title: Nb-based heterogeneous nuclei for enhanced α-Mg nucleation in Mg(-Al) alloys

authors: Bolzoni, Leandro

subjects: Cast

abstract: The effect of the introduction of in-situ formed Nb-based compounds on Al-including Mg alloys has been investigated. It is found that grain refinement is consistently achieved. Nb-based intermetallic particles are responsible of the effective heterogeneous nucleation of Al-including Mg alloys. The refining mechanism is discussed on the base of crystallography.

text: Nb-based heterogeneous nuclei for enhanced α-Mg nucleation in Mg(-Al) alloys The effect of the introduction of in-situ formed Nb-based compounds on Al-including Mg alloys has been investigated. It is found that grain refinement is consistently achieved. Nb-based intermetallic particles are responsible of the effective heterogeneous nucleation of Al-including Mg alloys. The refining mechanism is discussed on the base of crystallography.

year: 2016-04-15

title: Characteristics of temporal fluctuations in the hyperpolarized state of the cortical slow oscillation

authors: Wilson, Marcus T.

subjects: bioelectric potentials

abstract: We present evidence for the hypothesis that transitions between the low- and high-firing states of the cortical slow oscillation correspond to neuronal phase transitions. By analyzing intracellular recordings of the membrane potential during the cortical slow oscillation in rats, we quantify the temporal fluctuations in power and the frequency centroid of the power spectrum in the period of time before “down” to “up” transitions. By taking appropriate averages over such events, we present these statistics as a function of time before transition. The results demonstrate an increase in fluctuation power and time scale broadly consistent with the slowing of systems close to phase transitions. The analysis is complicated and limited by the difficulty in identifying when transitions begin, and removing dc trends in membrane potential.

text: Characteristics of temporal fluctuations in the hyperpolarized state of the cortical slow oscillation We present evidence for the hypothesis that transitions between the low- and high-firing states of the cortical slow oscillation correspond to neuronal phase transitions. By analyzing intracellular recordings of the membrane potential during the cortical slow oscillation in rats, we quantify the temporal fluctuations in power and the frequency centroid of the power spectrum in the period of time before “down” to “up” transitions. By taking appropriate averages over such events, we present these statistics as a function of time before transition. The results demonstrate an increase in fluctuation power and time scale broadly consistent with the slowing of systems close to phase transitions. The analysis is complicated and limited by the difficulty in identifying when transitions begin, and removing dc trends in membrane potential.

year: 2008

title: The contested shift to a bicultural understanding of place heritage in Aotearoa New Zealand

authors: Passey, Emma

abstract: This article explores contemporary threads in the heritage history of Aotearoa New Zealand, as we witness in real-time the emergence of alternative narratives of Indigenous heritage, in contrast to those of Western dominated modernity and colonial hegemony. Moves to actively decolonise heritage studies is creating shifts in the bicultural understanding of culture and heritage to overtly include place heritage. As this new framing emerges, wider acknowledgement of the significance of Māori heritage landscapes is growing. This is explored here in a series of four case-studies. Each account illustrates how Indigenous Māori voices have gained momentum, and reinforces how Aotearoa New Zealand is transitioning to greater bicultural appreciation through inclusion, changes in social and cultural conventions, and new interpretations of dominant narratives using tools like critical heritage studies and existing legal conventions. This evolution of heritage values is not without repeated contestation, however. Positively, increasing numbers of settler-Pākehā (non-Māori) as well as those colonised, no longer believe or accept the histories previously told. Much needed, robust, and sometimes difficult discussions are taking place, enabling New Zealanders to reconsider the significance of what heritage means to all its people.

text: The contested shift to a bicultural understanding of place heritage in Aotearoa New Zealand This article explores contemporary threads in the heritage history of Aotearoa New Zealand, as we witness in real-time the emergence of alternative narratives of Indigenous heritage, in contrast to those of Western dominated modernity and colonial hegemony. Moves to actively decolonise heritage studies is creating shifts in the bicultural understanding of culture and heritage to overtly include place heritage. As this new framing emerges, wider acknowledgement of the significance of Māori heritage landscapes is growing. This is explored here in a series of four case-studies. Each account illustrates how Indigenous Māori voices have gained momentum, and reinforces how Aotearoa New Zealand is transitioning to greater bicultural appreciation through inclusion, changes in social and cultural conventions, and new interpretations of dominant narratives using tools like critical heritage studies and existing legal conventions. This evolution of heritage values is not without repeated contestation, however. Positively, increasing numbers of settler-Pākehā (non-Māori) as well as those colonised, no longer believe or accept the histories previously told. Much needed, robust, and sometimes difficult discussions are taking place, enabling New Zealanders to reconsider the significance of what heritage means to all its people.

year: 2023-01-01