Technology for carrying out hydraulic fracturing using a new material 'nitinol'

The paper examines the causes of proppant backflow from a fracture to a well, and presents the main technologies for proppant control. The consequences of the removal of the fracture filler into the wellbore are determined. It has been noted that proppant backflow is most damaging to wells operated by electric centrifugal pumps. Existing methods of hydraulic fracturing are investigated, their disadvantages are indicated. A method has been developed for hydraulic fracturing with injection of compressed springs made of metal with the effect of 'memory' and restoring their shape under reservoir temperature stress. In the first stage, the remote section of the crack is filled with a fine fraction of ceramic proppant, and at the final stage of crack attachment, compressed springs made of nitinol material are fed. Using of material with a shape memory will allow the proppant packing to be compacted and the proppant to be 'locked' in the fracture. © Published under licence by IOP Publishing Ltd

26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

Supplementary code for paper "Translating from Na+ to Ca2+: Na/Ca-exchanger exerts Na+-dependent control over astrocytic Ca2+ oscillations"

<p>Recently accumulated evidence suggest that astrocyte signaling is linked to extracellular volume regulation and interstitial fluid drainage from the brain. Classical understanding of astrocyte activity is based on IP<sub>3</sub>-dependent calcium exchange with intracellular stores. Recent evidence shifts focus to calcium entry from extracellular space via multiple mechanisms and widens it to taking other ions into account.</p> <p>It has been hypothesized that Na/Ca-exchanger can translate activity-dependent Na<sup>+</sup> transients into modulation of Ca<sup>2+</sup> dynamics. We combine a model of IP<sub>3</sub> based  Ca<sup>2+</sup>  dynamics with a model of Ca<sup>2+</sup> flow through Na/Ca-exchanger to provide theoretical insights into the possible effects of such modulation. We find that the exchanger can provide for bidirectional Na<sup>+</sup>-dependent modulation of the sensitivity to extracellular glutamate, oscillation amplitude and frequency modulation, as well as extending the available set of dynamical regimes. The extent of the emergent Na<sup>+</sup> sensitivity is predicted to be scaled by a morphology-dependent balance between the maximal flow through the exchanger and the rate of entry from intracellular stores.</p> <p>This is the accompanying code used for the paper. How to run:<br> 1. Install Anaconda https://www.anaconda.com/products/individual<br> 2. Go to the folder with the code<br> 3. In anaconda prompt, create environment with dependencies: `conda env create -f astro-ncx-env.yaml`<br> 4. Unpack pre-computed model behavior characteristics: `tar zxf data.tgz`<br> 5. Activate the created environment: `conda activate astro-ncx`<br> 6. In anaconda prompt, use Jupyter lab server to run the attached notebook: `jupyter lab NCX+Ullah_model.ipynb`</p&gt