Microstructure control during twin roll casting of an AZ31 magnesium alloy

The existing twin roll casting technique for magnesium alloys suffers heterogeneity in both microstructure and chemistry and downstream processing is required to improve the strip quality, resulting in cost rise. In the present work, twin roll casting was carried out using an AZ31 magnesium alloy, with the application of intensive shearing melt conditioning prior to casting. The effect of process parameters such as pouring temperature and casting speed on microstructure control during casting and subsequent downstream processing was studied. Experimental results showed that the melt conditioning treatment allowed the production of AZ31 strips with uniform and refined microstructure free of centreline segregations. It was also shown that an optimized combination of pouring temperature and casting speed, in conjunction with a strip thickness control operation, resulted in uniformly distributed stored energies due to enhanced plastic deformation, which promoted recrystallization during casting and subsequent heat treatment. Strips prepared by twin roll casting and homogenization developed similar microstructural features to those prepared by twin roll casting followed by lengthy downstream processing by homogenization, hot rolling and annealing and displayed a weaker basal texture, exhibiting a potentially better formability.The EPSRC (UK

10 Gbit/s bit interleaving CDR for low-power PON

A novel, low power, downstream clock and data recovery (CDR)- decimator architecture is proposed for next generation, energy efficient 10 Gbit/s optical network units (ONUs). The architecture employs a new time division multiplexing bit-interleaving downstream concept for passive optical networks (Bi-PON) allowing early decimation of the incoming data and lowering of the processing speed to the user rate of the ONU, thus reducing the power consumption significantly

Learning to make external sensory stimulus predictions using internal correlations in populations of neurons

To compensate for sensory processing delays, the visual system must make predictions to ensure timely and appropriate behaviors. Recent work has found predictive information about the stimulus in neural populations early in vision processing, starting in the retina. However, to utilize this information, cells downstream must in turn be able to read out the predictive information from the spiking activity of retinal ganglion cells. Here we investigate whether a downstream cell could learn efficient encoding of predictive information in its inputs in the absence of other instructive signals, from the correlations in the inputs themselves. We simulate learning driven by spiking activity recorded in salamander retina. We model a downstream cell as a binary neuron receiving a small group of weighted inputs and quantify the predictive information between activity in the binary neuron and future input. Input weights change according to spike timing-dependent learning rules during a training period. We characterize the readouts learned under spike timing-dependent learning rules, finding that although the fixed points of learning dynamics are not associated with absolute optimal readouts, they convey nearly all the information conveyed by the optimal readout. Moreover, we find that learned perceptrons transmit position and velocity information of a moving bar stimulus nearly as efficiently as optimal perceptrons. We conclude that predictive information is, in principle, readable from the perspective of downstream neurons in the absence of other inputs, and consequently suggests that bottom-up prediction may play an important role in sensory processing.Comment: 36 pages, 5 figures, 3 supplemental figure

Downstream activities: The possibilities and the realities

The paper discusses the practical possibilities of achieving increased downstream processing and the policies that are commonly used for this purpose. It reviews the reasons why forward vertical integration is not always an optimal choice for extractive industry companies. It finds little support for the argument that differences in market power dictate the geography of downstream processing. Tariffs on processed products may also play only a limited role. The degree of vertical integration varies and appears to be mainly driven by production economics. Market determined processing margins fluctuate, which raises the risks of investing in downstream processing capacity. Policies for downstream processing are discussed based on experiences in four countries: India, Indonesia, Zambia, and Tanzania. In most of these cases, a very limited amount of analysis appears to have been undertaken to design the policies. Results so far seem to indicate that a number of unintended consequences dominate the outcomes

Microbial production of scleroglucan and downstream processing

Synthetic petroleum-based polymers and natural plant polymers have the disadvantage of restricted sources, in addition to the non-Biodegradability of the former ones. In contrast, eco-sustainable microbial polysaccharides, of low-cost and standardized production, represent an alternative to address this situation. With a strong globalmarket, they attracted worldwide attention because of their novel and unique physico-chemical properties as well as varied industrial applications, and many of them are promptly becoming economically competitive. Scleroglucan, a β-1,3-β-1,6- glucan secreted by Sclerotium fungi, exhibits high potential for commercialization and may show different branching frequency, side-chain length, and/or molecular weightdepending on the producing strain or culture conditions. Water-solubility, viscosifying ability and wide stability over temperature, pH and salinity make scleroglucan useful for different biotechnological (enhanced oil recovery, food additives, drug delivery,cosmetic and pharmaceutical products, biocompatible materials, etc.), and biomedical(immunoceutical, antitumor, etc.) applications. It can be copiously produced at bioreactor scale under standardized conditions, where a high exopolysaccharide concentration normally governs the process optimization. Operative and nutritional conditions, as well as the incidence of scleroglucan downstream processing will be discussed in this chapter. The relevance of using standardized inocula from selectedstrains and experiences concerning the intricate scleroglucan scaling-up will be also herein outlined.Fil: Castillo, Natalia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Valdez, Alejandra Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Fariña, Julia Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina. Universidad Nacional de Catamarca; Argentin