Zobrazeno 1 - 10
of 100
pro vyhledávání: '"Victor A. Kovtunenko"'
Autor:
Victor A. Kovtunenko
Publikováno v:
Technologies, Vol 12, Iss 10, p 202 (2024)
The influence of particle size distribution in platinum catalysts on the aging of PEM fuel cells described by Holby–Morgan electrochemical degradation model is under investigation. The non-diffusive model simulates mechanisms of particle drop by Pt
Externí odkaz:
https://doaj.org/article/99e1f493ce8a4f7abfab2d6182899371
Publikováno v:
Applications in Engineering Science, Vol 15, Iss , Pp 100136- (2023)
A new class of unilaterally constrained problems for fully coupled poroelastic models stemming from hydraulic fracturing is introduced and studied with respect to its well-posedness. The poroelastic medium contains a fluid-driven crack, which is subj
Externí odkaz:
https://doaj.org/article/56c697fd25f84db183ec550449958230
Autor:
Victor A. Kovtunenko, Kohji Ohtsuka
Publikováno v:
Applied Mathematics in Science and Engineering, Vol 30, Iss 1, Pp 448-479 (2022)
A class of nonlinear variational problems describing incompressible fluids and solids by stationary Stokes equations given in a planar domain with a crack (infinitely thin flat plate in fluids) is considered. Based on the Fourier asymptotic analysis,
Externí odkaz:
https://doaj.org/article/a6b8b09b7e574c9e96b47553646484bf
Autor:
Victor A. Kovtunenko
Publikováno v:
Technologies, Vol 11, Iss 6, p 184 (2023)
Loss of electrochemical surface area in proton-exchange membrane is of large practical importance, since membrane degradation largely affects the durability and life of fuel cells. In this paper, the electrokinetic model developed by Holby and Morgan
Externí odkaz:
https://doaj.org/article/1a994e88a60c43abad39a121c5f36af7
Publikováno v:
Applications in Engineering Science, Vol 10, Iss , Pp 100089- (2022)
A new class of coupled poroelastic problems describing fluid-driven cracks (called fractures) subjected to non-penetration conditions between opposite crack faces (fracture walls) is considered in the incremental form. The nonlinear crack problem for
Externí odkaz:
https://doaj.org/article/01d0fe828776416bb5a352ac5ab491a9
Publikováno v:
Applications in Engineering Science, Vol 7, Iss , Pp 100060- (2021)
A class of models in the theory of elasticity is considered, where a material response between the linearized strain and the stress is assumed to be nonlinear with respect to the mean normal stress. The governing system is endowed with a mixed variat
Externí odkaz:
https://doaj.org/article/7cae68b7a704480285774b6119ee3204
Autor:
Victor A. Kovtunenko
Publikováno v:
Technologies, Vol 10, Iss 6, p 111 (2022)
Degradation of a catalyst layer in polymer electrolyte membrane fuel cells is considered, which is caused by electrochemical reactions of the platinum ion dissolution and oxide coverage. An accelerated stress test is applied, where the electric poten
Externí odkaz:
https://doaj.org/article/06a6d565033b4d5d82786339336985dd
Publikováno v:
Mathematics, Vol 10, Iss 2, p 250 (2022)
A new type of non-classical 2D contact problem formulated over non-convex admissible sets is proposed. Specifically, we suppose that a composite body in its undeformed state touches a wedge-shaped rigid obstacle at a single contact point. Composite b
Externí odkaz:
https://doaj.org/article/28488c17127b4052878c31e69be374fd
Publikováno v:
Technologies, Vol 9, Iss 4, p 80 (2021)
The durability of a platinum catalyst in a polymer electrolyte membrane fuel cell is studied at various operating conditions with respect to the different electric potential difference (called voltage) applied in accelerated stress tests. The electro
Externí odkaz:
https://doaj.org/article/c8b2d4cc07184a02a8f91a64654b7b77
Publikováno v:
Axioms, Vol 7, Iss 4, p 76 (2018)
This paper establishes the shape derivative of geometry-dependent objective functions for use in constrained variational problems. Using a Lagrangian approach, our differentiablity result is based on the theorem of Delfour⁻Zolésio on directional d
Externí odkaz:
https://doaj.org/article/1f303ebd16944e6a86abee5583b131b7