in harmful social and aggressive behaviour (P

Service Innovation, Embeddedness and Business Performance: Evidence from Northern Ireland

This paper explores the factors that determine innovation by service firms, and in particular the contribution of intra- and extra-regional connectivity. Subsequently, it is examined how service firms' innovation activity relates to productivity and export behaviour. The empirical analysis is based on matched data from the 2005 UK Innovation Survey - the UK component of the 4th Community Innovation Survey (CIS) - and the Annual Business Inquiry for Northern Ireland. Evidence is found of negative intra-regional embeddedness effects, but there is a positive contribution to innovation from extra-regional connectivity, particularly links to customers. Relationships between innovation, exporting, and productivity prove complex, but suggest that innovation itself is not sufficient to generate productivity improvements. Only when innovation is combined with increased export activity are productivity gains evident.

Long-term return reversals-Value and growth or tax? UK evidence

This paper examines (i) whether value-growth characteristics have more power than past performance in predicting return reversals; and (ii) whether typical rational behaviour such as incentives to delay paying capital gain taxes can better explain long-term reversals than past performance. We find that value-growth characteristics generally provide better explanations for long-term stock returns than past performance. The evidence also shows that winners identified by capital gains dominate past performance winners in predicting reversals in the cross-sectional comparison. However, in the time-series analysis, when returns on capital gain winners are adjusted by the Fama and French (1996) risk factors, the predictive power of capital gain winners disappears. Our results show that capital gain winners are heavily featured as growth stocks. Return reversals in capital gain winners potentially reflect market price corrections for growth stocks. We conclude that investors’ incentives to delay paying capital gain taxes cannot fully rationalise long-term reversals in the UK market. Our results also imply that the long-term return pattern potentially reflects a mixture of investor rational and irrational behaviour.

Correlation Between the Electrical and Optical Properties of an Atmospheric Pressure Plasma During Siloxane Coating Deposition

The effect of varying process parameters on atmospheric plasma characteristics and properties of nanometre thick siloxane coatings is investigated in a reel-to-reel deposition process. Varying plasma operation modes were observed with increasing applied power for helium and helium/oxygen plasmas. The electrical and optical behaviour of the dielectric barrier discharge were determined from current/voltage, emission spectroscopy and time resolved light emission measurements. As applied power increased, multiple discharge events occurred, producing a uniform multi-peak pseudoglow discharge, resulting in an increase in the discharge gas temperature. The effects of different operating modes on coating oxidation and growth rates were examined by injecting hexamethyldisiloxane liquid precursor into the chamber under varying operating conditions. A quenching effect on the plasma was observed, causing a decrease in plasma input power and emission intensity. Siloxane coatings deposited in helium plasmas had a higher organic component and higher growth rates than those deposited in helium/oxygen plasmas.

Theoretical and experimental correlations of gas dissolution, diffusion, and thermodynamic properties in determination of gas permeability and selectivity in supported ionic liquid membranes

Supported ionic liquid membranes (SILMs) has the potential to be a new technological platform for gas/organic vapour separation because of the unique non-volatile nature and discriminating gas dissolution properties of room temperature ionic liquids (ILs). This work starts with an examination of gas dissolution and transport properties in bulk imidazulium cation based ionic liquids [C_nmim][NTf2] (n = 2.4, 6, 8.10) from simple gas H₂, N₂, to polar CO₂, and C₂H₆, leading to a further analysis of how gas dissolution and diffusion are influenced by molecular specific gas-SILMs interactions, reflected by differences in gas dissolution enthalpy and entropy. These effects were elucidated again during gas permeation studies by examining how changes in these properties and molecular specific interactions work together to cause deviations from conventional solution–diffusion theory and their impact on some remarkably contrasting gas perm-selectivity performance. The experimental perm-selectivity for all tested gases showed varied and contrasting deviation from the solution–diffusion, depending on specific gas-IL combinations. It transpires permeation for simpler non-polar gases (H₂, N₂) is diffusion controlled, but strong molecular specific gas-ILs interactions led to a different permeation and selectivity performance for C₂H₆ and CO₂. With exothermic dissolution enthalpy and large order disruptive entropy, C₂H₆ displayed the fastest permeation rate at increased gas phase pressure in spite of its smallest diffusivity among the tested gases. The C₂H₆ gas molecules “peg” on the side alkyl chain on the imidazulium cation at low concentration, and are well dispersed in the ionic liquids phase at high concentration. On the other hand strong CO₂-ILs affinity resulted in a more prolonged “residence time” for the gas molecule, typified by reversed CO₂/N₂ selectivity and slowest CO₂ transport despite CO₂ possess the highest solubility and comparable diffusivity in the ionic liquids. The unique transport and dissolution behaviour of CO₂ are further exploited by examining the residing state of CO₂ molecules in the ionic liquid phase, which leads to a hypothesis of a condensing and holding capacity of ILs towards CO₂, which provide an explanation to slower CO₂ transport through the SILMs. The pressure related exponential increase in permeations rate is also analysed which suggests a typical concentration dependent diffusion rate at high gas concentration under increased gas feed pressure. Finally the strong influence of discriminating and molecular specific gas-ILs interactions on gas perm-selectivity performance points to future specific design of ionic liquids for targeted gas separations.

MODELED DIFFUSION-CONTROLLED RESPONSE AND RECOVERY BEHAVIOR OF A NAKED OPTICAL FILM SENSOR WITH A HYPERBOLIC-TYPE RESPONSE TO ANALYTE CONCENTRATION

The diffusion-controlled response and recovery behaviour of a naked optical film sensor (i.e., with no protective membrane) with a hyperbolic-type response [i.e., S0/S = (1 + Kc), where S is the measured value of the absorbance or luminescence intensity of one form of the sensor dye in the presence of the analyte, S0 is the observed value of S in the absence of analyte and K is a constant] to changes in analyte concentration, c, in a system under test is approximated using a simple model, and described more accurately using a numerical model; in both models it is assumed that the system under test represents an infinite reservoir. Each model predicts the variations in the response and recovery times of such an optical sensor, as a function of the final external analyte concentration, the film thickness (I) and the analyte diffusion coefficient (D). From an observed signal versus time profile for a naked optical film sensor it is shown how values for K and D/I2 can be extracted using the numerical model. Both models provide a qualitative description of the often cited asymmetric nature of the response and recovery for hyperbolic-type response naked optical film sensors. It is envisaged that the models will help in the interpretation of the response and recovery behaviour exhibited by many naked optical film sensors and might be especially apposite when the analyte is a gas.

Information disclosure and depositor discipline in the Chinese banking sector

We investigate the relationship between information disclosure and depositor behaviour in the Chinese banking sector. Specifically, we enquire whether enhanced information disclosure enables investors to more effectively infer a banking institution's risk profile, thereby influencing their deposit decisions. Utilising an unbalanced panel, incorporating financial data from 169 Chinese banks over the 1998–2009 period, we employ generalised-method-of-moments (GMM) estimation procedures to control for potential endogeneity, unobserved heterogeneity, and persistence in the dependent variable. We uncover evidence that: (i) the growth rate of deposits is sensitive to bank fundamentals after controlling for macroeconomic factors, diversity in ownership structure, and government intervention; (ii) a bank publicly disclosing more transparent information in its financial reports, is more likely to experience growth in its deposit base; and (iii) banks characterised by high information transparency, well-capitalised and adopted international accounting standards, are more able to attract funds by offering higher interest rates.