Comparative assessment of vehicle anti-lock braking system operation using friction brake mechanisms and e-machine in the vehicle with electric drive of traction wheels

Study of the braking process of the vehicle with an electric machine in the traction wheels drive equipped with an anti-lock braking system (ABS), where the actuators are the electric machine and friction brake mechanisms, is a relevant task. This is related to the worldwide trending increase in the share of production of vehicles with an electric machine within the transmission. In this paper, the "traditional" ABS and two systems with different variants of usage of the electric machine and friction brake mechanisms as actuators are compared: 1. The electric machine fulfills the function of the wheel slip regulator; the friction brake mechanisms maintain constant pressure in the brake line, which depends on the tyre-road friction coefficient. 2. The friction brake mechanisms fulfill the function of the wheel slip regulator; the electric machine maintains the set brake torque. According to the study results, usage of the combined actuator system within the ABS allows reducing the braking distance significantly, raising the vehicle deceleration value and improving the driver's and passengers' comfort during braking

New Insight into the Deep Structure of Antarctic Peninsula Continental Margin by Methods of 2d Gravity/Magnetic Modelling and 3d Seismic Tomography

The Antarctic Peninsula, one of several terrains of Western Antarctica, is a Mesozoic magmatic arc at the southeastern Pacific margin. In order to investigate the structure of the crust and uppermost mantle of Antarctic Peninsula continental margin we have developed joint geophysical models by 2D gravity and magnetic modelling along two most representative and lengthy seismic refraction lines, acquired by Polish Academy of Sciences in 1980-1990th

High-pressure phase and transition phenomena in ammonia borane NH3BH3 from X-ray diffraction, Landau theory, and ab initio calculations

Structural evolution of a prospective hydrogen storage material, ammonia borane NH3BH3, has been studied at high pressures up to 12 GPa and at low temperatures by synchrotron powder diffraction. At 293 K and above 1.1 GPa a disordered I4mm structure reversibly transforms into a new ordered phase. Its Cmc21 structure was solved from the diffraction data, the positions of N and B atoms and the orientation of NH3 and BH3 groups were finally assigned with the help of density functional theory calculations. Group-theoretical analysis identifies a single two-component order parameter, combining ordering and atomic displacement mechanisms, which link an orientationally disordered parent phase I4mm with ordered distorted Cmc21, Pmn21 and P21 structures. We propose a generic phase diagram for NH3BH3, mapping three experimentally found and one predicted (P21) phases as a function of temperature and pressure, along with the evolution of the corresponding structural distortions. Ammonia borane belongs to the class of improper ferroelastics and we show that both temperature- and pressure-induced phase transitions can be driven to be of the second order. The role of N-H...H-B dihydrogen bonds and other intermolecular interactions in the stability of NH3BH3 polymorphs is examined.Comment: 23 pages, 7 figure

Creation of operation algorithms for combined operation of anti-lock braking system (ABS) and electric machine included in the combined power plant

The paper considers the Anti-lock Braking System (ABS) operation algorithm, which enables the implementation of hybrid braking, i.e. the braking process combining friction brake mechanisms and e-machine (electric machine), which operates in the energy recovery mode. The provided materials focus only on the rectilinear motion of the vehicle. That the ABS task consists in the maintenance of the target wheel slip ratio, which depends on the tyre-road adhesion coefficient. The tyre-road adhesion coefficient was defined based on the vehicle deceleration. In the course of calculated studies, the following operation algorithm of hybrid braking was determined. At adhesion coefficient ≤0.1, driving axle braking occurs only due to the e-machine operating in the energy recovery mode. In other cases, depending on adhesion coefficient, the e-machine provides the brake torque, which changes from 35 to 100% of the maximum available brake torque. Virtual tests showed that values of the wheel slip ratio are close to the required ones. Thus, this algorithm makes it possible to implement hybrid braking by means of the two sources creating the brake torque

НОВЫЕ ПАЛЕОМАГНИТНЫЕ ДАННЫЕ ПО СИЛУРИЙСКИМ И ДЕВОНСКИМ ОСАДОЧНЫМ ПОРОДАМ ПОДОЛИИ (ЮГО-ЗАПАДНАЯ УКРАИНА) И КИНЕМАТИКА ВОСТОЧНО-ЕВРОПЕЙСКОЙ ПЛАТФОРМЫ В СРЕДНЕМ ПАЛЕОЗОЕ

Paleomagnetic data are the priority source of information for global paleotectonic reconstructions representing horizontal movements of the crustal blocks. Upon receipt of new paleomagnetic data, kinematic models of the East European platform in the Paleozoic are regularly revised and improved. The article presents results of the paleomagnetic study of sedimentary gray-colored and red beds of the Silurian and Lower Devonian sequences located in the Dniester river basin, Podolia region, SW Ukraine. The study covered 17 outcrops that are stratigraphically correlated with the Wenlock, Ludlow, Pridoli states of the Sillurian and the Lochkovian stage of the Devon. Over 400 samples of grey limestone, argillite, dolomite, red limestone and sandstone were analyzed, and two components of natural remnant magnetization (NRM) were revealed. The first component with SSW declination and negative inclination is revealed in the majority of the samples during AF- and T-magnetic cleaning. Its pole positions, that are calculated separately for each series, are trending to the Permian segment of the apparent polar wander path (APWP) published by Torsvik et al. [2012] for Baltica / Stable Europe. Considering its chemical origin, this NRM component is related to formation of authigenic minerals due to rock remagnetization. The second component is revealed only in some samples taken from the red beds (during thermal demagnetization in the range of unblocking temperatures from 590 to 690 °С) and in few samples of grey limestone (in AF fields from 30 to 70 mT or in the range of unblocking temperatures from 300 to 460 °С). This component has SW declination and positive inclination, goes to the origin of coordinates of the diagrams, and has all the indicators of primary magnetization of sediments. Calculated positions of the poles (0 ºS and 329 ºE for grey limestone of the Tiverskaya series, 2.3 °S and 338.4 °E for red beds of the Dniestrovskaya series, etc.) are well correlated with the Devonian segments of APWP for Baltica / Stable Europe. The same is true for the Silurian poles. The new results suggest that in the Ludlow, the East European platform was located at the near-equatorial latitudes of the Southern Hemisphere, and in the Pridoli, it moved to the north towards the equatorial latitudes of the Southern Hemisphere. Later on, the drifting mode was changed, and the platform moved to the south. In the Lochkovian, its position was stabilized at the equatorial latitudes of the Southern Hemisphere. Drifting of the platform can be described by counterclockwise rotation by 16° around the Euler pole (Φ=34 °S, Λ=247 °E). Палеомагнитным данным отводится приоритетная роль при глобальных палеотектонических реконструкциях, которые отображают горизонтальные перемещения отдельных блоков земной коры. Построенные на их основе кинематические модели миграции Восточно-Европейской платформы (ВЕП) в палеозое по мере поступления нового фактического материала постоянно уточняются. В работе приводятся результаты палеомагнитных исследований осадочных сероцветных и красноцветных отложений силура и нижнего девона юго-запада Украины (район Подолии, бассейн реки Днестр). Для палеомагнитных исследований были выбраны 17 обнажений, которые стратиграфически сопоставимы с венлокским, лудловским, пржидольским отделами силура и лохковским ярусом девона и представлены сероцветными известняками, аргиллитами, доломитами и красноцветными известняками и песчаниками. В результате исследований коллекции более 400 образцов были выделены две компоненты естественной остаточной намагниченности (ЕОН). Первая выделяется на большинстве образцов при Н- и Т-чистках, имеет юг-юго-западное склонение и отрицательное наклонение. Соответствующие ей палеомагнитные полюсы, рассчитанные для каждой серии отдельно, тяготеют к пермскому сегменту сегмента траектории кажущейся миграции полюса (ТКМП) для Балтики / стабильной Европы [Torsvik et al., 2012]. Эта компонента химической природы связана с образованием аутигенных минералов при перемагничивании пород. Другая компонента, выделяемая в только в отдельных образцах красноцветов (при температурной чистке в диапазоне деблокирующих температур 590–690 °С) и в единичных образцах сероцветов (в переменных полях 30–70 мТл либо в диапазоне деблокирующих температур 300–460 °С), имеет юго-западное склонение и положительное наклонение, идет к началу координат диаграмм и характеризуется всеми признаками первичной намагниченности. Рассчитанные палеомагнитные полюса (0 °S, 329 °E для сероцветов тиверской серии, 2.3 °S, 338.4 °E для красноцветов днестровской серии и др.) хорошо согласуются с нижнедевонским фрагментом ТКМП для Балтики / стабильной Европы. Это же справедливо и для силурийских полюсов. Согласно новым результатам, в лудлове ВЕП располагалась в приэкваториальных широтах Южного полушария, в пржидольское время перемещалась к северу в экваториальные широты Южного полушария. Далее характер дрейфа изменяется – происходит перемещение уже в южном направлении, и в лохковское время положение ВЕП стабилизируется в приэкваториальных широтах Южного полушария. Характер дрейфа платформы можно описать поворотом против часовой стрелки на 16º вокруг полюса Эйлера, с координатами Φ=34 °S, Λ=247 °E.

Microevolution of tick-borne encephalitis virus in course of host alternation

AbstractTwo tick-borne encephalitis (TBE) virus variants were studied: mouse brain-adapted strain EK-328 and its derivate adapted to Hyalomma marginatum ticks. The tick-adapted virus exhibited small-plaque phenotype and slower replication in PEK cells, higher yield in ticks, decreased neuroinvasiveness in mice, increased binding to heparin-sepharose. A total of 15 nucleotide substitutions distinguished genomes of these variants, six substitutions resulted in protein sequence alterations, and two were in 5′NTR. Two amino acid substitutions in E protein were responsible for the observed phenotypic differences. Data obtained during reverse passaging of the tick-adapted virus in vivo and in vitro suggest that TBE virus exists as a heterogeneous population that contains virus variants most adapted to reproduction in either ticks or mammals. Host switch results in a change in the ratio of these variants in the population. Plaque purification of the tick-adapted virus resulted in the prompt emergence of new mutants with different virulence for mammals

The peculiarities of cross-correlation between two secondary precursors - radon and magnetic field variations, induced by stress transfer changes

A model of precursor manifestation mechanisms, stimulated by tectonic activity and some peculiarities of observer strategy, whose main task is the effective measurement of precursors in the spatial area of their occurrence on the Earth's daylight, are considered. In particular, the applicability of Dobrovolsky's approximation is analyzed, when an unperturbed medium (characterized by the simple shear state) and the area of tectonic activity (local inhomogeneity caused by the change only of shear modulus) are linearly elastic, and perturbation, in particular, surface displacement is calculated as a difference of the solutions of two independent static problems of the theory of elasticity with the same boundary condition on the surface. Within the framework of this approximation a formula for the spatial distribution (of first component) of magnetic field variations caused by piezomagnetic effect in the case of perturbed regular medium, which is in simple shear state is derived. Cogent arguments in favor of linear dependence between the radon spatial distribution and conditional deformation are obtained. Changes in magnetic field strength and radon concentrations were measured along a tectonomagnetic profile of the total length of 11 km in the surroundings of the "Academician Vernadsky" Station on the Antarctic Peninsula (W 64{\deg}16', S 65{\deg}15'). Results showed a positive correlation between the annual surface radon concentration and annual changes of magnetic field relative to a base point, and also the good coincidence with theoretical calculation.Comment: 27 pages, 11 figures, 3 tables (a substantially revised and extended edition; v3 -- some analysis of recent publications added