A Proppant Flowback Mechanical Model Based on Different Wettability of the Proppant Particle Surface

Author(s):  
Kong-jie Wang ◽  
Mian Zhang ◽  
Bo-tao Wang ◽  
Jun Shi
2021 ◽  
pp. 114251
Author(s):  
Elisa Bertolesi ◽  
Ernesto Grande ◽  
Mario Fagone ◽  
Gabriele Milani ◽  
Tommaso Rotunno
Keyword(s):  

1938 ◽  
Vol 15 (1) ◽  
pp. 114-131 ◽  
Author(s):  
J. W. S. PRINGLE

1. The campaniform sensilla on the legs of Periplaneta are similar in action to those on the palps, and respond to strains in the cuticle. 2. They are arranged in groups at the joints, with parallel orientation of the sensilla of a group. 3. Tests with various chemical substances show a complete absence of sensitivity to olfactory stimuli. 4. A theory is given of the mode of action of the sensilla in terms of a mechanical model based on their observed structure. Each group of parallel sensilla should act as a unit, responding to those forces which have a compression component of shear in the direction of their long diameters. 5. This theory makes it possible to predict the behaviour of the sensilla from their anatomical arrangement. Most if not all the groups on the legs are so arranged as to be sensitive to the forces present when the insect is standing on the ground. 6. The sensilla probably provide the basis for the sense of contact pressure postulated by Holst (1935), Hoffmann (1933), Crozier & Stier (1928-9), Fraenkel (1932) and others. 7. Comparison of this proprioceptive mechanism with that of the vertebrate limb reveals an absence of qualitative sensitivity that may have an important bearing on the question of the evolution of behaviour.


PLoS ONE ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. e0212681
Author(s):  
Jérôme Molimard ◽  
Rébecca Bonnaire ◽  
Woo Suck Han ◽  
Reynald Convert ◽  
Paul Calmels

2021 ◽  
Author(s):  
Jens Murawski ◽  
Jun She ◽  
Vilnis Frishfelds

<p>Marine micro plastic is a growing problem, because of its ability to accumulate in the environment. Reliable data of drift patterns and accumulation zones are required to estimate environmental impacts on natural protected areas, spawning areas and vulnerable habitats. H2020 project CLAIM (Cleaning Litter by developing and Applying Innovative Methods) uses model based assessments to improve the knowledge on marine pathways, sources and sinks of land emitted plastic pollution. The assessment follows a systematic approach, to derive reliable emission values for coastal sources, and to model drift and deposition pattern of micro plastics from multiple sources: car tyres, cosmetic products. A 3D modelling tool has been developed, that includes all relevant key processes, i.e. currents and wave induced transport, biofilm growth on the particle surface, sinking and sedimentation. Core engine is the HBM ocean circulation model, which has been set-up for the Baltic Sea in high resolution of 900m. Multi-years-studies (2013-2019) were performed to evaluate seasonal drift pattern and accumulation zones. Highest micro plastic concentrations were found in coastal waters, near major release locations, but transport related offshore pattern can be found as well. These follow the major pathways of deeper sea transport, but are controlled by the seasonal dynamic of biofilm growth and sinking. We introduce the model and all relevant key processes. Seasonal drift pattern are discusses in detail. Validation results in the Gulf of Riga and the Gulf of Finland provide an overview of the quality of the model to predict the distribution of micro plastics. The study includes the assessment of mitigation scenarios, of 30% micro plastic load reductions. The impacts on the ocean levels of micro plastic concentrations are studied in detail.  </p><p> </p><p> </p>


Author(s):  
Shun TAKENAKA ◽  
Tsukasa YOSHINAGA ◽  
Kazunori NOZAKI ◽  
Satoshi II ◽  
Shigeo WADA

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e95000 ◽  
Author(s):  
Clément de Loubens ◽  
Roger G. Lentle ◽  
Corrin Hulls ◽  
Patrick W. M. Janssen ◽  
Richard J. Love ◽  
...  

Author(s):  
Rahil Vali ◽  
Takashi Saito

As both the geometric and stiffness changes may occur in atherosclerosis, it is necessary to estimate respective contribution from structural and material characteristics in the stiffness index. In this study, we employ the primary mechanical model based on one of elastic shell theory, Love’s theory and look upon a blood vessel as a ring model. Furthermore in order to confirm validity of the model, the experiments were carried out on artificial tubes. The circulating circuit is applied as the circulatory system of human body including tubes, and water is designated as the working fluid of the circulating circuit. Experimental data are applied for mechanical model and mechanical parameters are identified using Downhill simplex method as the inverse problem. In this study stiffness index and damping ratio were identified and the result of Love’ theory was compared with measurement data and Donnell’s theory. The result shows that present study can confirm the measurement data with the fine approximation.


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