Effects of wall temperature and temperature-dependent viscosity on maximum spreading of water-in-oil emulsion droplet

Author(s):  
Maxim Piskunov ◽  
Alexander Ashikhmin ◽  
Nikita Khomutov ◽  
Alexandra Semyonova
2021 ◽  
Vol 13 (2) ◽  
pp. 17639-17645
Author(s):  
Derek Andrew Rosenfield ◽  
Alfred Acosta ◽  
Denise Trigilio Tavares ◽  
Cristiane Schilbach Pizzutto

The ability to inject wild animals from a distance using remote drug delivery systems (RDDS) is one of the most effective and humane practices in wildlife management.  Several factors affect the successful administration of drugs using RDDS.  For example, temperature-dependent viscosity change in aqueous (Newtonian) or water-in-oil emulsion (non-Newtonian) fluids, commonly used in tranquilizer and adjuvant-based vaccines, respectively, can potentially result in drug delivery failure.  To better understand impacts due to viscosity changes, we investigated the fluid dynamics and ballistics involved in remote drug delivery.  Our research was divided into two phases: we investigated the viscosimetric physics in the first phase to determine the fluid behavior under different temperature settings, simulating recommended storage temperature (7ºC), plus an ambient temperature (20ºC).  In the second phase of our study, we assessed the drug delivery efficiency by specialized darts, using a precision CO2 projector and a blowgun. Efficiency assessment was done by comparing the original drug volume with the actual volume injected after firing the dart into a fresh pork hide mounted on a ballistic gel.  Before testing, we configured the required minimum impact velocity for our parameters and intramuscular injection (determined as ˃ 40 m/sec).  All executed dart-deployments performed satisfactorily, despite initial concerns of potential incomplete drug delivery, however, noteworthy drug loss was observed (˃10%) associated with drug residues in syringe/dart dead space and within the transfer needle.  This could potentially result in inaccurate dosing depending on the drug used.  Furthermore, the use of a blowgun for remote drug delivery (>3m) is discouraged, especially when using specialized darts, as the required minimum dart velocity for adequate penetration is difficult to reach, in addition to a loss of precision during targeting. 


Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1300
Author(s):  
Evgenii S. Baranovskii ◽  
Vyacheslav V. Provotorov ◽  
Mikhail A. Artemov ◽  
Alexey P. Zhabko

This paper deals with a 3D mathematical model for the non-isothermal steady-state flow of an incompressible fluid with temperature-dependent viscosity in a pipeline network. Using the pressure and heat flux boundary conditions, as well as the conjugation conditions to satisfy the mass balance in interior junctions of the network, we propose the weak formulation of the nonlinear boundary value problem that arises in the framework of this model. The main result of our work is an existence theorem (in the class of weak solutions) for large data. The proof of this theorem is based on a combination of the Galerkin approximation scheme with one result from the field of topological degrees for odd mappings defined on symmetric domains.


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