17 results match your criteria: "Saint Petersburg State Marine Technical University[Affiliation]"
Materials (Basel)
December 2024
Laboratory of Metals and Alloys Under Extreme Impacts, Ufa University of Science and Technology, 32 Zaki Validi str., Ufa 450076, Russia.
This study investigates the dislocation density in ceramics processed by severe plastic deformation at room and elevated temperatures via high-pressure torsion (HPT) for various numbers of turns and shear strains. Ceramics, characterized by ionic or covalent bonding, typically exhibit brittleness due to limited dislocation activity. However, HPT enables significant microstructural transformations in ceramics including dislocation nucleation and accumulation.
View Article and Find Full Text PDFPolymers (Basel)
September 2024
Institute of Robotics and Intelligent Systems, Saint-Petersburg State Marine Technical University, Lotsmanskaya Str., 3, 190121 Saint-Petersburg, Russia.
Edible films based on biopolymers are used to protect food from adverse environmental factors. However, their ample use may be hindered by some challenges to their mechanical and antimicrobial properties. Despite this, in most cases, increasing their mechanical properties and antibacterial activity remains a relevant challenge.
View Article and Find Full Text PDFMaterials (Basel)
July 2024
Institute of Laser and Welding Technologies, Saint Petersburg State Marine Technical University, Lotsmanskaya Str. 3, Saint Petersburg 190121, Russia.
The results of experimental studies in the manufacture of components of the supporting structure of the first wall panel, carried out as part of the manufacture of a model of the International Thermonuclear Experimental Reactor (ITER) using laser welding technology, are presented. The influence of laser welding modes on the quality of formation, microstructure characteristics, and mechanical properties of a welded joint made of 10 mm thick 316L steel was studied. A coaxial nozzle was designed and manufactured to protect the weld pool with a curved trajectory.
View Article and Find Full Text PDFBiomimetics (Basel)
April 2024
Institute of Hydrodynamics and Control Processes, Saint-Petersburg State Marine Technical University, 190121 Sankt-Petersburg, Russia.
Soft robotics is closely related to embodied intelligence in the joint exploration of the means to achieve more natural and effective robotic behaviors via physical forms and intelligent interactions. Embodied intelligence emphasizes that intelligence is affected by the synergy of the brain, body, and environment, focusing on the interaction between agents and the environment. Under this framework, the design and control strategies of soft robotics depend on their physical forms and material properties, as well as algorithms and data processing, which enable them to interact with the environment in a natural and adaptable manner.
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May 2023
Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jl. Grafika No. 2, Yogyakarta 55281, Indonesia.
Nowadays, the hybridization of natural and glass fiber has promised several advantages as a green composite. Nevertheless, their different characteristics lead to poor mechanical bonding. In this work, agel fiber and glass fiber was used as reinforcements, and activated carbon filler was added to the polymer matrix of a hybrid composite to modify its characteristics and mechanical properties.
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June 2023
Center for Materials Technologies, Skolkovo Institute of Science and Technology, 30, Bld. 1 Bolshoy Boulevard, 121205 Moscow, Russia.
Dental implants are thought to be implanted for life, but throughout their lifespan, they function in aggressive oral environment, resulting in corrosion of the material itself as well as possible inflammation of adjacent tissues. Therefore, materials and oral products for people with metallic intraoral appliances must be chosen carefully. The purpose of this study was to investigate the corrosion behavior of common titanium and cobalt-chromium alloys in interaction with various dry mouth products using electrochemical impedance spectroscopy (EIS).
View Article and Find Full Text PDFLangmuir
April 2023
National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050, Russia.
This paper presents the results of mathematical modeling of the evaporation of a single water drop from the surface of a copper substrate using a new model, which does not require special experiments to close the system of equations and the corresponding boundary conditions with empirical constants. On the basis of the results of mathematical modeling, it was found that convective currents that occur in a small water drop (≤1 mm in diameter) do not significantly affect the characteristics or conditions of heat and mass transfer processes occurring in a liquid drop heated on a copper substrate. The results of numerical simulation showed that during the initial period of droplet heating, the latter undergoes a rapid transformation of the flow field.
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February 2023
Center for Materials Technologies, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia.
The efficiency of electronic microchip-based devices increases with advancements in technology, while their size decreases. This miniaturization leads to significant overheating of various electronic components, such as power transistors, processors, and power diodes, leading to a reduction in their lifespan and reliability. To address this issue, researchers are exploring the use of materials that offer efficient heat dissipation.
View Article and Find Full Text PDFHeliyon
November 2022
Skolkovo Institute of Science and Technology, 30, Bolshoy Blvd, Moscow 121205, Russia.
Diamond is a form of carbon that has been attracting attention for hundreds of years, owing to its physical and chemical properties of hardness, thermal conductivity, chemical inertness, and transparency. Labor and the long-term impact of a diverse workforce, is one of the most important factors in diamond mining and production and must be considered when assessing economic benefits. In the present study, we examined the labor input required to obtain one carat of diamond, via three methods: open-cast mining, high-pressure high-temperature synthesis and 2.
View Article and Find Full Text PDFPolymers (Basel)
August 2022
Lavrentyev Institute of Hydrodynamics, Pr. Lavrentyeva 15, 630090 Novosibirsk, Russia.
The concept of representative directions allows for automatic generation of multi-axial constitutive equations, starting from simplified uni-axial material models. In this paper, a modification of the concept is considered suitable for the analysis of fibrous polymeric materials, which are anisotropic in the as-received state. The modification of the concept incorporates an orientation probability density function (OPDF), which explicitly accounts for the material anisotropy.
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August 2022
Research Department, Saint-Petersburg State Marine Technical University, Lotsmanskaya 3, 190121 Saint-Petersburg, Russia.
In the presented article a generalization of Newton's formula for the shear stress in a fluid is carried out by giving it a power-law form. After the introduction of the corresponding strain rate tensor, a generalization is made to the spatial case of flow and the rheological relation is presented in tensor form. Depending on the power value in this rheological ratio, one can come either to a description of a laminar flow regime (in the form of Navier-Stokes equations), or to a description of the flow in turbulent regime.
View Article and Find Full Text PDFFront Robot AI
April 2022
Institute of Hydrodynamics and Control Processes, Saint-Petersburg State Marine Technical University, Saint Petersburg, Russia.
The soft organisms in nature have always been a source of inspiration for the design of soft arms and this paper draws inspiration from the octopus's tentacle, aiming at a soft robot for moving flexibly in three-dimensional space. In the paper, combined with the characteristics of an octopus's tentacle, a cable-driven soft arm is designed and fabricated, which can motion flexibly in three-dimensional space. Based on the TensorFlow framework, a data-driven model is established, and the data-driven model is trained using deep reinforcement learning strategy to realize posture control of a single soft arm.
View Article and Find Full Text PDFBiomed Mater
April 2022
Skolkovo Institute of Science and Technology, 30, bld. 1 Bolshoy Boulevard, Moscow 121205, Russia.
Due to many negative and undesirable side effects from the use of permanent implants, the development of temporary implants based on biocompatible and biodegradable materials is a promising area of modern medicine. In the presented study, we have investigated complex-shaped iron-silicon (Fe-Si) scaffolds that can be used as potential biodegradable framework structures for solid implants for bone grafting. Since iron and silicon are biocompatible materials, and their alloy should also have biocompatibility.
View Article and Find Full Text PDFMaterials (Basel)
February 2022
World-Class Research Center "Advanced Digital Technologies", Saint Petersburg State Marine Technical University, 190121 Saint Petersburg, Russia.
Copper-based composites strengthened with fullerene soot nanoparticles of 20-30 nm size in concentration up to 23 vol.% were prepared via two methods: mechanical mixing and molecular level mixing. The dependence of thermal conductivity on the carbon concentration was studied.
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January 2022
Department of Materials Science and Welding, Kazan National Research Technical University Named after A.N. Tupolev-KAI (KNRTU-KAI), 420111 Kazan, Russia.
The results of experimental studies of repair of the supporting structure components made of 316L steel multi-pass laser cladding with filler wire are presented. The influence of the wobbling mode parameters, welding speed, and laser power on the formation of the deposited metal during multi-pass laser cladding with filler wire of 316L steel samples into a narrow slot groove, 6 mm deep and 3 mm wide, are shown. Non-destructive testing, metallographic studies, and mechanical tests of the deposited metal before and after heat treatment (2 h at 450 °C) were carried out.
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July 2021
Institute of Laser and Welding Technology, Saint Petersburg State Marine Technical University, 190121 St. Petersburg, Russia.
The work is devoted to the development of a model for calculating transient quasiperiodic temperature fields arising in the direct deposition process of thin walls with various configurations. The model allows calculating the temperature field, thermal cycles, temperature gradients, and the cooling rate in the wall during the direct deposition process at any time. The temperature field in the deposited wall is determined based on the analytical solution of the non-stationary heat conduction equation for a moving heat source, taking into account heat transfer to the environment.
View Article and Find Full Text PDFBioinspir Biomim
June 2021
Institute of Hydrodynamics and Control Processes, Saint-Petersburg State Marine Technical University, Russia.
In order to increase the compatibility between underwater robots and the underwater environment and inspired by the coconut octopus's underwater bipedal walking, a method was proposed for bipedal walking for an underwater soft robot based on a spring-loaded inverted pendulum (SLIP) model. Using the characteristics of octopus tentacles rolling on the ground, a wrist arm was designed using the cable-driven method, and an underwater SLIP bipedal walking model was established, which makes an underwater soft robot more suitable for moving on uneven ground. An underwater bipedal walking soft robot based on coconut octopus was then designed, and a machine vision algorithm was used to extract the motion information for analysis.
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