1,409 research outputs found
Polymer multimode waveguide optical and electronic PCB manufacturing
No full textThe paper describes the research in the £1.3 million IeMRC Integrated Optical and Electronic Interconnect PCB Manufacturing (OPCB) Flagship Project in which 8 companies and 3 universities carry out collaborative research and which was formed and is technically led by the author. The consortium’s research is aimed at investigating a range of fabrication techniques, some established and some novel, for fabricating polymer multimode waveguides from several polymers, some formulations of which are being developed within the project. The challenge is to develop low cost waveguide manufacturing techniques compatible with commercial PCB manufacturing and to reduce their alignment cost. The project aims to take the first steps in making this hybrid optical waveguide and electrical copper track printed circuit board disruptive technology widely available by establishing and incorporating waveguide design rules into commercial PCB layout software and transferring the technology for fabricating such boards to a commercial PCB manufacturer. To focus the research the project is designing an optical waveguide backplane to tight realistic constraints, using commercial layout software with the new optical design rules, for a demonstrator into which 4 daughter cards are plugged, each carrying an aggregate of 80 Gb/s data so that each waveguide carries 10 Gb/s
A health survey of farmed red-claw crayfish, Cherax quadricarinatus (von Martens), in tropical Australia
No full textA survey of seven Cherax quadricarinatus farms in north Queensland was conducted to ascertain the disease status of this industry. Cherax baculovitus (CBV) was found in six farms, with a prevalence of 5.9 to 59.1%. A chronic bacteraemia was common in two farms which exhibited the highest prevalence of CBV and Psorospermium sp. A microsporidian infected 4.5% of crayfish from one farm exhibiting CBV/bacteraemia.
A hepatopancreocyte nuclear lesion was caused by Cherax Giardiavirus-like virus (CGV) similar to the Giardiavirus of the Totiviridae. Cherax Giardiavirus-like virus was common to all farms surveyed with the highest prevalence being 52.3%.
Chronic, low-grade mortalities were experienced at one farm infected by the
CBVbacteraemia disease syndrome. A number of agents were associated with moribund crayfish including CBV, bacteria, CGV, Psorospermium sp., rickettsiales, and an endoparasitic ciliate. All pathogens appeared capable of killing the adult crayfish. Necrosis of eyes was common in crayfish from the same farm. Externally, the eye lesions were brown to orange, and progressed to fulminant infections totally eroding the infected eye. Psorospermium sp. and heavy bacterial loads resulted in massive granuloma formation and relocation of the black melanin of the infected eyes. Aeromonas hydrophila and Aeromonas sobria were regularly isolated from the eye lesions and the haemolymph. On some occasions faecal coliforms including Plesiomonas shigelloides, Klebsiella pneumoniae and Shewanella putrefaciens were isolated
The Larval Development of Macrobrachium Australiense Holthuis, 1950 (Decapoda, Ρalaemonidae), Reared in the Laboratory
No full textLes stades larvaires de Macrobrachium australiense Holthuis, 1950 sont décrits et comparés à ceux d'autres espèces de Palaemonidae. Λί. australiense a une vie larvaire abrégée de trois stades, s'étendant sur environ six jours avant que la métamorphose au premier stade post-larvaire n'ait lieu. En ce qui concerne le développement larvaire, M. australiense appartiendrait à la deuxième classe de Sollaud (1923) qui comprend les Palaemonidae d'eau douce à courte vie larvaire. Pourtant M. australiense produit un nombre relativement grand de petits oeufs, ce qui caractérise plutôt les espèces marines. Il est possible que ces observations indiquent que M. australiense n'est venu de l'estuaire à l'eau douce qu'à une époque relativement récente
The Chance and Probability Concepts Project
No full textThis article, created by D.R. Green, describes an investigation of what concepts and intuitions concerning random processes are present in the minds of children of varying abilities across the 11-16 age range. The ability to list permutations, combinations and arrangements is also being investigated. The author states, "Over the past two decades the topic of 'Probabilityâ has been brought into the mathematics curriculum but it may be that this is more an empty gesture rather than a sound strategy." This article can help to alleviate many of the struggles in teaching probability concepts. The article is pitched at a more elementary audience, but is still a perfect resource for almost anyone teaching in the field
Achieving 10 ps coincidence time resolution in TOF-PET is an impossible dream
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.RST/Radiation, Science and TechnologyRST/Medical Physics & Technolog
The zoeal stages and megalopa of Portunus rubromarginatus (lanchester) (decapoda: Portnnidae), reared in the laboratory
No full textThe present state of knowledge concerning Portunus larvae is reviewed, and the three zoeal and the megalopa stages of P. rubromarginatus are described and figured. Details of appendage setation are tabulated. This species is unusual amongst known Portunus spp. in having only three zoeal stages and, like other Portunus spp. but in contrast with other Portuninae, it has 4 + 4, or 4 + 1 + 4, setae on the posterior telson border.When compared with larvae of the five other Indo-West Pacific Portunus species whose larvae are known P. rubromarginatus zoeae are readily distinguished from all, except P. hastatoides, using the key features given by Kurata (1975). Comparison was made between first zoeae of these two species, and also of P. pelagicus and P. sanguinolentus, using larvae reared by the authors. It was found telson characters alone allow distinction between larvae of these four species. These characters are tabulated.P. rubromarginatus megalopae differ from those known for congenitors in having a large spine on the uchium of the first pereiopod, but not on the carpus, and in having relatively very small sternal cornuae.Several of these features disagree with those previously thought to characterise larval Portuninae or Portunus species
Disc electrophoresis of the haemolymph proteins of some portunid crabs (decapoda: portunidae)-I. Effects of storage
No full textAbstract1.The electrophoretic patterns of haemolymph proteins from 12 species of portunid crabs are described.2.A comparison of haemocyanin mobilities from stored and fresh haemolymph indicated that mobility may be decreased after snap freezing and then storing at - 10°C.3.Similar haemocyanin mobilities were recorded from 2 gel lengths and from both sexes.4.Frozen haemolymph produced smaller clots associated with a higher concentration of serum haemocyanin than did fresh haemolymph
The zoeal stages of pilumnopeus serratifrons (Kinahan, 1856) (brachyura: Xanthidae) reared under laboratory conditions
No full textPilumnopeus serratifrons reared in seawater of 34%o at 25°C passed through three zoeal stages in 12 days prior to moulting to the megalopa. Wear (1968) described the first zoea of this species reared from New Zealand specimens. That stage is redescribed here, differences from Wear’s (l.c.) material are noted, and the remaining zoeal stages are described and figured. Zoea of P. serratifrons are most readily distinguished from those of its congenor P. indicus by the former having lateral carapace spines and having lateral processes on the third abdominal segment. The position of P. serratifrons larvae in xanthid species-groups suggested by various authors is summarized
The effect of salinity and temperature on the larval development of the freshwater prawn, Macrobrachium australiense Holthuis, 1950 from south eastern Queensland, Australia
No full textLarvae of the freshwater prawn Macrobrachium australiense were reared to postlarvae at various combinations of salinity and temperature (salinity, 0 to 35‰; temperature, 15 to 35°C). Metamorphosis was not recorded at salinities higher than 15‰. However, salinities within the range 0 to 15‰ did not markedly affect survival. No larvae metamorphosed at 15 or 35°C but the rate of development was highly dependent on temperature within the range of 20 to 30°C, being fastest at 30°C, slowest at 20°C
Description of the later zoeal stages and megalopa of charybdis truncata (Fabricius, 1798) (Crustacea: Portunidae)
No full textCharybdis truncata reared in the laboratory passed through 6 zoeal stages in 20 days (at 26°C and in water of 35% salinity) before metamorphosis to the megalopa. Kurata (1975) gave brief descriptions of the first three zoeae of this species, these are supplemented here with details of appendage structure and setation, and the remaining zoeae and megalopa are described. Comparison is made with other species by means of a key to the first zoeae of 10 Charybdis sp. Those features which allow differentiation of the megalopae of the three Charybdis sp. from Australia whose complete larval development is known, are discussed. C. truncata larval stages are closely similar to those of C. callianassa
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