45 research outputs found

    Modification of Oligomers and Reinforced Polymeric Composites by Carbon Nanotubes and Ultrasonic

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    An abridged version of the book chapter is presented in the archive. Full version on the publisher's site: https://link.springer.com/chapter/10.1007/978-3-030-26672-1_3Розглядається широке коло питань щодо розроблених напрямів модифікації епоксидних олігомерів і армованих полімерних композитів на їх основі вуглецевими нанотрубками і ультразвуком. Аналізується перспективність створення гібридних полімерних композитів функціонального призначення.This chapter analyzes the physical (in the form of ultrasound) and chemical modification of liquid polymer media and reinforced polymeric composites. The main emphasis is made on the analysis of ultrasonic cavitation processing as the most effective one for solving one of the main technological problems in the production of nanomodified polymer composites

    The formation of human populations in South and Central Asia

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    By sequencing 523 ancient humans, we show that the primary source of ancestry in modern South Asians is a prehistoric genetic gradient between people related to early hunter-gatherers of Iran and Southeast Asia. After the Indus Valley Civilization’s decline, its people mixed with individuals in the southeast to form one of the two main ancestral populations of South Asia, whose direct descendants live in southern India. Simultaneously, they mixed with descendants of Steppe pastoralists who, starting around 4000 years ago, spread via Central Asia to form the other main ancestral population. The Steppe ancestry in South Asia has the same profile as that in Bronze Age Eastern Europe, tracking a movement of people that affected both regions and that likely spread the distinctive features shared between Indo-Iranian and Balto-Slavic languages

    Active Hydraulically Interconnected Suspension. Modeling and Simulation

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    © 2017 SAE International. Rollover prevention is one of the prominent priorities in vehicle safety and handling control. A promising alternative for roll angle cancellation is the active hydraulically interconnected suspension. This paper represents the analytical model of a closed circuit active hydraulically interconnected suspension system followed by the simulation. Passive hydraulically interconnected suspension systems have been widely discussed and studied up to now. This work specifically focuses on the active hydraulically interconnected suspension system. Equations of motion of the system are formalized first. The system consists of two separate subsystems that can be modeled independently and further combined for simulation. One of the two subsystems is 4 degrees of freedom half-car model which simulates vehicle lateral dynamics and vehicle roll angle response to lateral acceleration in particular. The other subsystem is active hydraulically interconnected suspension system which is responsible for active roll angle reduction. The subsystems are coupled via hydraulics-to-mechanical boundary condition. The methodology used is based on obtaining the equations of motion for the hydraulically interconnected suspension system as well as the half-car model. Standard Lagrange method is used for the half-car model. Hydraulic impedance method and the Kirchhoff's laws for hydraulics are used for the hydraulic circuit. Under a certain simplification, the state-space model of the whole system can be obtained with all states measurable. In simulation part, the system response is examined under a number of typical input tests including NHTSA J-turn maneuver and NHSTA fishhook maneuver. The ability of the active system in roll angle reduction is compared with the conventional car suspension and passive hydraulically interconnected suspension system
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