Self-mixing interference effects in tunable diode laser absorption spectroscopy

We report the effects of self-mixing interference on gas detection using tunable diode laser spectroscopy. For very weak feedback, the laser diode output intensity gains a sinusoidal modulation analogous to that caused by low finesse etalons in the optical path. Our experiments show that self-mixing interference can arise from both specular reflections (e.g. cell windows) and diffuse reflections (e.g. Spectralon™ and retroreflective tape), potentially in a wider range of circumstances than etalon-induced interference. The form and magnitude of the modulation is shown to agree with theory. We have quantified the effect of these spurious signals on methane detection using wavelength modulation spectroscopy and discuss the implications for real gas detecto

Integrating cavity based gas cells: a multibeam compensation scheme for pathlength variation

We present a four beam ratiometric setup for an integrating sphere based gas cell, which can correct for changes in pathlength due to sphere wall contamination. This allows for the gas absorption coefficient to be determined continuously without needing to recalibrate the setup. We demonstrate the technique experimentally, measuring methane gas at 1651nm. For example, contamination covering 1.2% of the sphere wall resulted in an uncompensated error in gas absorption coefficient of ≈41%. With the ratiometric scheme, this error was reduced to ≈2%. Potential limitations of the technique, due to subsequent deviations from mathematical assumptions are discussed, including severe sphere window contamination

Maximum Normalized Rate as a Flying Qualities Parameter

Discrete attitude commands have become a standard task for flying qualities evaluation and control system testing. Much pilot opinion data is now available for ground-based and in-flight simulations, but adequate performance measures and prediction methods have not been established. The Step Target Tracking Prediction method, introduced in 1978, correlated time-on-target and rms tracking data with NT-33 in-flight longitudinal simulations, but did not employ parameters easily measured in manned flight and simulation. Recent application of the Step Target Tracking Prediction method to lateral flying qualities analysis has led to a new measure of performance. This quantity, called Maximum Normalized Rate (MNR), reflects the greatest attitude rate a pilot can employ during a discrete maneuver without excessive overshoot and oscillation. MNR correlates NT-33 lateral pilot opinion ratings well, and is easily measured during flight test or simulation. Futhermore, the Step Target MNR method can be used to analyze large amplitude problems concerning rate limiting and nonlinear aerodynamics

Supersymmetric Higgs Singlet Effects on B-Meson FCNC Observables at Large tan(beta)

Higgs singlet superfields are usually present in most extensions of the Minimal Supersymmetric Standard Model (MSSM) that address the mu-problem, such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and the Minimal Nonminimal Supersymmetric Standard Model (MNSSM). Employing a gauge- and flavour-covariant effective Lagrangian formalism, we show how the singlet Higgs bosons of such theories can have significant contributions to B-meson flavour-changing neutral current (FCNC) observables for large values of $\tan\beta \stackrel{>}{{}_\sim} 50$ at the 1-loop level. Illustrative results are presented including effects on the B_s and B_d mass differences and on the rare decay $B_s\to\mu^+\mu^-$. In particular, we find that depending on the actual value of the lightest singlet pseudoscalar mass in the NMSSM, the branching ratio for $B_s\to\mu^+\mu^-$ can be enhanced or even suppressed with respect to the Standard Model prediction by more than one order of magnitude.Comment: 28 pages, 8 figures, LaTeX. Minor updates. Version to be published in PR

Gender, Part-time Employment and Employee Participation in the Workplace: Comparing Australia and the European Union

The international trend in the growth and incidence of 'no n-standard employment', and its highly gendered nature, is well documented. For ease of definition, and because of the nature of the available data, we focus upon part-time employment in this paper. Employee participation may be defined as any workplace process which 'allows employees to exert some influence over their work and the conditions under which they work' (Strauss 1998). It may be divided into two main approaches, direct participation and indirect or representative participation. Direct participation involves the employee in job or task-oriented decision-making in the production process at the shop or office floor level. Indirect or representative forms of participation include joint consultative committees, works councils, and employee members of boards of directors or management. In the EU context statutory works councils are the most common expression of representative participation, but in Australia, consultative committees resulting from union/employer agreement or unilateral management initiative are the more common form. All of these forms of employee participation raise important issues concerning part time employees. Effective participation has two further major requirements which also may disadvantage part timers. First, there is a ge neral consensus in the participation literature that training is required for effective direct or representative participation. Secondly, effective communication between management and employees is required for participation, preferably involving a two-way information flow. The issue is of further significance since it has decided gender implications. This paper seeks to redress this relative insularity in the literature by examining some broad trends in this area in Australia and the EU. It analyses survey data at a national level in Australia and compares with some survey data generated in the EU by the EPOC project and analysed by Juliet Webster along the lines which we suggest here. It tests the hypothesis that the growth of one non-standard form of employment, part-time employment, diminishes the access to participation in the workplace enjoyed by female workers in comparison with their male colleagues, and finds that the hypothesis is strongly confirmed. This has major implications for workplace equity, and for organisational efficiency.gender, part-time employment, employee participation, Australia, European Union

The Illawarra at Work: A Summary of the Major Findings of the Illawarra Regional Workplace Industrial Relations Survey

This paper summarises the main results of the Illawarra Regional Workplace Industrial Relations Survey (IRWIRS). The data is unique in that it provides the only comprehensive and statistically reliable source of information about workplace employee relations at the regional level in Australia, and compares regional patterns with national trends. The data collected relates to industrial relations indicators, workplace ownership, market conditions, management organisation and decision- making in the workplace, among other things. The results reveal a positive pattern of employment relations in the Illawarra, distinctive in many respects from national trends.Illawarra Regional Workplace Industrial Relations Survey, workplace employee relations, Australia

Modelling Basal Area of Perennial Grasses in Australian Semi-Arid Wooded Grasslands

In many semi-arid pastoral systems, landscape processes easily become dysfunctional. Shifts to less functional states may be irreversible, and have long-term consequences for pastoral profitability and social viability of rural communities. Typically, shifts to lower functional states involve a decline in perennial grasses (Hodgkinson, 1994). Here we develop a conceptual basis for modelling the basal area of perennial grasses in a semi-arid grassland and validate the model using data from a 10-year grazing study

Technology Adoption Factors in the Digitization of Popular Culture: Analyzing the Online Gambling Market

This study explores the psychological factors that influence market diffusion of popular culture digital services. Digital service websites have been diffusing through global markets with relative ease, but the factors influencing this are not well understood. The transition from the brick and mortar services to a digital outlet represents a form of market disruption but the way that this impacts the consumer experience and the way firms engage in innovation are not fully understood, nor are the various cognitive factors driving the adoption rates. There is a need to understand cognitions that influence intent to engage, as well as the perceptions of the social environment in which the service offering occurs. Therefore, we offer an examination of different social contexts (US and UK) to explore the impact of certain attitudes and norms toward online gambling consumption. The results of study demonstrate how variations between online and offline environments impact consumer adoption and market diffusion. Additionally, the results further support the need for more studies to focus on the soft factors that influence their innovation capabilities