Thermal regime of the upper part of permafrost in the transition zone from land to sea, Western Yamal.

2017 ◽  
Keyword(s):  
Transition Zone ◽  
Thermal Regime

Thermal regime and hydrodynamics in Tunisia and Algeria

Geophysics ◽  
1991 ◽  
Vol 56 (7) ◽  
pp. 1093-1102 ◽  
Author(s):  
Hamed Ben Dhia
Keyword(s):  
Heat Flow ◽  
Transition Zone ◽  
Thermal Regime ◽  
High Heat ◽  
Hydrodynamic Regime ◽  
High Heat Flow ◽  
Normal Heat ◽  
Tectonically Active ◽  
Potential Recharge ◽  
Hydrodynamic Perturbation

The thermal regime of Algeria and Tunisia and its relation to hydrodynamics is studied by means of available geological and geothermal, and petroleum data. Heat flow densities in the area range from [Formula: see text] to [Formula: see text]. Several Paleozoic to Tertiary aquifers have been identified, together with potential recharge and discharge areas. The area is a transition zone between the African and European plates. The more tectonically active northern Alpine domain does not exhibit an obvious geothermal trend, and high heat flow anomalies that occur there may be related to structure rather than hydrodynamics. The more stable southern Saharan tectonic domain, with background heat flow of approximately [Formula: see text], exhibits anomalous zones correlated to the hydrodynamic regime with low values in recharge areas (Algerian Tinrhert and High Plateaux) and values in discharge areas (Tunisian Jeffara and Algerian Tademait). The hydrodynamic perturbation to the normal heat flow is estimated to be as great as [Formula: see text] in recharge and discharge zones.

Theoretical modeling of the regular olivine intergrowths in the mimetic paramorphosis after ringwoodite and wadsleyite

2018 ◽  
pp. 3-12
Author(s):  
B. B. Shkursky
Keyword(s):  
Transition Zone ◽  
Theoretical Modeling ◽  
Mantle Transition Zone ◽  
Misorientation Angles

Theoretical modeling of regular olivine grains misorientations in mimetic paramorphoses after ringwoodite and wadsleyite, the formation of which during the ascension of matter from the Mantle Transition Zone is expected, has been carried out. The coordinates of the misorientation axes and the misorientation angles, characterizing 10 operations of alignment in the pair intergrowths of olivine grains, eight of which are twins, are calculated. Possible conditions for the formation of mimetic paramorphoses predicted here, and the chances of their persistence are discussed. The calculated orientations are compared with the known twinning laws of olivine.

Mathematical Model of the Effective Properties of a Fiber Reinforced Composite with a Linearly Graded Transition Zone

2010 ◽  
Vol 38 (4) ◽  
pp. 286-307
Author(s):  
Carey F. Childers
Keyword(s):  
Mathematical Model ◽  
Transition Zone ◽  
Effective Properties ◽  
Local Stress ◽  
Stress And Strain ◽  
Fiber Reinforced ◽  
Strain Fields ◽  
Shear Moduli ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

Abstract Tires are fabricated using single ply fiber reinforced composite materials, which consist of a set of aligned stiff fibers of steel material embedded in a softer matrix of rubber material. The main goal is to develop a mathematical model to determine the local stress and strain fields for this isotropic fiber and matrix separated by a linearly graded transition zone. This model will then yield expressions for the internal stress and strain fields surrounding a single fiber. The fields will be obtained when radial, axial, and shear loads are applied. The composite is then homogenized to determine its effective mechanical properties—elastic moduli, Poisson ratios, and shear moduli. The model allows for analysis of how composites interact in order to design composites which gain full advantage of their properties.

Lithostratigraphy of the Kweekvlei Formation (Witteberg Group), Cape Supergroup

2017 ◽  
Vol 120 (3) ◽  
pp. 421-432 ◽  
Author(s):  
C. Browning ◽  
M. Reid
Keyword(s):  
South Africa ◽  
Transition Zone ◽  
Distal Part ◽  
Vascular Plant ◽  
Trace Fossil ◽  
Plant Debris ◽  
Lower Carboniferous ◽  
Fossil Assemblage ◽  
Low Diversity ◽  
Storm Wave

AbstractThe Lower Carboniferous, probably Tournaisian, Kweekvlei Formation is part of the Witteberg Group (Cape Supergroup) of South Africa. Together with the overlying Floriskraal Formation, it forms an upward-coarsening succession within the Lake Mentz Subgroup. Sedimentary features of the Kweekvlei Formation suggest deposition in a storm-wave dominated marine setting, within the storm-influenced, distal part of an offshore transition zone environment. This predominantly argillaceous formation preserves a low diversity trace fossil assemblage. Reworked vascular plant debris (including the problematic genus Praeramunculus sp.) and a shark spine have been reported for the Kweekvlei Formation. There are no known stratigraphic equivalents in South Africa.

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