CAFTURE AND RECYCLE OF BYPASSING BUBBLE GAS IN A FLUIDIZED BED: THE “BUBBLE EATER”

The bubble eater is a device which can sense, capture, and recycle bubble gas in a bubbling fluidized bed. The theory describing the enhancement of reactant gas conversion are presented and illustrated by means of a numerical example.     

In vitro studies on the use of clay, clay minerals and charcoal to adsorb bovine rotavirus and bovine coronavirus

Rotaviruses are the leading cause and coronaviruses are the major contributors of acute gastroenteritis in the young of various mammalian and avian species. Despite numerous trials and decades of research, vaccines have limited efficacy particularly for calves. As an alternative method of controlling infection, we have investigated broad spectrum antiviral agents that are not discriminatory among various viruses. This report involves testing a variety of adsorbent agents including charcoal, clay, and clay minerals to adsorb rotavirus and coronavirus in vitro. Results revealed that all the adsorbent agents had good to excellent capability of adsorbing rotavirus and excellent capability of adsorbing coronavirus. Percent adsorptions ranged from 78.74% to 99.89% for rotavirus and 99.99% for coronavirus; while sand (negative control) was < 0.01%. A high affinity binding was present as determined by a low percent desorption (0.06-3.09%). However, the adsorbent bound virus complex retained, and may have actually enhanced, infectivity.     

The failure of an F/A-18 trailing edge flap hinge

During a flight over sea, the right-hand trailing-edge flap (TEF) from an RAAF F/A-18 separated. Although the flap was not recovered, the mode of failure suggested that the outboard hinge lug was first to fail. A fleet-wide inspection of the TEF outer hinge lugs disclosed two other cracked hinge lugs. Examination of these cracks revealed that they had propagated as the result of a combination of corrosion and fatigue, in that the corrosive environment appeared to have accelerated the fatigue crack growth rate. Laboratory experiments indicated that, in a salt solution, the 7050 aluminium alloy from which the lugs were manufactured is susceptible to corrosion fatigue and that the observed cracking matched that on the cracked lugs: corrosion fatigue was therefore suspected to have been a contributing factor in the unexpected failure. Quantitative fractography on the fatigue cracks, combined with several assumptions and deductions, including information about the failure size of the crack gained from witness marks found on the monoball bearing of the failed TEF, led to an estimate of the fatigue crack growth rate. This crack growth rate and the short service life clearly indicated the limitations of the then-current non-destructive inspection (NDI) technique, and a more sensitive inspection method was developed to assist in the maintenance of adequate RAAF flying hours between inspections. This failure investigation provided an excellent example of how fractography, laboratory experiments and NDI can be combined to determine a possible cause of failure and to establish remedial measures for the fleet.     

A 150 MHz 0.6 μm BiCMOS superscalar microprocessor

An implementation of the Pentium microprocessor architecture in 0.6 μm BiCMOS technology is described. Power dissipation is reduced and performance is enhanced over the previous generation. Processor features, implementation technology, and circuit techniques are discussed. An internal clock rate of 150 MHz is achieved at 3.7 V and -55°C     

The hierarchies of knowledge and the mathematics of discovery

Rather than attempting to characterize a relation of confirmation between evidence and theory, epistemology might better consider which methods of forming conjectures from evidence, or of altering beliefs in the light of evidence, are most reliable for getting to the truth. A logical framework for such a study was constructed in the early 1960s by E. Mark Gold and Hilary Putnam. This essay describes some of the results that have been obtained in that framework and their significance for philosophy of science, artificial intelligence, and for normative epistemology when truth is relative.I am indebted to Kevin Kelly for several years of happy conversation from which the perspective and views of this paper grew, for comments on a draft of the paper, and for constructing some of the illustrations. A fellowship from the John Simon Guggenheim Memorial Foundation provided the liberty to write this paper. It was first presented in the Turing Colloquium, 1990.     

Microstructural changes in concretes with sulfate exposure

In prior papers the responses of concretes to 50,000 ppm MgSO₄ exposure depending on cement type, w/cm and the presence of slag were described. The present paper completes this analysis by examining the effects of immersion of concretes produced using slag blended cements, in solutions containing 50,000 ppm of sodium sulfate. The spatial evolution of microstructure associated with carbonation and sulfate attack show differences which can be related to the nature of the cation associated with the sulfate, the cement type, and the w/cm ratio.     

湖北民营企业竞争力状况与提升策略分析

描述了湖北省民营企业的现状和特点,在此基础上分析了其竞争力的表现及原因,最后从企业层面和宏观层面提出了相应的对策.