Theory of strongly correlated electron systems. II. Including correlation effects into electronic structure calculations

We have previously shown that a division of the f-shell into two subsystems gives a better understanding of the cohesive properties as well the general behavior of lanthanide systems. In this article, we present numerical computations, using the suggested method. We show that the picture is consistent with most experimental data, e.g., the equilibrium volume and electronic structure in general. Compared with standard energy band calculations and calculations based on the self-interaction correction and LIDA + U, the f-(non-f)-mixing interaction is decreased by spectral weights of the many-body states of the f-ion. (c) 2005 Wiley Periodicals, Inc.

Chemical and structural disorder in eumelanins: A possible explanation for broadband absorbance

We report the results of an experimental and theoretical study of the electronic and structural properties of a key eumelanin precursor-5,6,-dihydroxyindole-2-carboxylic acid ( DHICA) - and its dimeric forms. We have used optical spectroscopy to follow the oxidative polymerization of DHICA to eumelanin and observe red shifting and broadening of the absorption spectrum as the reaction proceeds. First principles density functional theory calculations indicate that DHICA oligomers ( possible reaction products of oxidative polymerization) have the gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital red-shifted gaps with respect to the monomer. Furthermore, different bonding configurations ( leading to oligomers with different structures) produce a range of gaps. These experimental and theoretical results lend support to the chemical disorder model where the broadband monotonic absorption characteristic of all melanins is a consequence of the superposition of a large number of nonhomogeneously broadened Gaussian transitions associated with each of the components of a melanin ensemble. These results suggest that the traditional model of eumelanin as an amorphous organic semiconductor is not required to explain its optical properties and should be thoroughly reexamined. These results have significant implications for our understanding of the physics, chemistry, and biological function of these important biological macromolecules. Indeed, one may speculate that the robust functionality of melanins in vitro is a direct consequence of its heterogeneity, i.e., chemical disorder is a "low cost" natural resource in these systems

Structural change in macroeconomic time series: A complex systems perspective

We demonstrate that the process of generating smooth transitions Call be viewed as a natural result of the filtering operations implied in the generation of discrete-time series observations from the sampling of data from an underlying continuous time process that has undergone a process of structural change. In order to focus discussion, we utilize the problem of estimating the location of abrupt shifts in some simple time series models. This approach will permit its to address salient issues relating to distortions induced by the inherent aggregation associated with discrete-time sampling of continuous time processes experiencing structural change, We also address the issue of how time irreversible structures may be generated within the smooth transition processes. (c) 2005 Elsevier Inc. All rights reserved.

A green stick or a fresh stick?: Locating customary penalties in the post-colonial era

Former colonies and dependencies in the South Pacific do not have the luxury of entirely ‘homegrown’ laws. Their legal systems are burdened with a ‘legacy’ of transplanted laws, developed for use in a foreign country, imposed on pre-existing systems of custom and culture. As a result, many small island countries are struggling to balance the demands of law from different sources, designed to operate in fundamentally different circumstances. In addition to the conflict that occurs in areas of substantive law, where customary and introduced law may prescribe a different rule for the same situation, the two systems differ in their approach to procedure, penalties and relief. This paper considers the divide between the theory and practice of introduced law and customary law and examines the way in which conflicts have been dealt with by the courts. In particular, it uses the example of banishment to illustrate the type of problems that arise in a plural system. The paper looks at the balancing exercise which has been necessary when custom, in the form of banishment, comes into conflict with introduced law, in the form of constitutional rights.

Career research in a post-modern era

In recent years, career theory and practice has been challenged to revise and reinvigorate itself in order to remain relevant in the post- modern world. The most fundamental challenge is to produce an identity for career practice that is congruent with the post-modern world. Career research is facing a similar challenge as it has been dominated by methodologies that emanate out of the positivist worldview of the modern era and has been mainly quantitative in nature. In their recent research, the authors have been examining methodologies that accommodate the tenets of the post-modern world – post-modernism, constructivism and career psychology. This article overviews post- modern considerations by exploring the possibilities offered by the Systems Theory Framework of career development and the 'My System of Career Influence' reflection activity as research tools. Examples of recent research are briefly described.

Actor-network theory as a theoretical lens and research strategy for investigating firm internationalisation

Totally generalisable theories of firm internationalisation in the post-industrial era of international business, where national barriers are becoming less significant and technology becoming more influential, appear to be illusory. Stepwise or evolutionary models that predict gradual internationalisation are under challenge from empirical evidence of rapid internationalisation such as the phenomenon of the “born global” firm. Similarly, equilibrium models such as the eclectic paradigm have been criticised for being static and unable to account for process and path dependency. In this paper, the information and knowledge assumptions implied in theories of firm internationalisation are outlined and discussed. From this discussion, we suggest that actor-network theory, with its balance between description and explanation, may be a useful theoretical and empirical tool for investigating the complex and heterogeneous process of firm internationalisation whilst creating opportunities for further theory building.

Comparisons of the structural and catalytic properties of Ti-HMS synthesized using the hydrothermal and molecular designed dispersion methods

Titanium containing wormhole-like mesoporous silicas, denoted Ti-HMS, synthesized both via the hydrothermal synthesis route and the post synthesis grafting technique, known as molecular designed dispersion, have been successfully applied in the gas phase oxidation of Toluene to CO and CO2. Selectivity towards CO2 for all catalysts, at temperatures between 400-600degreesC, was above 80%. Benzene and benzaldehyde were observed at temperatures above 450degreesC, but in very low concentrations. The conversion of toluene was shown to increase significantly when the V-TEX/N-MESO ratios were increased from 0.07 to 0.84. No significant difference in catalytic activity was observed for catalysts prepared via the different synthesis techniques. The catalytic activity also depends on the concentration of tetrahedrally coordinated titanium atoms and not on the total concentration of titanium in the catalyst.

Post-Bretton Woods evidence on PPP under different exchange rate regimes

This article investigates the behaviour of exchange rates across different regimes for a post-Bretton Woods period. The exchange rate regime classification is based on the classification of Frankel et al. (2004) who condensed the 10 categories of exchange rate regimes reported by the International Monetary Fund (IMF) into three categories. Panel unitroot tests and panel cointegration are used to examine the Purchasing Power Parity (PPP) hypothesis. The latter test is used to check for both the weak and strong forms of PPP. The panel unit-root tests show no evidence of PPP and suggest there is no difference in the behaviour of exchange rates across different regimes. However, failure to detect PPP across any of the regimes could be due to structural breaks. This assumption is reinforced by the results of cointegration tests, which suggest that there exists at least a weak form of PPP for the different regimes. The evidence for strong PPP decreases as the exchange rate regime moves away from a flexible exchange rate regime.

Enterprise resource planning and the post bureaucratic organization:'formalization' as trust in the system versus 'solidarity' as trust in individuals

Purpose – The purpose of the paper is to use a case study setting involving the implementation of an enterprise resource planning (ERP) system to expose and analyze the conflicts in the characterizations of the post bureaucratic organisation (PBO) in the literature. ERP implementations are often accompanied by increasing levels of stress in organizations that place pressures on organizational relationships and structures. Additionally, ERPs are regarded as introducing their own techno-logic of centralization, standardization and formalization that provides an apparent contrast to the exhortations about employee empowerment. Design/methodology/approach – A case study of ERP implementation in a medium-sized entity is presented. The paper explores aspects of ERP and PBO from the context of postmodern organization theory. Findings – Some concerns about PBO identified in the literature are reflected in the case situation. For example, there is a commitment to give up private time and work flexibly by some employees. The paper also provides evidence of the way the management team substitute their reliance on a key individual knowledge worker for that of an ERP system and external vendor support. Paradoxically, trust in that same knowledge worker and between core users of the system is essential to enable the implementation of the system. Originality/value – This paper adds empirical insight to a predominantly theoretical literature. The case evidence indicates some conflicting implications in the concurrent adoption of PBO and ERP.

Corruption in the post-Soviet workplace: the experiences of recent graduates in contemporary Ukraine

While Ukraine was bestowed market economy status by the European Union in 2005 its labour market still endures many structural problems. By exploring the experiences of young graduate employees this article highlights the difficultly in obtaining work within Ukraine's labour market and the problems they face once they have secured employment. Rather than seeing the development of a transparent labour market the collapse of the command economy has seen a relatively closed system develop. The article demonstrates how many jobs are secured through the use of connections or the demanding, and payment, of bribes.The situation does not improve once graduates obtain long-term employment. Interviewees discuss the lack of job security, the informal payment of wages and the lack of legal protection from corrupt employer practices. The article has broader resonance outside of the Ukrainian case study as the discussion of workplace corruption highlights how the issue is concerned with much more than simply cash based transactions and how those that endure it are likely to turn to the informal economy for employment.

Structural change in apartheid era South Africa:1975-93

This paper examines the sources of structural changes in output growth of South Africa's economy over 1975-93 using a decomposition method within the inputoutput (IO) framework for analysing output changes from a demand side perspective. It decomposes output growth into private consumption, government consumption, investment and export components and also measures the impact of import substitution and changes in intermediate input use (as indicated by changes in IO coefficients). It is found that, before 1981, overall output growth was multi-components driven with all the above components contributing positively to economic growth. However, the collapse of investment demand is by far the single largest factor contributing to the economic stagnation that categorizes the post-1981 period.

Employment outcomes and plant closure in a post-industrial city:an analysis of the labour market studies of MG Rover workers three years on

This paper examines how the loss of 6300 jobs from the closure of MG Rover (MGR) in the city of Birmingham (UK) in April 2005 affected the employment trajectories of ex-workers, in the context of wider structural change and efforts at urban renewal. The paper presents an analysis of a longitudinal survey of 300 ex-MGR workers, and examines to what extent the state of local labour markets and workers’ geographical mobility—as well as the effectiveness of the immediate policy response and longer-term local economic strategies—may have helped to balance the impacts of personal attributes associated with workers’ employability and their reabsorption into the labour markets. It is found that the relative buoyancy of the local economy, the success of longer-run efforts at diversification and a strong policy response and retraining initiative helped many disadvantaged workers to find new jobs in the medium term. However, the paper also highlights the unequal employment outcomes and trajectories that many lesser-skilled workers faced. It explores the policy issues arising from such closures and their aftermath, such as the need to co-ordinate responses, to retain institutional capacity, to offer high-quality training and education resources to workers and, where possible, to slow down such closure processes to enable skills to be retained and reused within the local economy.

Higher education reform in Kyrgyzstan: the politics of neoliberal agendas in theory and practice

There would seem to be no greater field for observing the effects of neo-liberal reforms in higher education than the former Soviet university, where attempts to legitimize neo-liberal philosophy over Soviet ideology plays out in everyday practices of educational reform. However, ethnographic research about higher education in post-Soviet Central Asia suggests that its “liberalization” is both an ideological myth and a complicated reality. This chapter focuses on how and why neo-liberal agendas have “travelled” to the Central Asian republic of Kyrgyzstan, what happens when educators encounter and resist them, and why these spaces of resistance are important starting points for the development of alternative visions of educational possibility in this recently “Third-worlded” society.