1
|
Rusen E, Brîncoveanu O, Dincă V, Toader G, Diacon A, Dinescu MA, Mocanu A. Surface pre-treatment of aluminum alloy for mechanical improvement of adhesive bonding by maple-assisted pulsed laser evaporation technique. RSC Adv 2024; 14:22627-22641. [PMID: 39027041 PMCID: PMC11255560 DOI: 10.1039/d4ra03187c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 07/12/2024] [Indexed: 07/20/2024] Open
Abstract
Adhesive joints are widely used for structural bonding in various industrial sectors. The performance of bonded joints is commonly attributed to the cleanliness of the substrate and the pre-treatment of the surfaces to be bonded. In this study, the Matrix Assisted Pulsed Laser Evaporation (MAPLE) deposition technique was used for surface modification of aluminum (Al) plates by the deposition of poly(propylene glycol) bis(2-aminopropyl ether) (PPG-NH2) of different number average molecular weights (Mn) of 400 g mol-1, 2000 g mol-1, and 4000 g mol-1, respectively. Fourier-transformed infrared spectroscopy (FT-IR) analysis indicated the characteristic peaks for the deposited layers of PPG-NH2 of different molecular weights in all cases while scanning electron microscopy (SEM) revealed continuous layers on the surface of Al plates. In order to demonstrate alterations in the wettability of Al substrates, a crucial aspect in surface treatment and adhesive bonding, measurements of contact angles, surface free energies (SFE), and adhesion work (W a) were conducted. The tensile strength measurements were performed using the lap-joint test after applying the commercial silyl-based polymer adhesive Bison Max Repair Extreme Adhesive®. It was evidenced that at higher values of the SFE and W a, the tensile strength was almost 3 times higher for PPG-NH2 with Mn = 4000 g mol-1 compared with the untreated Al sample. This study provides valuable insights into the successful application of the MAPLE technique as a pre-treatment method for reinforcing adhesive bonding of Al plates, which can lead to improved mechanical performance in various industrial applications.
Collapse
Affiliation(s)
- Edina Rusen
- University Politehnica of Bucharest 1-7 Gh Polizu, Polizu Campus, Sector 1 RO-011061 Bucharest Romania
| | - Oana Brîncoveanu
- National Institute for Research and Development in Microtechnologies - IMT Bucharest 126A Erou Iancu Nicolae Street 077190 Bucharest Romania
- Research Institute of the University of Bucharest, ICUB Bucharest Soseaua Panduri, nr. 90, Sector 5 050663 Bucureşti Romania
| | - Valentina Dincă
- National Institute for Laser, Plasma and Radiation Physics 409 Atomiştilor Street 077125 Măgurele Ilfov Romania
| | - Gabriela Toader
- Military Technical Academy "Ferdinand I" 39-49 Blvd. George Coşbuc, Sector 5 050141 Bucharest Romania
| | - Aurel Diacon
- University Politehnica of Bucharest 1-7 Gh Polizu, Polizu Campus, Sector 1 RO-011061 Bucharest Romania
- Military Technical Academy "Ferdinand I" 39-49 Blvd. George Coşbuc, Sector 5 050141 Bucharest Romania
| | - Miron Adrian Dinescu
- National Institute for Research and Development in Microtechnologies - IMT Bucharest 126A Erou Iancu Nicolae Street 077190 Bucharest Romania
| | - Alexandra Mocanu
- University Politehnica of Bucharest 1-7 Gh Polizu, Polizu Campus, Sector 1 RO-011061 Bucharest Romania
- National Institute for Research and Development in Microtechnologies - IMT Bucharest 126A Erou Iancu Nicolae Street 077190 Bucharest Romania
| |
Collapse
|
2
|
Zhang J, Zhang Y, Li Y, Luo M, Zhang J. Influence of Strong Shear Field on Structure and Performance of HDPE/PA6 In Situ Microfibril Composites. Polymers (Basel) 2024; 16:1032. [PMID: 38674952 PMCID: PMC11055155 DOI: 10.3390/polym16081032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
As one of the most widely applied general-purpose plastics, high-density polyethylene (HDPE) exhibits good comprehensive performance. However, mechanical strength limits its wider application. In this work, we introduced the engineering plastic PA6 as a dispersed phase to modify the HDPE matrix and applied multiple shears generated by vibration to the polymer melt during the packing stage of injection molding. SEM, 2D-WXRD and 2D-SAXS were used to characterize the morphology and structure of the samples. The results show that under the effect of a strong shear field, the dispersed phase in the composites can form in situ microfibers and numerous high-strength shish-kebab and hybrid shish-kebab structures are formed. Additionally, the distribution of fibers and high-strength oriented structures in the composites expands to the core region with the increase in vibration times. As a result, the tensile strength, tensile modulus and surface hardness of VIM-6 can reach a high level of 66.5 MPa, 981.4 MPa and 72, respectively. Therefore, a high-performance HDPE product is successfully prepared in this study, which is of great importance for expanding the application range of HDPE products.
Collapse
Affiliation(s)
| | | | | | | | - Jie Zhang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China; (J.Z.); (Y.Z.); (Y.L.); (M.L.)
| |
Collapse
|
3
|
Jeang WJ, Bochenek MA, Bose S, Zhao Y, Wong BM, Yang J, Jiang AL, Langer R, Anderson DG. Silicone cryogel skeletons enhance the survival and mechanical integrity of hydrogel-encapsulated cell therapies. SCIENCE ADVANCES 2024; 10:eadk5949. [PMID: 38578991 PMCID: PMC10997197 DOI: 10.1126/sciadv.adk5949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 03/01/2024] [Indexed: 04/07/2024]
Abstract
The transplantation of engineered cells that secrete therapeutic proteins presents a promising method for addressing a range of chronic diseases. However, hydrogels used to encase and protect non-autologous cells from immune rejection often suffer from poor mechanical properties, insufficient oxygenation, and fibrotic encapsulation. Here, we introduce a composite encapsulation system comprising an oxygen-permeable silicone cryogel skeleton, a hydrogel matrix, and a fibrosis-resistant polymer coating. Cryogel skeletons enhance the fracture toughness of conventional alginate hydrogels by 23-fold and oxygen diffusion by 2.8-fold, effectively mitigating both implant fracture and hypoxia of encapsulated cells. Composite implants containing xenogeneic cells engineered to secrete erythropoietin significantly outperform unsupported alginate implants in therapeutic delivery over 8 weeks in immunocompetent mice. By improving mechanical resiliency and sustaining denser cell populations, silicone cryogel skeletons enable more durable and miniaturized therapeutic implants.
Collapse
Affiliation(s)
- William J. Jeang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- David H Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Matthew A. Bochenek
- David H Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Suman Bose
- David H Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Scottsdale, AZ 85259, USA
| | - Yichao Zhao
- David H Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Bryan M. Wong
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jiawei Yang
- David H Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Mechanical and Materials Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Alexis L. Jiang
- Department of Computer Science, Wellesley College, Wellesley, MA 02481, USA
| | - Robert Langer
- David H Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Harvard-MIT Program in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Daniel G. Anderson
- David H Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Harvard-MIT Program in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
4
|
Pashazadeh J, Ostadrahimi A, Baghani M, Choi E. Finite Bending of Fiber-Reinforced Visco-Hyperelastic Material: Analytical Approach and FEM. MATERIALS (BASEL, SWITZERLAND) 2023; 17:5. [PMID: 38203859 PMCID: PMC10780281 DOI: 10.3390/ma17010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/01/2023] [Accepted: 11/06/2023] [Indexed: 01/12/2024]
Abstract
This paper presents a new anisotropic visco-hyperelastic constitutive model for finite bending of an incompressible rectangular elastomeric material. The proposed approach is based on the Mooney-Rivlin anisotropic strain energy function and non-linear visco-hyperelastic method. In this study, we aim to examine the mechanical response of a reinforced viscoelastic rectangular bar with a group of fibers under bending. Anisotropic materials are typically composed of one (or more) family of reinforcing fibers embedded within a soft matrix material. This operation may lead to an enhancement in the strength and stiffness of soft materials. In addition, a finite element simulation is carried out to validate the accuracy of the analytical solution. In this research, the well-known stress relaxation test, as well as the multi-step relaxation test, are examined both analytically and numerically. The results obtained from the analytical solution are found to be in good agreement with those from the finite element method. Therefore, it can be deduced that the proposed model is competent in describing the mechanical behavior of fiber-reinforced materials when subjected to finite bending deformations.
Collapse
Affiliation(s)
- Jafar Pashazadeh
- School of Mechanical Engineering, Collage of Engineering, University of Tehran, Tehran 14155-6455, Iran;
| | - Alireza Ostadrahimi
- Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Mostafa Baghani
- School of Mechanical Engineering, Collage of Engineering, University of Tehran, Tehran 14155-6455, Iran;
| | - Eunsoo Choi
- Department of Civil and Environmental Engineering, Hongik University, Seoul 04066, Republic of Korea;
| |
Collapse
|
5
|
Lee J, Lee H, Kim N. Fiber Orientation and Strain Rate-Dependent Tensile and Compressive Behavior of Injection Molded Polyamide-6 Reinforced with 20% Short Carbon Fiber. Polymers (Basel) 2023; 15:polym15030738. [PMID: 36772039 PMCID: PMC9920516 DOI: 10.3390/polym15030738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/25/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
As the interest in short-fiber reinforced polymer (SFRP) composites manufactured by injection molding increases, predicting the failure of SFRP structures becomes important. This study aims to systemize the prediction of failure of SFRP through mechanical property evaluation considering the anisotropy and strain rate dependency. To characterize the mechanical properties of polyamide-6 reinforced with carbon fiber of a weight fraction of 20% (PA6-20CF), tensile and compressive experiments were conducted with different load-applying directions and strain rates. Additionally, the results were discussed in detail by SEM image analysis of the fracture faces of the specimen. FE simulations based on the experimental condition were constructed, and the numerical model coefficients were derived through comparison with experimental results. The coefficients obtained were verified by bending tests of the specimens manufactured from composite cross members fabricated by injection molding. Predicting under static and high strain rate conditions, small errors of about 9.6% and 9.3% were shown, respectively. As a result, it proves that explained procedures allow for better failure prediction and for contribution to the systematization of structural design.
Collapse
Affiliation(s)
| | | | - Naksoo Kim
- Correspondence: ; Tel.: +82-010-2703-8635
| |
Collapse
|
6
|
Qiao J, Zhang Q, Wu C, Wu G, Li L. Effects of Fiber Volume Fraction and Length on the Mechanical Properties of Milled Glass Fiber/Polyurea Composites. Polymers (Basel) 2022; 14:polym14153080. [PMID: 35956593 PMCID: PMC9370809 DOI: 10.3390/polym14153080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 02/04/2023] Open
Abstract
Composites of polyurea (PU) reinforced with milled glass fiber (MGf) were fabricated. The volume fraction and length of the milled glass fiber were varied to study their effects on the morphological and mechanical properties of the MGf/PU composites. The morphological attributes were characterized with scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The SEM investigations revealed a uniform distribution and arbitrary orientation of milled glass fiber in the polyurea matrix. Moreover, it seems that the composites with longer fiber exhibit better interfacial bonding. It was found from the FTIR studies that the incorporation of milled glass fiber into polyurea leads to more phase mixing and decreases the hydrogen bonding of the polyurea matrix, while having a negligible effect on the H-bond strength. The compression tests at different strain rates (0.001, 0.01, 0.1, 1, 2000 and 3000 s−1) and dynamic mechanical properties over the temperature range from −30 to 100 °C at 1 Hz were performed. Experimental results show that the compressive behavior of MGf/PU composites is nonlinear and strain-rate-dependent. Both elastic modulus and flow stress at any given strain increased with strain rate. The composites with higher fiber volume fraction and longer fiber length are more sensitive to strain rate. Furthermore, the elastic modulus, stress at 65% strain and energy absorption capability were studied, taking into account both the effect of fiber volume fraction and mean fiber length. It is noted that an increase in fiber volume fraction and fiber length leads to an increase in elastic modulus, stress at 65% strain and absorbed energy up to ~103%, 83.0% and 137.5%, respectively. The storage and loss moduli of the composites also increase with fiber volume fraction and fiber length. It can be concluded that the addition of milled glass fiber into polyurea not only improves the stiffness of the composites but also increases their energy dissipative capability.
Collapse
Affiliation(s)
- Jing Qiao
- School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; (Q.Z.); (C.W.); (G.W.)
- Correspondence: (J.Q.); (L.L.); Tel.: +86-451-86412164 (J.Q. & L.L.)
| | - Quan Zhang
- School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; (Q.Z.); (C.W.); (G.W.)
| | - Chong Wu
- School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; (Q.Z.); (C.W.); (G.W.)
| | - Gaohui Wu
- School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; (Q.Z.); (C.W.); (G.W.)
| | - Longqiu Li
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
- Correspondence: (J.Q.); (L.L.); Tel.: +86-451-86412164 (J.Q. & L.L.)
| |
Collapse
|
7
|
Beskopylny AN, Meskhi B, Stel’makh SA, Shcherban’ EM, Mailyan LR, Veremeenko A, Akopyan V, Shilov AV, Chernil’nik A, Beskopylny N. Numerical Simulation of the Bearing Capacity of Variotropic Short Concrete Beams Reinforced with Polymer Composite Reinforcing Bars. Polymers (Basel) 2022; 14:polym14153051. [PMID: 35956566 PMCID: PMC9370235 DOI: 10.3390/polym14153051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
One of the disadvantages of reinforced concrete is the large weight of structures due to the steel reinforcement. A way to overcome this issue and develop new types of reinforcing elements is by using polymer composite reinforcement, which can successfully compensate for the shortcomings of steel reinforcement. Additionally, a promising direction is the creation of variotropic (transversely isotropic) building elements. The purpose of this work was to numerically analyze improved short bending concrete elements with a variotropic structure reinforced with polymer composite rods and to determine the prospects for the further extension of the results obtained for long-span structures. Numerical models of beams of a transversally isotropic structure with various types of reinforcement have been developed in a spatially and physically nonlinear formulation in ANSYS software considering cracking and crashing. It is shown that, in combination with a stronger layer of the compressed zone of the beam, carbon composite reinforcement has advantages and provides a greater bearing capacity than glass or basalt composite. It has been proven that the use of the integral characteristics of concrete and the deflections of the elements are greater than those when using the differential characteristics of concrete along the height of the section (up to 5%). The zones of the initiation and propagation of cracks for different polymer composite reinforcements are determined. An assessment of the bearing capacity of the beam is given. A significant (up to 146%) increase in the forces in the reinforcing bars and a decrease in tensile stresses (up to 210–230%) were established during the physically non-linear operation of the concrete material. The effect of a clear redistribution of stresses is in favor of elements with a variotropic cross section in height.
Collapse
Affiliation(s)
- Alexey N. Beskopylny
- Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, Gagarin, 1, 344003 Rostov-on-Don, Russia
- Correspondence: ; Tel.: +7-8632738454
| | - Besarion Meskhi
- Department of Life Safety and Environmental Protection, Faculty of Life Safety and Environmental Engineering, Don State Technical University, Gagarin, 1, 344003 Rostov-on-Don, Russia;
| | - Sergey A. Stel’makh
- Department of Engineering Geology, Bases, and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia; (S.A.S.); (E.M.S.); (V.A.)
| | - Evgenii M. Shcherban’
- Department of Engineering Geology, Bases, and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia; (S.A.S.); (E.M.S.); (V.A.)
| | - Levon R. Mailyan
- Department of Roads, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia; (L.R.M.); (A.V.)
| | - Andrey Veremeenko
- Department of Roads, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia; (L.R.M.); (A.V.)
| | - Vladimir Akopyan
- Department of Engineering Geology, Bases, and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia; (S.A.S.); (E.M.S.); (V.A.)
| | - Aleksandr V. Shilov
- Department of Reinforced Concrete Structures, Faculty of Industrial and Civil Engineering, Don State Technical University, Gagarin, 1, 344003 Rostov-on-Don, Russia;
| | - Andrei Chernil’nik
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia;
| | - Nikita Beskopylny
- Department of Hardware and Software Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia;
| |
Collapse
|
8
|
Berladir K, Zhyhylii D, Gaponova O, Krmela J, Krmelová V, Artyukhov A. Modeling of Polymer Composite Materials Chaotically Reinforced with Spherical and Cylindrical Inclusions. Polymers (Basel) 2022; 14:2087. [PMID: 35631969 PMCID: PMC9144413 DOI: 10.3390/polym14102087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/14/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
The technical and economic efficiency of new PCMs depends on the ability to predict their performance. The problem of predicting the properties of PCMs can be solved by computer simulation by the finite element method. In this work, an experimental determination of the physical and mechanical properties of PTFE PCMs depending on the concentration of fibrous and dispersed filler was carried out. A finite element model in ANSYS APDL was built to simulate the strength and load-bearing capacity of the material with the analysis of damage accumulation. Verification of the developed computer model to predict the mechanical properties of composite materials was performed by comparing the results obtained during field and model experiments. It was found that the finite element model predicts the strength of chaotically reinforced spherical inclusions of composite materials. This is due to the smoothness of the filler surfaces and the lack of filler dissection in the model. Instead, the prediction of the strength of a finite element model of chaotically reinforced cylindrical inclusions of composite materials requires additional analysis. The matrix and the fibrous filler obviously have stress concentrators and are both subject to the difficulties of creating a reliable structural model.
Collapse
Affiliation(s)
- Kristina Berladir
- Department of Applied Materials Science and Technology of Constructional Materials, Sumy State University, 2, Rymskogo-Korsakova St., 40007 Sumy, Ukraine;
| | - Dmytro Zhyhylii
- Department of Computational Mechanics Named after Volodymyr Martsynkovskyy, Sumy State University, 2, Rymskogo-Korsakova St., 40007 Sumy, Ukraine;
| | - Oksana Gaponova
- Department of Applied Materials Science and Technology of Constructional Materials, Sumy State University, 2, Rymskogo-Korsakova St., 40007 Sumy, Ukraine;
| | - Jan Krmela
- Faculty of Mechanical Engineering, J. E. Purkyně University in Ustí nad Labem, Pasteurova 1, 400 96 Ustí nad Labem, Czech Republic;
| | - Vladimíra Krmelová
- Faculty of Industrial Technologies in Púchov, Alexander Dubček University of Trenčín, I. Krasku 491/30, 02001 Púchov, Slovakia;
| | - Artem Artyukhov
- Academic and Research Institute of Business, Economics and Management, Sumy State University, 2, Rymskogo-Korsakova St., 40007 Sumy, Ukraine;
| |
Collapse
|