Evolution of the bursting-layer wave during a Type 1 X-ray burst

In a popular scenario due to Heyl, quasi periodic oscillations (QPOs) which are seen during type 1 X-ray bursts are produced by giant travelling waves in neutron-star oceans. Piro and Bildsten have proposed that during the burst cooling the wave in the bursting layer may convert into a deep crustal interface wave, which would cut off the visible QPOs. This cut-off would help explain the magnitude of the QPO frequency drift, which is otherwise overpredicted by a factor of several in Heyl's scenario. In this paper, we study the coupling between the bursting layer and the deep ocean. The coupling turns out to be weak and only a small fraction of the surface-wave energy gets transferred to that of the crustal-interface wave during the burst. Thus the crustal-interface wave plays no dynamical role during the burst, and no early QPO cut-off should occur.Comment: 8 pages, submitted to MNRA

A Game Theoretic Approach to Analyse Cooperation between Rural Households in Northern Nigeria

To improve the livelihood of the poor in Sub-Saharan Africa (SSA) much attention has been paid to the development of new agricultural technologies. We hypothesize that farmers can also improve their livelihood through cooperation. Partial cooperation, in which knowledge is shared or bargaining power improved, is relatively common in SSA, while cooperation where all resources are fully shared, which we address, has rarely been investigated. An important pre-requisite to establish such cooperation, is the need for a fair division rule for the gains of the cooperation. This paper combines linear programming and cooperative game theory to model the effects of cooperation of (individual) households on income and farm plans. Linear programming establishes insight in the optimal farm plans in cooperation, and cooperative game theory is used to generate fair division rules. The model is applied to a village in Northern Nigeria. Households are clustered based on socio-economic parameters, and we explore cooperation between clusters. Cooperation leads to increased income and results in changes in farm plans, because more efficient use of resources leads to more intensified agriculture (labour intensive – high value crops).Cooperations, Linear Programming, Nigeria, Livelihood, Agricultural and Food Policy, Community/Rural/Urban Development, Consumer/Household Economics, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, International Relations/Trade, Marketing, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,

An audio FIR-DAC in a BCD process for high power Class-D amplifiers

A 322 coefficient semi-digital FIR-DAC using a 1-bit PWM input signal was designed and implemented in a high voltage, audio power bipolar CMOS DMOS (BCD) process. This facilitates digital input signals for an analog class-D amplifier in BCD. The FIR-DAC performance depends on the ISI-resistant nature of this PWM-signal. An impulse response with only positive coefficients was chosen, because of its resistance to deadzone and mismatch. With a DAC current of 0.5 mA, the dynamic range is 111 dB (A-weighted), with SINAD = 103 dB (A-weighted). The current consumption is 1mA for the analog part and 4.8 mA for the digital part. The power consumption is 29 mW at V/sub dd/ = 5 V and the chip area is 2 mm/sup 2/ including the reference diode that can be shared by more channels

Asian development pathways and sustainable socio-technical regimes

Rapid industrialisation in Asia is generating a significant new demand for raw materials and pressure on local, regional and global environments. In the future these demands and pressures are expected to increase markedly. These concerns are models of development that assume that economic growth follows a pattern leading to a convergence between the structure, growth and productivity of economies over the long run. In these models, the structure of industries and sectors, technological capabilities and consumer preferences are regarded as converging towards patterns established in more advanced economies. By extension, convergence is also assumed to hold for the resource intensity and environmental pressure associated with growth in industrialising countries. This paper argues for greater attention to the resource and environmental quality of development. It argues that by applying ideas from an emerging literature on 'systems innovation' it becomes possible to envisage the emergence of new, more resource-efficient socio-technical systems as the basis of more sustainable development pathways in developing Asia. Such sustainable socio-technical systems will emerge in the context of interaction between domestic and globalised markets, knowledge flows and governance. Key issues for a research agenda are set out. © 2008 Elsevier Inc. All rights reserved

Are EMS environmentally effective? The link between environmental management systems and environmental performance in European companies

Based on the analysis of a large dataset on the environmental performance of European companies in five industrial sectors, this paper examines the question of whether the presence of an environmental management system (EMS) has a positive impact on the eco-efficiency of companies. It begins with a review of evidence about the link between EMS and environmental performance in business organisations, finding that, despite much research, there is still little quantitative evidence. The second part of the paper uses three independent statistical methods (simple correlations, Jaggi-Freedman indices and a 'trend differences' approach) to assess whether companies and production sites with EMS perform better than those without and whether performance improves after an EMS has been introduced. The paper shows that there is currently no evidence that EMS have a consistent and significant positive impact on environmental performance. Policy action based on the simple assumption that companies with an EMS perform better than those without therefore seems inappropriate