Eccentricity samples: implications on the potential and the velocity distribution

Planar and vertical epicycle frequencies and local angular velocity are related to the derivatives up to the second order of the local potential and can be used to test the shape of the potential from stellar disc samples. These samples show a more complex velocity distribution than halo stars and should provide a more realistic test. We assume an axisymmetric potential allowing a mixture of independent ellipsoidal velocity distributions, of separable or Staeckel form in cylindrical or spherical coordinates. We prove that values of local constants are not consistent with a potential separable in addition in cylindrical coordinates and with a spherically symmetric potential. The simplest potential that fits the local constants is used to show that the harmonical and non-harmonical terms of the potential are equally important. The same analysis is used to estimate the local constants. Two families of nested subsamples selected for decreasing planar and vertical eccentricities are used to borne out the relation between the mean squared planar and vertical eccentricities and the velocity dispersions of the subsamples. According to the first-order epicycle model, the radial and vertical velocity components provide accurate information on the planar and vertical epicycle frequencies. However, it is impossible to account for the asymmetric drift which introduces a systematic bias in estimation of the third constant. Under a more general model, when the asymmetric drift is taken into account, the rotation velocity dispersions together with their asymmetric drift provide the correct fit for the local angular velocity. The consistency of the results shows that this new method based on the distribution of eccentricities is worth using for kinematic stellar samples.Peer ReviewedPostprint (author's final draft

Cross reactive arrays of three-way junction sensors for steroid determination

This invention provides analyte sensitive oligonucleotide compositions for detecting and analyzing analytes in solution, including complex solutions using cross reactive arrays of analyte sensitive oligonucleotide compositions

The influence of pyrolysis type on shale oil generation and its composition (Upper layer of Aleksinac oil shale, Serbia)

The influence of pyrolysis type on shale oil generation and its composition was studied. Different methods such as Rock-Eval pyrolysis, thermogravimetric analysis (TGA) and pyrolysis in the open and closed systems were applied. Samples from the Upper layer of Aleksinac oil shale (Serbia) were used as a substrate and first time characterized in detail. The impact of kerogen content and type on the shale oil generation in different pyrolysis systems was also estimated. Majority of the analysed samples have total organic carbon content > 5 wt. % and contain oil prone kerogen types I and/or II. Therefore, they can be of particular interest for the pyrolytic processing. Thermal behavior of analysed samples obtained by TGA is in agreement with Rock-Eval parameters. Pyrolysis of oil shale in the open system gives higher yield of shale oil than pyrolysis in the closed system. The yield of hydrocarbons (HCs) in shale oil produced by open pyrolysis system corresponds to an excellent source rock potential, while HCs yield from the closed system indicates a very good source rock potential. The kerogen content has a greater impact on the shale oil generation than kerogen type in the open pyrolysis system, while kerogen type plays a more important role on generation of shale oil than the kerogen content in the closed system. The composition of obtained shale oil showed certain undesirable features, due to the relatively high contents of olefinic HCs (open system) and polar compounds (closed system), which may require further treatment to be used

VEHICLE DETECTOR BASED ON THE MAGNETIC FIELD SENSOR AND THE FIXED-THRESHOLD ALGORITHM IMPLEMENTED VIA FINITE STATE MACHINE

An automated vehicle detection process is one of the main objectives of Intelligent Transportation Systems. Different technologies, such as inductive loops, video surveillance, or acoustic sensors, are used for vehicle detection. A one of the most effective solution is based on magnetic field measurement. This detection method relies on analysis of the Earth's magnetic field changes induced by ferromagnetic materials inside a vehicle's structure. The vehicle detector composed of the magnetic field sensor used for measurements and the microcontroller with embedded detection algorithm is described in this paper. The detection algorithm compares changes in the magnetic field with a defined fixed-threshold value implemented as the finite state machine. Changing the state of the finite state machine in the defined order means that the vehicle is detected successfully. The method for determining the finite state machine parameters that depend on the fixed-threshold values and frequency of the measurements is described in detail. The vehicle detector is tested in the laboratory environment, and the results show the appropriate detection accuracy compared to the other detection algorithms in the literature

Molecular robots guided by prescriptive landscapes

Traditional robots rely for their function on computing, to store internal representations of their goals and environment and to coordinate sensing and any actuation of components required in response. Moving robotics to the single-molecule level is possible in principle, but requires facing the limited ability of individual molecules to store complex information and programs. One strategy to overcome this problem is to use systems that can obtain complex behaviour from the interaction of simple robots with their environment. A first step in this direction was the development of DNA walkers, which have developed from being non-autonomous, to being capable of directed but brief motion on one-dimensional tracks. Here we demonstrate that previously developed random walkers—so-called molecular spiders that comprise a streptavidin molecule as an inert ‘body’ and three deoxyribozymes as catalytic ‘legs’—show elementary robotic behaviour when interacting with a precisely defined environment. Single-molecule microscopy observations confirm that such walkers achieve directional movement by sensing and modifying tracks of substrate molecules laid out on a two-dimensional DNA origami landscape. When using appropriately designed DNA origami, the molecular spiders autonomously carry out sequences of actions such as ‘start’, ‘follow’, ‘turn’ and ‘stop’. We anticipate that this strategy will result in more complex robotic behaviour at the molecular level if additional control mechanisms are incorporated. One example might be interactions between multiple molecular robots leading to collective behaviour; another might be the ability to read and transform secondary cues on the DNA origami landscape as a means of implementing Turing-universal algorithmic behaviour

Recycling lithium-ion battery

Lithium-ion battery (LIB) applications in consumer electronics and hybrid and electric vehicles are rapidly growing, resulting in boosting resources demand, including cobalt and lithium. So recycling of batteries will be a necessity, not only to decline the consumption of energy, but also to relieve the shortage of rare resources and eliminate the pollution of hazardous components, toward sustainable industries related to consumer electronics and hybrid and еlectric vehicles. Analysing recycling processes of spent LIBs, it introduce the structure and components of the batteries, and summarize all available single contacts in batch mode operation, including pretreatment, secondary treatment, and deep recovery. Additionally, many problems and prospect оf the current recycling processes will be presented and analyzed. It is hoped that this effort would stimulate further interest in spent LIBs recycling and in the appreciation of its benefits

MAINTENANCE OF HYBRID VEHICLES

This paper at the begining presents the basic concepts of the different conceptual solutions for hybrid and electric vehicles, primarily in terms of their transmissions. From now on, there are certain observations concerning the reliability of these vehicles, taking into account that this area has not been explored to the extent as it is the case with conventional vehicles (with IC engine). With the development of modern diagnostic methods, a special place takes telediagnostic, as an area that offers huge advantages in quality and timely diagnosis of all processes on hybrid and electric vehicles and provides excellent input parameters to optimize the maintenance system. Finally, a serious approach to the optimization of the maintenance system of modern hybrid and electric vehicles could not be imagined without the combination of "soft" computing, i.e. fuzzy logic, classical reliability theory vehicles and newly developed diagnostic methods. This approach of the system of maintenance increases the quality of the exploitation, increases availability and reduces the overall lifecycle costs of hybrid and electric vehicles

Orbital eccentricities as indicators of stellar populations: a kinematical analysis of the local disc from GAIA DR2 catalogue

Aims. Based on a local sample from Gaia DR2 catalogue composed of 74 339 stars, we are able to derive more accurate kinematic statistics defining the local stellar populations and classify the stars in terms of their planar and vertical orbital eccentricities. Methods. Firstly, we carried out a kinematical characterisation of stellar populations from a tested mixture model that fits the trivariate velocity cumulants up to the fourth order, maximises the entropy of the mixture probability, and minimises the ¿2 error. We then proposed several approaches to classifying the stars according to the population they are most likely to belong to. None of these approaches provided a definitive solution due to the overlapping of the partial distributions. Finally, by using the epicycle approximation, we transformed the three-dimensional velocity probability space into a two-dimensional diagram. In one direction, the information of the two planar velocity components is picked up by the planar eccentricity. In the other direction, the vertical eccentricity does the same with the vertical velocity component. However, in the vertical direction, the epicycle approximation is not valid and it is replaced by a biquadratic approximation. Results. In the eccentricity diagram, the region of maximum probability for a population is approximately delimited by straight line. We characterise three local kinematic populations: thin disc, thick disc (composed of two subpopulations: canonical thick disc and metal-weak thick disc), and kinematical halo (metal-rich thick-disc plus chemical halo). The Gaia DR2 sample allows us to estimate small mean radial differential motion of 5 ± 2 km s-1 between the thin and thick discs, and of 9 ± 3 km s-1 between both thick-disc subpopulations, as well as between the disc and the kinematical halo. All disc populations and subpopulations have significant vertex deviations. Conclusions. The classification of the stars from the eccentricity diagram resolves the problem of overlapping velocity distributions by producing a segregation that is more net, along with a more precise kinematical characterisation of populations.Peer ReviewedPostprint (author's final draft

Orbital eccentricities as indicators of stellar populations. II. Vertical velocity distribution from the Gaia DR2 catalogue

Context. In previous work, we showed how the planar and vertical eccentricities of disc stars, e and e' , could be used as indicators of the stars’ kinematic populations. For a local stellar sample drawn from the Gaia DR2 catalogue, these populations were represented geometrically in the eccentricity diagram, e'² vs e² , approximately separated by straight lines. Aims. In the current work, we propose a new relationship between the star’s perpendicular velocity and its vertical eccentricity, allowing for a reevaluation of the critical vertical eccentricity and maximum height, z_max, specific to each population component. Methods. We approximated the local potential function to be consistent with the actual shape of the curve that relates the maximum vertical speed of a star and its maximum height. The curve corresponds to a non-linear restoring vertical force, where the stiffness decreases with an increase in the maximum height. The constants involved in this fitting, together with the population velocity dispersions, determine the specific region for each population in the eccentricity diagram. Results. The new classification determines 88% of the sample is made up of thin disc stars and 9% of thick disc stars, whereby 3% of the stars have been relabelled, by providing thinner thin and thick discs. Nested thin disc subsamples allow us to estimate Strömberg’s asymmetric drift equation, leading to a heliocentric velocity of the circular orbit of V_c ˜ -12.9 km s -1 , an absolute rotation velocity of T_c ˜ 227 km s -1 , and a rotation component of the Galactocentric velocity of the Sun at T_¿ ˜ 240 km s -1 . Conclusions. The thin disc stars of our local sample are characterised based on values 0 = e = 0.32, 0 = e' = 0.09, and z_max = 0.7 kpc. Disc stars satisfy 0 = e = 0.44, 0 = e' = 0.18, z_max = 1.5 kpc. The maximum vertical peculiar velocity for disc stars is found to be w_0 = 115 km s -1 . The assumed potential provides a stellar density of the disc vanishing at z_0 = 1.8 kpc. The approximate behaviour in the local disc is that a small decrease in the stiffness is associated with a relative decrease in the limiting velocity, which produces a thinner disc and a loss of stars in the local cylinder, both in a similar proportion to the limiting velocity.Peer ReviewedPostprint (author's final draft