A search for constraints on lithospheric net rotation in 2D convection simulations

2021 ◽  
Author(s):  
Suzanne Atkins ◽  
Nicolas Coltice
Keyword(s):  
Reference Frames ◽  
Plate Motion ◽  
Model Parameters ◽  
Motion Model ◽  
Motion Models ◽  
The Third ◽  
The Earth ◽  
Geological Past ◽  
Wide Range ◽  
Third Dimension

<p>Net rotation is the process whereby the entire lithosphere can rotate with respect to the Earth’s mantle. The plates and continents retain their location with respect to each other, but they change their position with respect to global reference frames such as the Earth’s magnetic dipole, and structures in the Earth’s mantle such as plumes and hotspots. Constraining lithospheric net rotation is therefore one factor in building an absolute plate motion model. However, the amount of net rotation occurring at present day is poorly contained, and the drivers of net rotation are very poorly understood. Many absolute plate motion models therefore attempt to minimise net rotation, because there is no way to constrain rotation in the geological past. </p><p> </p><p>In previous geodynamical studies, the presence of thick continents and large viscosity contrasts were found to be controlling factors in the development of net rotation. We investigate the effects of different convection parameters and tectonic states on the magnitude and evolution of net rotation in 2D simulations. The use of 2D simulations allows us to run enough simulations to study a wide range of model parameters. We intend to compare our 2D conclusions with 3D simulations, to investigate how much of a difference the third dimension makes.</p><p> </p><p>We find that net rotation varies on much shorter timescales than any other geodynamic feature. Net rotation is not cleanly correlated with any tectonic behaviours or settings, and that the magnitude and duration is unpredictable. We do however find that the distribution of net rotation within the lifetime of a particular simulation is Gaussian, with standard deviation dependent on the viscosity structure and contrasts of the simulation, in agreement with previous studies. However, in contrast to previous studies, the presence and thickness of continents makes very little difference to the speed of lithospheric rotation, although this may be because we are working in 2D. If the 2D results are also relevant in 3D, net rotation is a continuously varying and unpredictable value, but with a predictable statistical range. This may provide a way to better constrain net rotation for plate motion models.</p>

Next Generation System in a Package Manufacturing by Embedded Chip Technologies

2010 ◽  
Vol 7 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Lars Boettcher ◽  
D. Manessis ◽  
S. Karaszkiewicz ◽  
A. Ostmann ◽  
H. Reichl
Keyword(s):  
Copper Substrate ◽  
Next Generation ◽  
Generation System ◽  
Standard Type ◽  
Passive Components ◽  
The Third ◽  
Chip Technology ◽  
Wide Range ◽  
Third Dimension ◽  
Embedded Chip

The embedding of active and passive components offers a wide range of benefits and potentials. With the use of laminate based technology concepts, components can be moved from surface mount into the build-up layers of substrates by embedding and thereby the third dimension will be available for further layers or assemblies. This paper will briefly discuss the necessary process steps of the embedded chip technology and more importantly it will focus on new efforts to actually use chip embedding concepts for the realization of standard-type industrial quad flat packages with embedded chips (embedded chip QFN). Chips of 50 μm thickness, a pad pitch of 100 μm, and pad size of 85 μm are die bonded to a copper substrate and subsequently embedded in RCC (resin coated copper) layers by using vacuum lamination. The resulting QFN packages are only 160 μm thick and provide standard pads at 400 μm pitch and a total number of 84 I/Os with dimensions of 10 × 10 mm2. All embedded chip QFN packages at the prototype level are manufactured in 250 × 300 mm2 panels.

scholarly journals On application of asymmetric Kan-like exact equilibria to the Earth magnetotail modeling

2018 ◽  
Vol 36 (2) ◽  
pp. 641-653 ◽  
Author(s):  
Daniil B. Korovinskiy ◽  
Darya I. Kubyshkina ◽  
Vladimir S. Semenov ◽  
Marina V. Kubyshkina ◽  
Nikolai V. Erkaev ◽  
...  
Keyword(s):  
Current Sheet ◽  
Vertical Plane ◽  
Magnetic Flux Tube ◽  
Model Parameters ◽  
Specific Class ◽  
The Earth ◽  
Cluster Data ◽  
Proton Temperature ◽  
Sheet Bending ◽  
Wide Range

Abstract. A specific class of solutions of the Vlasov–Maxwell equations, developed by means of generalization of the well-known Harris–Fadeev–Kan–Manankova family of exact two-dimensional equilibria, is studied. The examined model reproduces the current sheet bending and shifting in the vertical plane, arising from the Earth dipole tilting and the solar wind nonradial propagation. The generalized model allows magnetic configurations with equatorial magnetic fields decreasing in a tailward direction as slow as 1∕x, contrary to the original Kan model (1∕x3); magnetic configurations with a single X point are also available. The analytical solution is compared with the empirical T96 model in terms of the magnetic flux tube volume. It is found that parameters of the analytical model may be adjusted to fit a wide range of averaged magnetotail configurations. The best agreement between analytical and empirical models is obtained for the midtail at distances beyond 10–15 RE at high levels of magnetospheric activity. The essential model parameters (current sheet scale, current density) are compared to Cluster data of magnetotail crossings. The best match of parameters is found for single-peaked current sheets with medium values of number density, proton temperature and drift velocity.

The Colonial Documentary Film in South and South-East Asia

2017 ◽  
Keyword(s):  
East Asia ◽  
Subject Matter ◽  
Documentary Film ◽  
East Asian ◽  
South East Asia ◽  
Post Colonial ◽  
Historical Perspectives ◽  
The Third ◽  
Wide Range ◽  
Global Understanding

Writing from a wide range of historical perspectives, contributors to the anthology shed new light on historical, theoretical and empirical issues pertaining to the documentary film, in order to better comprehend the significant transformations of the form in colonial, late colonial and immediate post-colonial and postcolonial times in South and South-East Asia. In doing so, this anthology addresses an important gap in the global understanding of documentary discourses, practices, uses and styles. Based upon in-depth essays written by international authorities in the field and cutting-edge doctoral projects, this anthology is the first to encompass different periods, national contexts, subject matter and style in order to address important and also relatively little-known issues in colonial documentary film in the South and South-East Asian regions. This anthology is divided into three main thematic sections, each of which crosses national or geographical boundaries. The first section addresses issues of colonialism, late colonialism and independence. The second section looks at the use of the documentary film by missionaries and Christian evangelists, whilst the third explores the relation between documentary film, nationalism and representation.

Pèlerinages barrésiens

2013 ◽  
pp. 116-123
Author(s):  
Claire Bompaire-Evesque
Keyword(s):  
Large Scale ◽  
The Self ◽  
Joan Of Arc ◽  
The Third ◽  
National Importance ◽  
The Earth ◽  
Third Stage ◽  
The Dead

This article is a inquiry about how Barrès (1862-1923) handles the religious rite of pilgrimage. Barrès stages in his writings three successive forms of pilgrimage, revealing what is sacred to him at different times. The pilgrimage to a museum or to the birthplace of an artist is typical for the egotism and the humanism of the young Barrès, expressed in the Cult of the Self (1888-1891). After his conversion to nationalism, Barrès tries to unite the sons of France and to instill in them a solemn reverence for “the earth and the dead” ; for that purpose he encourages in French Amities (1903) pilgrimages to historical places of national importance (battlefields; birthplace of Joan of Arc), building what Nora later called the Realms of Memory. The third stage of Barrès’ intellectual evolution is exemplified by The Sacred Hill (1913). In this book the writer celebrates the places where “the Spirit blows”, and proves open to a large scale of spiritual forces, reaching back to paganism and forward to integrative syncretism, which aims at unifying “the entire realm of the sacred”.

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