scholarly journals Comparison of Concentration Transport Approach and MP-PIC Method for Simulating Proppant Transport Process

Author(s):  
Junsheng Zeng ◽  
Heng Li
2020 ◽  
Vol 51 (4) ◽  
pp. 1074-1081
Author(s):  
Al obaydy & et al.

This experiment was conducted and aimed to reducing mortality and losing the weight of birds transported to the slaughter house through reducing or Transport stress removal and thus to reduce financial losses. 150 birds used almost equal weights that were divided into three treatment groups and by five replicates for each treatment is control treatment (T1) without giving anything and treatment with salicylic acid concentration 1 g / liter of drinking water (T2) and treatment with ascorbic acid (T3) concentration 0.5 g / Liter of drinking water provided 24 hours before its transport. The transport process resulted in a highly significant decrease (P ≤ 0.01) in body weight in treatment T1 as it reached 4.66%, while it reached 1.68 and 1.09% in treatment T2 and T3, respectively. The transport process led to an increase in body temperature, H / L ratio, the concentration of glucose, aspartate transaminase (AST) and alanine transaminase (ALT) in the blood serum, as the transport process led to a very significant decrease (P ≤ 0.01) in the cholesterol concentration, Uric acid, intestinal villi length and crypts depth. T2 and T3 treatments showed their ability to reduce transport stress, especially T3, where they outperformed T1 in most traits. It is concluded from the study that adding ascorbic acid by 0.5 g / L drinking water 24 hours before transporting the chicks to the slaughter house reduces the transport stress and lessen financial losses, so it is recommended to use it.


2020 ◽  
Vol 35 (6) ◽  
pp. 325-339
Author(s):  
Vasily N. Lapin ◽  
Denis V. Esipov

AbstractHydraulic fracturing technology is widely used in the oil and gas industry. A part of the technology consists in injecting a mixture of proppant and fluid into the fracture. Proppant significantly increases the viscosity of the injected mixture and can cause plugging of the fracture. In this paper we propose a numerical model of hydraulic fracture propagation within the framework of the radial geometry taking into account the proppant transport and possible plugging. The finite difference method and the singularity subtraction technique near the fracture tip are used in the numerical model. Based on the simulation results it was found that depending on the parameters of the rock, fluid, and fluid injection rate, the plugging can be caused by two reasons. A parameter was introduced to separate these two cases. If this parameter is large enough, then the plugging occurs due to reaching the maximum possible concentration of proppant far from the fracture tip. If its value is small, then the plugging is caused by the proppant reaching a narrow part of the fracture near its tip. The numerical experiments give an estimate of the radius of the filled with proppant part of the fracture for various injection rates and leakages into the rock.


Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 285
Author(s):  
Joanna Konczyk ◽  
Wojciech Ciesielski

A facilitated transport of Pb(II) through polymer inclusion membrane (PIM) containing 1,8,15,22-tetra(1-heptyl)-calixresorcin[4]arene and its tetra- and octasubstituted derivatives containing phosphoryl, thiophosphoryl or ester groups as an ion carrier was investigated. The efficiency of Pb(II) removal from aqueous nitrate solutions was considered as a function of the composition of membrane (effect of polymer, plasticizer, and carrier), feed (effect of initial metal concentration and presence of other metal ions) and stripping phases, and temperature of the process conducting. Two kinetic models were applied for the transport description. The highest Pb(II) ions removal efficiency was obtained for the membrane with tetrathiophosphorylated heptyl-calixresorcin[4]arene as an ion carrier. The activation energy value, found from Eyring plot to be equal 38.7 ± 1.3 kJ/mol, suggests that the transport process is controllable both by diffusion and chemical reaction. The competitive transport of Pb(II) over Zn(II), Cd(II), and Cr(III) ions across PIMs under the optimal conditions was also performed. It was found that the Cr(III) ions’ presence in the feed phase disturb effective re-extraction of Pb(II) ions from membrane to stripping phase. Better stability of PIM-type than SLM-type membrane was found.


Author(s):  
Kenichi Nishikawa ◽  
Ioana Duţan ◽  
Christoph Köhn ◽  
Yosuke Mizuno

AbstractThe Particle-In-Cell (PIC) method has been developed by Oscar Buneman, Charles Birdsall, Roger W. Hockney, and John Dawson in the 1950s and, with the advances of computing power, has been further developed for several fields such as astrophysical, magnetospheric as well as solar plasmas and recently also for atmospheric and laser-plasma physics. Currently more than 15 semi-public PIC codes are available which we discuss in this review. Its applications have grown extensively with increasing computing power available on high performance computing facilities around the world. These systems allow the study of various topics of astrophysical plasmas, such as magnetic reconnection, pulsars and black hole magnetosphere, non-relativistic and relativistic shocks, relativistic jets, and laser-plasma physics. We review a plethora of astrophysical phenomena such as relativistic jets, instabilities, magnetic reconnection, pulsars, as well as PIC simulations of laser-plasma physics (until 2021) emphasizing the physics involved in the simulations. Finally, we give an outlook of the future simulations of jets associated to neutron stars, black holes and their merging and discuss the future of PIC simulations in the light of petascale and exascale computing.


Author(s):  
Jessica L. Oster ◽  
Aaron K. Covey ◽  
Corey Lawrence ◽  
Max G. Giannetta ◽  
Jennifer L. Druhan

Author(s):  
Beatriz Ramos Barboza ◽  
Bin Chen ◽  
Chenfeng Li

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