title: Diversity in Central Asia: Culture, transition & entrepreneurship

authors: Lasch, Frank

subjects: transition

abstract: With the demise of the USSR in 1991, five new countries became independent in Central Asia. This study presents an overview about transition, emergence and nature of entrepreneurship in a world’s region that displays amongst the most important energy resources in gas and oil.

text: Diversity in Central Asia: Culture, transition & entrepreneurship With the demise of the USSR in 1991, five new countries became independent in Central Asia. This study presents an overview about transition, emergence and nature of entrepreneurship in a world’s region that displays amongst the most important energy resources in gas and oil.

year: 2009-06

title: The linear stability of line-tied coronal magnetic fields

authors: Foote, B.J.

abstract: The problem of the linear stability of cylindrically symmetric force-free magnetic equilibria is addressed. The aim is to quantify the severity of ideal MHD disturbances on a variety of line-tied coronal equilibria. Accordingly methods are developed which determine, at high spatial resolution, the dominant eigenmodes of the problem. We first introduce a family of equilibrium force-free fields parameterized by the local dimensionless twist T = rν which includes the well-known Gold-Hoyle field in the case ν = 0. The stability problem is then formulated, and the numerical techniques required for its solution are derived. As a preliminary test of our methods we present convergence results for the critical length of the Gold-Hoyle field, obtaining the result lc = 2.46π (dimensionless units). Next, the severity of the instability is quantified. The kink instability (m = 1) is found to be weak even for long lengths (l ≳ 4lc), generating dimensionless force eigenvalues less than O(10-2). The Gold-Hoyle field is shown to be the most unstable member of the family for large l, yet is the most susceptible to line-tying and so possesses the longest critical length. Preliminary investigations for higher m have not yielded instabilities for the moderate tube lengths of interest. The significance of these results to flare theories cannot be known definitively without results from finite-amplitude studies. Our results show, however, that the power release over the linear phase is at least three orders of magnitude below dimensional expectation. This implies that unstable coronal flux tubes cannot be expected to collapse violently on the MHD time scale.

text: The linear stability of line-tied coronal magnetic fields The problem of the linear stability of cylindrically symmetric force-free magnetic equilibria is addressed. The aim is to quantify the severity of ideal MHD disturbances on a variety of line-tied coronal equilibria. Accordingly methods are developed which determine, at high spatial resolution, the dominant eigenmodes of the problem. We first introduce a family of equilibrium force-free fields parameterized by the local dimensionless twist T = rν which includes the well-known Gold-Hoyle field in the case ν = 0. The stability problem is then formulated, and the numerical techniques required for its solution are derived. As a preliminary test of our methods we present convergence results for the critical length of the Gold-Hoyle field, obtaining the result lc = 2.46π (dimensionless units). Next, the severity of the instability is quantified. The kink instability (m = 1) is found to be weak even for long lengths (l ≳ 4lc), generating dimensionless force eigenvalues less than O(10-2). The Gold-Hoyle field is shown to be the most unstable member of the family for large l, yet is the most susceptible to line-tying and so possesses the longest critical length. Preliminary investigations for higher m have not yielded instabilities for the moderate tube lengths of interest. The significance of these results to flare theories cannot be known definitively without results from finite-amplitude studies. Our results show, however, that the power release over the linear phase is at least three orders of magnitude below dimensional expectation. This implies that unstable coronal flux tubes cannot be expected to collapse violently on the MHD time scale.

year: 1990

title: A newly-available resource for historians of early New Zealand: The Marist Missionary Letters (1838-54)

authors: Jennings, William

abstract: The 7000 pages of primary documents of the Lettres reçues d’Océanie constitute a vast new source for the study of the Pacific during the period 1838-54. Published in 2009 after sixteen years of transcription, the Lettres are the collected correspondence of the first French Marist missionaries to New Zealand and other Pacific islands. In the words of Pacific historian Hugh Laracy, they are ‘the single most important foundational contribution to Pacific history in its fullest extent since J. C. Beaglehole’s magisterial editions of James Cook’s Journals. About 2000 of those pages are transcripts of letters written in New Zealand that open up a fresh perspective of life before the wars of the 1860’s. This paper will locate the early French Marist Māori mission within the context of New Zealand public history before exploring how the Lettres reçues d’Océanie can complement existing views of early colonial New Zealand. To better contextualise the correspondence, it would be useful to begin with a brief background of the Marists’ presence in New Zealand.

text: A newly-available resource for historians of early New Zealand: The Marist Missionary Letters (1838-54) The 7000 pages of primary documents of the Lettres reçues d’Océanie constitute a vast new source for the study of the Pacific during the period 1838-54. Published in 2009 after sixteen years of transcription, the Lettres are the collected correspondence of the first French Marist missionaries to New Zealand and other Pacific islands. In the words of Pacific historian Hugh Laracy, they are ‘the single most important foundational contribution to Pacific history in its fullest extent since J. C. Beaglehole’s magisterial editions of James Cook’s Journals. About 2000 of those pages are transcripts of letters written in New Zealand that open up a fresh perspective of life before the wars of the 1860’s. This paper will locate the early French Marist Māori mission within the context of New Zealand public history before exploring how the Lettres reçues d’Océanie can complement existing views of early colonial New Zealand. To better contextualise the correspondence, it would be useful to begin with a brief background of the Marists’ presence in New Zealand.

year: 2012