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Superconducting spintronics has emerged in the past decade as a promising new field that seeks to open a new dimension for nanoelectronics by utilizing the internal spin structure of the superconducting Cooper pair as a new degree of freedom. Its basic building blocks are spin-triplet Cooper pairs with equally aligned spins, which are promoted by proximity of a conventional superconductor to a ferromagnetic material with inhomogeneous macroscopic magnetization. Using low-energy muon spin-rotation experiments we find an unanticipated effect, in contradiction with the existing theoretical models of superconductivity and ferromagnetism: the appearance of a magnetization in a thin layer of a non-magnetic metal (gold), separated from a ferromagnetic double layer by a 50-nm-thick superconducting layer of Nb. The effect can be controlled either by temperature or by using a magnetic field to control the state of the remote ferromagnetic elements, and may act as a basic building block for a new generation of quantum interference devices based on the spin of a Cooper pair.

Josephson junction oscillators provide a means to determine the dielectric constant (?R) and its frequency, temperature and electric field dependence (?R(?,T,E)) in thin-film dielectrics in the frequency range 100-900 GHz. Here, we have applied this technique to a 150 nm thick SrTiO3(STO) film and found a variation in ?Rat 4.2 K from 363 ± 5 at one end of the sample to 150 ± 6 at the other end and in the absence of external bias voltage Vacross the STO. On application of such a bias, the ?Rof the film at 4.2 K was found to change by 30%. The maximum in ?R(V) was found to be at ?1 V instead of the expected 0 V, indicating the presence of an internal electric field in the STO layer, which we attribute to the difference in work functions of the gold and YBa2Cu3O7electrodes in our structure. ?R(T) was markedly different to that of bulk STO. In our thin film, ?R(T) has a broad shoulder in which the temperature dependence is small between about 35 and 50 K, above which it rises again.

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We have recently developed a technique for fabricating SNS junctions in MgB₂ thin films using a focused ion beam. These junctions show a strong modulation of the critical current by applied magnetic field and microwaves. They also show large I_cR_N products in excess of 1 mV at 4.2 K making them attractive candidates for a range of superconducting electronics applications. We have made SQUIDs with directly coupled pick-up loops using this technique which show large voltage modulations (175 μV at 10 K) and noise comparable to HTS SQUIDs. Here we will present an overview of our devices along with our latest results.

The workshop, “Aquaculture and its role inIntegrated Coastal Zone Management” held inOstende, Belgium in April 2001, aimed to provideinformation to help develop recommendations forwise management of aquaculture in coastal andmarine environments. This paper focuses on thetwo main objectives of the workshop, 1) to aidthe development of stronger interdisciplinarycommunication between the natural and socialsciences and to improve the utility ofavailable scientific information and knowledge;and 2) to promote new perspectives on thesustainable use of coastal areas and naturalresources. The paper also summarizes thedebates following each of the three workshopthematic sessions: aquaculture and ICZM;socio-economic and political dimensions;developing sustainable production systems; andidentifies the key recommendations that may beapplied to the formulation of policy onintegrated aquaculture management in coastaland marine environments.

Between November 1993 and May 1997, the stomach contents of trawl-caught Illex coindetiiand Todaropsis eblanaefrom the edge of the continental shelf west and south-west of Ireland were examined. When visually assessed, 82.1% of the I. coindetiistomachs and 73.4% of the T. eblanaestomachs had no food remains present. In both I. coindetiiand T. eblanaestomachs with prey, crustaceans, particularly euphausids, are relatively more important as prey in smaller squid. As the squid grow, fish and squid become increasingly important prey. The small mesopelagic fish Maurolicus muelleriis a particularly important prey item of both species, occurring in 48.3% of I. coindetiiand 34.7% of T. eblanaestomachs with prey remains. M. muelleriotoliths were also often found in high numbers. In one I. coindetiistomach, 43 pairs of otoliths were found. However, this great abundance may be an over-representation of their importance in the diet as a result of the techniques used to identify prey remains in squid stomachs. Three other pelagic fish, Gadiculus argenteus, Micromesistius poutassou, Argentinasp. and the euphausid Meganyctiphanes norvegica, are also important prey of both species. Data on possible trawlnet-associated feeding are also presented, although the importance of this as a source of error in diet studies is unclear. Using data from research vessel surveys, there seems to be a peak in feeding intensity in the early morning in I. coindetti.

The microstructure of graphite arc discharge soot catalysed with Fe, Ni, Co and a mixture of Fe-Ni is investigated. It is shown that as well as single shell nanotubes and nanotube bundles, particles containing random networks of tubules and large diameter short tubules are found. Furthermore, the presence of fullerene nanocrystals directly formed during arcing is reported for the first time. The addition of a supplementary inert metallic element (Ag) to the catalysts, introduced with the aim of filling the tubules, reduces the nanotube yield significantly. Particles of Ag of spherical shape are found to be aligned and encapsulated in a carbon envelope. Energy loss spectroscopy carried out in an electron microscope reveals significant variations in the carbon-carbon bonding of the various soot morphologies which can be related to the formation site during arc discharge. Spectra from single shell nanotube bundles show an increase in the density of states on the antibonding @p bands, in agreement with electronic structure calculation predicting metallicity. Spectra from spherical soot particles indicate a similarity in the carbon-carbon bond with the C"6"0/C"7"0 fullerenes. Important variations of the carbon bonding in areas of the nanotube bundles where pentagons are introduced during the growth are also detected. Considering the observed morphologies and yield variations due to various catalysts and the presence of Ag, mechanisms contributing to the growth of the observed microstructures are proposed.

Straining of smooth tensile specimens of two precipitation hardening stainless steels over a wide range of controlled potentials in natural sea water has revealed regimes of low ductility above about — 200 mV(SCE) and below — 600 mV(SCE). The apparent loss inductility in the anodic region was attributable to dissolution and was found to be associated with pitting and crevice corrosion effects that were exacerbated when straining was conducted in acidified sea water. The embrittlement observed at more cathodic potentials, which gave rise to transgranular or intergranular failure depending upon the material and its heat treatment, is believed to be due to hydrogen that is evolved at such potentials. The occurrence of embrittlement by hydrogen in these materials, to produce similar modes of failure, was confirmed by testing smooth specimens ajtercathodic charging and both smooth and precracked specimens in gaseous hydrogen. Cracking of precracked specimens in gaseous hydrogen is complicated by the presence of δ ferrite stringers in the microstructure, which can give rise to delamination perpendicular to the principal plane of fracture if the stresses ahead of the crack are not reduced significantly by hydrogen embrittlement.

The moving behaviour of two species of abalone (H. tuberculata and H. discus hannai) on sand was studied in laboratory experiments with two size classes. Test animals of all experimental groups left solid substrata and moved across sand areas. The smaller size class (11-22 mm) was significantly less mobile than the larger size class (29-40 mm) in both species, and H. discus hannai showed higher mobility than did H. tuberculata. Lack of food was a significant incentive to move for both species and both size classes. For H. discus hannai, the stress of handling and exposure to the new environment caused increased movement that decreased as the animals acclimated. The significance of these findings for fisheries management and reseeding programmes is discussed, in particular as a possible explanation for the frequently reported 'unaccounted for' lost seed abalone.

Stomach contents of Loligo forbesi obtained from commercial landings and research cruises in Irish waters and the Irish Sea were examined. A total of 62.3% of stomachs were empty. Fish remains occurred in 73.7% of all full or partially full stomachs, with crustaceans and cephalopods occurring in 26.4% and 7.5% respectively, L. forbesi was found to consume a wide range of fish and crustacean prey. Sagittal otoliths were used to identify fish species, and vertebrate to identify families. The most frequent species by per cent occurrence sprat (Sprattus sprattus), poor cod (Trisopterus minutus), Norway pout (T. esmarkii), and transparent goby (Aphia minuta). Crustaceans were the main prey item is squid of less than 100 mm mantle length, together with small clupeids and gobies. the predominant prey of medium-sized squid (100-220 mm) was found to be gadoid and clupeid fish, while gadoids and other cephalopods were the main prey of larger squid (>220 mm). Seasonal differences in the diet were apparent but were shown to be influenced by seasonal changes in squid size. Copyright 1994, 1999 Academic Press

The feasibility of electrically conducting polymers was explored theoretically in the 1960's but has been the subject of serious research only over the past decade or so. Dr. Aldissi's book reviews the progress of this research and describes the current state of the art. Various aspects of the subject are covered such as synthesis, properties, and applications, with the author adopting a mainly descriptive style.