BACKGROUND Loads acting on scoliotic spines are thought to be asymmetric and involved in progression of the scoliotic deformity; abnormal loading patterns lead to changes in bone and disc cell activity and hence to vertebral body and disc wedging. At present however there are no direct measurements of intradiscal stresses or pressures in scoliotic spines. The aim of this study was to obtain qua...

Purpose: The aim of the study is to determine stress distribution on preloaded implant-abutment screws in three different implant systems under simulated occlusal loads. Materials and methods: Three abutments to implant internal hex joint systems were simulated by using the 3-dimensional finite element analysis; (1) Nobel Biocare replace tapered (2) Uniti (3) Lifecare self-threaded tapered ceme...

The “Leipzig Wind Profile” is a unique example of a representative wind distribution in the frictional layer which resulted from MILDNER’S set of 28 pilot-balloon observations with two theodolites on October 20, 1931, near Leipzig for a stable weather situation. It is shown, that the vectors of geostrophic motion and ground drag follow from the wind profile when a scalar austausch is assumed. T...

The eigenvalue approach has been employed to find the analytical expressions for displacements and stresses at any point of an infinite initially stressed orthotropic elastic medium with the effect of couple stress. A plain strain problem has been studied. New closed forms of displacement and stress components have been obtained. The variations of the displacements and stresses with horizontal ...

knowledge of the orientation of horizontal in situ stresses is important to some areas of oil and gas field development plans. borehole breakouts observed in image logs and drilling-induced fractures are the main parameters for the determination of the stresses’ directions in situ. in this work, the orientations of borehole breakouts were investigated as a function of depth in oil wells a and b...

Australia has a huge resource of hot dry rock, most of which is located in Central Australia. As a first step towards experimental field testing of HDR development in Australia, in-situ stresses and natural fractures in Central Australia are being characterised. Preliminary results indicate that three stress regimes may co-exist in Central Australia, with maximum horizontal in-situ stress being...

Fluid injection in deep geological formations usually induces microseismicity. In particular, industrial-scale injection of CO2 may induce a large number of microseismic events. Since CO2 is likely to reach the storage formation at a lower temperature than that corresponding to the geothermal gradient, both overpressure and cooling decrease the effective stresses and may induce microseismicity....

Multi-stage hydraulic fracturing of horizontal wells is the main stimulation method in recovering gas from tight shale gas reservoirs, and stage spacing determination is one of the key issues in fracturing design. The initiation and propagation of hydraulic fractures will cause stress redistribution and may activate natural fractures in the reservoir. Due to the limitation of the analytical met...