Advances and challenges in geotectonic modelling

2014 ◽  
Vol 185 (3) ◽  
pp. 147-168 ◽  
Author(s):  
Evgene Burov ◽  
Thomas Francois ◽  
Philippe Yamato ◽  
Sylvie Wolf

AbstractThermo-mechanical numerical modelling becomes a universal tool for studying short- and long-term lithosphere processes, validating and verifying geodynamic and geological concepts and putting stronger constraints on the observational data. State-of-the-art models account for rheological and mineralogical structure of the lithosphere, implement high resolution calculations, and their outputs can be directly matched with the geological and geophysical observations. Challenges of these models are vast including understanding of the behavior of complex geological systems and processes, parameterization of rheological parameters and other rock properties for geological conditions, not forgetting a large number of future methodological breakthroughs such as the development of ultra-high resolution 3D models coupled with thermodynamic processes, fluid circulation and surface processes. We here discuss both geological and geodynamic applications of the models, their principles, and the results of regional modelling studies focused on rifting, convergent and transform plate boundaries.

Author(s):  
Veronika Ustohalova ◽  
Christian Ku¨ppers

The risk of radioactive contamination in the biosphere surrounding the Asse salt mine has been assessed to determine the possible radioactive exposure to humans if the mine collapses. Geological conditions and anthropogenic activities have made the mine instable and allow salt-saturated ground water to seep in. This uncontrolled brine inflow significantly increases the risk of the mine collapsing. If the mine collapses, the brine will be pressed into groundwater, where the radionuclides can migrate into the biosphere and cause radioactive exposure. The key issue discussed in this paper is estimating the short- and long-term radiation burden for humans under several possible scenarios of radionuclide release. Only a radioecological model able to quantify and estimate processes taking place can generate usable results. This work develops the radioecological model describing both radionuclide migration and the resulting radiological exposure along several exposition pathways. Development of the model took into account the sorption processes, solubility limits and special aspects of decay chain migration. The radiological exposure was estimated under non-equilibrated conditions for the case of short-time expositions. At the end of this paper, the model’s background, the results of the computations and a comparison of several scenarios will be presented.


2021 ◽  
Vol 2 (3) ◽  
pp. 332-341
Author(s):  
Natalya A. Nemova ◽  
Aleksander V. Reznik ◽  
Vladimir N. Kapov

The integrated digitalization of the mining enterprise can provide a positive effect from the optimization of the relationships between the elements of the mining system. Digitalization involves the transition from fragmentary automation of individual stages or processes to fully automated production, controlled in real time by intelligent systems. 3D models, including geological and structural analysis and geodynamic modeling of the geological structures of the deposit, should be used for a more accurate and objective view of the state of the rock mass and its changes over time. The creation of an integrated geomechanical model of the field, including a geological model, models of rock mass and rock properties, structural, hydrogeological, and others, allows for current monitoring and long-term forecast of the stress-strain state of the geomedium of mining enterprises.


Swiss Surgery ◽  
2001 ◽  
Vol 7 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Robert ◽  
Mariéthoz ◽  
Pache ◽  
Bertin ◽  
Caulfield ◽  
...  

Objective: Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease. Methods: From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue - mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery. Results: There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT - with follow-ups averaging two years (0.5-8) - are receiving thyroxin substitution. Conclusions: There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.


Author(s):  
Ian Neath ◽  
Jean Saint-Aubin ◽  
Tamra J. Bireta ◽  
Andrew J. Gabel ◽  
Chelsea G. Hudson ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document