111 research outputs found
Characteristic Energy Losses with High Energy Electrons up to 2.5 MeV
Some aspects of the influence of the energy of the incident electrons in electron energy loss spectroscopy (EELS) are considered. It is shown that this method of analysis used in high voltage electron microscopy, permits one to observe, with a better edge jump ratio than at lower accelerating voltages, the characteristic edges. One important question is to eliminate artefacts in the counting and to record only electrons from the true spectrum. Some recent examples are given. One of them concerns extended energy loss fine structures (EXELFS). It seems high voltage electron microscopy (HVEM) could be very useful in this domain
A statistical comparison of the AMIE derived and DMSP‐SSIES observed high‐latitude ionospheric electric field
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95462/1/jgra18089.pd
Temporal evolution of the transpolar potential after a sharp enhancement in solar wind dynamic pressure
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95384/1/grl23891.pd
Saturation of the polar cap potential: Inference from Alfvén wing arguments
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95262/1/jgra18814.pd
Attribution and contestation: Relations between elites and other social groups
In this article we explore the often ambiguous relations between elites and other social groups, both subordinate and of relatively equal standing. The article draws on two distinctive ethnographic cases: the white Franco-Mauritian elite, and the expert elite of management consultants in a Western European context. Our analysis of the two cases provides insights into how the power and status of elites is both contested and attributed by the people they interact with and relate to in concrete, yet substantially different contexts and situations. The aim is to show how the position and power of different kinds of elites is relationally negotiated and achieved. As we argue, a better understanding of the role of other social groups in the attribution, maintenance and contestation of status is relevant for understanding both more traditional economic elites and expert elites without tight networks
Statistical study of the subauroral polarization stream: Its dependence on the cross–polar cap potential and subauroral conductance
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95602/1/jgra19576.pd
Applications of yeast flocculation in biotechnological processes
A review on the main aspects associated with yeast flocculation and its application
in biotechnological processes is presented. This subject is addressed following three
main aspects – the basics of yeast flocculation, the development of “new” flocculating yeast
strains and bioreactor development. In what concerns the basics of yeast flocculation, the
state of the art on the most relevant aspects of mechanism, physiology and genetics of yeast
flocculation is reported. The construction of flocculating yeast strains includes not only the
recombinant constitutive flocculent brewer’s yeast, but also recombinant flocculent yeast
for lactose metabolisation and ethanol production. Furthermore, recent work on the
heterologous β-galactosidase production using a recombinant flocculent Saccharomyces
cerevisiae is considered. As bioreactors using flocculating yeast cells have particular properties,
mainly associated with a high solid phase hold-up, a section dedicated to its operation is
presented. Aspects such as bioreactor productivity and culture stability as well as bioreactor
hydrodynamics and mass transfer properties of flocculating cell cultures are considered.
Finally, the paper concludes describing some of the applications of high cell density
flocculation bioreactors and discussing potential new uses of these systems.Fundação para a Ciência e a Tecnologia (FCT) – PRAXIS XXI - BD11306/97
The contribution of environmental factors to fish assemblages in the Río Acahuapa, a small drainage in Central America
Randomized clinical trials of dental bleaching – Compliance with the CONSORT Statement: a systematic review
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