Three-dimensional neuroelectronic interface for peripheral nerve stimulation and recording: realization steps and contacting technology

A three-dimensional array of microelectrodes for use in intraneural stimulation and recording is presented. The 128 electrodes are at the tips of silicon needles, which are electrically insulated from each other. The needles in the array have differing heights, resulting in a true three-dimensional electrode structure. The distance between the needles is 120 ¿m, while the heights are 600, 425 and 250 ¿m. An overview of the technology for the realization of the device is given, and the contacting of the array is discussed. The array is connected to a gate array (containing multiplexing electronics, current sources and buffer amplifiers) through controlled collapse chip connection

The break-up of continents and the formation of new ocean basins

Rifted continental margins are the product of stretching, thinning and ultimate break-up of a continental plate into smaller fragments, and the rocks lying beneath them store a record of this rifting process. Earth scientists can read this record by careful sampling and with remote geophysical techniques. These experimental studies have been complemented by theoretical analyses of continental extension and associated magmatism. Some rifted margins show evidence for extensive volcanic activity and uplift during rifting; at these margins, the record of the final stages of rifting is removed by erosion and obscured by the thick volcanic cover. Other margins were underwater throughout their formation and showed rather little volcanic activity; here the ongoing deposition of sediment provides a clearer record. During the last decade, vast areas of exhumed mantle rocks have been discovered at such margins between continental and oceanic crust. This observation conflicts with the well-established idea that the mantle melts to produce new crust when it is brought close to the Earth's surface. In contrast to the steeply dipping faults commonly seen in zones of extension within continental interiors, faults with very shallow dips play a key role in the deformation immediately preceding continental break-up. Future progress in the study of continental break-up will depend on studies of pairs of margins which were once joined and on the development of computer models which can handle rigorously the complex transition from distributed continental deformation to sea-floor spreading focused at a mid-ocean ridge

Development of a solderbump technique for contacting a three-dimensional multi electrode array

The application of a solder bump technique for contacting a multi electrode sensor/actuator system is presented. Techniques adapted from the literature could successfully be scaled down to 55×55 ¿m bumps at 120 ¿m heart-to-heart spacin

Explaining post-apartheid South African human rights foreign policy: unsettled identity and conflicting interests

The end of apartheid in 1994 brought with it many expectations – both domestically and internationally – about the kind of state the new South Africa would be and the foreign policies it would pursue, with many expecting South Africa to pursue a human rights-based foreign policy. However, South Africa has pursued a much more paradoxical foreign policy, with significant gaps between its stated commitment to human rights principles and its action in support of those principles. This article seeks to explain these gaps. Delving into the literature on norms-based and interest-based explanations of state behavior, it argues that both approaches help to explain South Africa’s foreign policy actions. However, it is the unsettled nature of its identities and interests after 1994, as its leaders (in particular Thabo Mbeki) sought to reconcile a commitment to democracy and human rights with equally strong (if not greater) commitments to Afrocentrism and anti-imperialism, which provides the most interesting avenues for exploration

Refrigerant and Oil Migration and Retention in Air Conditioning and Refrigeration Systems

Air Conditioning and Refrigeration Project 16

Sleep apnoea and its impact on public health

In 1997 we published a systematic review on the health effects of obstructive sleep apnoea and the effectiveness of treatment with CPAP. This generated much controversy and considerable correspondence. About half the letters received by the authors suggested that the paper was just stating the obvious, the other half that the paper was completely inaccurate. To help clarify our findings this paper will discuss the public health impact of sleep apnoea and the rationale behind systematic reviews

Z-related pairs in microtonal systems

Various infinite families of Z-related pairs in microtonal systems are presented. Soderberg's dual inversion is compared to a more special transformation, the one-pitch shift. The material is illustrated by several examples. \u

The microstructure of sediment-hosted hydrates: evidence from effective medium modelling of laboratory and borehole seismic data

Much of our knowledge of hydrate distribution in the subsurface comes frominterpretations of remote seismic measurements. A key step in such interpretations isan effective medium theory that relates the seismic properties of a given sediment toits hydrate content. A variety of such theories have been developed; these theoriesgenerally give similar results if the same assumptions are made about the extent towhich hydrate contributes to the load-bearing sediment frame. We have furtherdeveloped and modified one such theory, the self-consistentapproximation/differential effective medium approach, to incorporate additionalempirical parameters describing the extent to which both the sediment matrix material(clay or quartz) and the hydrate are load-bearing. We find that a single choice ofthese parameters allows us to match well both P and S wave velocity measurementsfrom both laboratory and in situ datasets, and that the inferred proportion of hydratethat is load-bearing varies approximately linearly with hydrate saturation. Thisproportion appears to decrease with increasing hydrate saturation for gas-richlaboratory environments, but increase with hydrate saturation when hydrate is formedfrom solution and for an in situ example