Dynamics and configurations of galaxy triplets

The purpose is to infer the probable dynamical states of galaxy triplets by the observed data on their configurations. Two methods are proposed for describing the distributions of the triplet configuration parameters characterizing a tendency to alignment and hierarchy: (1) obtaining a representative sample of configurations and determining its statistical parameters (moments and percentages); and (2) dividing the region of possible configurations of triple systems (Agekian and Anosova, 1967) into a set of segments and finding the probabilities for the configurations to find themselves in each of them. Both these methods allow representation of the data by numerical simulations as well as observations. The effect of projection was studied. It rather overestimates the alignment and hierarchy of the triple systems. Among the parameters of interest there are found some parameters that are least sensitive to projection effects. The samples consist of simulated galaxy triplets (with hidden mass) as well as of 46 probably physical triple galaxies (Karachentseva et al., 1979). The observed triples as well as numerical models show a tendency to alignment. The triple galaxies do not show any tendency to hierarchy (formation of the temporary binaries), but this tendency may be present for simulated triplets without significant dark matter. The significant hidden mass (of order ten times the total mass of a triplet) decreases the probability of forming a binary and so weakens the hierarchy. Small galaxy groups consisting of 3 to 7 members are probably the most prevalent types of galaxy aggregate (Gorbatsky, 1987). Galaxy triplets are the simplest groups, but dynamically nontrivial ones

PRINCIPLES OF ADEQUACY CRITERIA FORMULATION IN HUMAN MOTION ANALYSIS

Introduction. Number of parameters of an anthropomorphic model (AM), which simulates real human motion, can achieve the value of one hundred and even more than that. This makes obvious the necessity of adequacy criteria formulation. Optimal value of such criteria should indicate structural and parametric adjustment of AM to certain real human motion. Modelling of human motion with employment of mechanical-mathematical apparatus of system of body motion equations implies a significant number of problem parameters [1] required for description of the structure, and components and kinematics of motion as well. Choice of these parameters values seriously depends on what experimental data is available. METHODS AND RESULTS: The base of computer model consists in a system of differential-algebraic equations of motion of a ramified kinematics chain with nonstationary constraints. In particular, as constraint equations there can serve generalized coordinates behaviour functions, obtained through video-registration data processing. Such approach allows to determine main dynamic values, including generalized forces. However, measurement errors lead to significant errors in assessed values of inter-element forces and moments and especially values of external with respect to AM ground reaction and total moment of external forces in support phase of motion. Variation of AM elements parameters, positions of joints, parameters of trajectories smoothing allows to obtain an averaged assessment of external forces values. In the report there is suggested a new approach to structural an parametrical adjustment of AM. Presence of non-stationary constraint equations allows to use some of experimental data for such constraints. For example, ground reaction force and/or external moment can be available or equal to zero during the flight phase. One of investigation result is that there have been analyzed grand circles on the horizontal bar with a following jump off the bar and four backward somersaults performed in a grouped position. The number of AM elements is widely varied. There has been investigated influence of possible errors in determination of visco-elastic properties of the bar on the analysis results for different processing procedures. CONCLUSION: The suggested approach to iterational parametric adjustment of AM on the basis of employing of constraint equations allows for complete matching of model motion characteristics with most important experimental data. Less important data are estimated in average, which corresponds to traditional structural- parametric adjustment of AM. REFERENCES: 1. Zinkovsky A.V., Sholuha V.A., Ivanov A.A. Mathematical Modelling and Computer Simulation of Biomechanical Systems, WSP, Singapore, 1997. 216p

COMPUTER SYNTHESIS AND OPTIMIZATION OF JUMPING MOTIONS VIA NONSTATIONARY CONSTRAINTS

Introduction: This report considers the results of the authors’ research on the goal-oriented computer synthesis of human motions in support and non-support phases. The main attention is paid to the synthesis of the pushing phases. In particular, an analysis is made of the results of a sequential optimization of running long jumps and acrobatic jumps. The computer modeling of complex coordination motions is based on the development of an adequate anthropomorphic model. Methods and Results: Most effective in the developed modeling system proved to be the employment of differentiated non-stationary holonomic and nonholonomic constraints equations in order to model goal-oriented motions [1]. For descriptions of additional non-stationary items in constraints equations we used parametrically controlled smooth approximation functions which allowed us to synthesize the desired motion trajectories, ground reaction force and kinetic moment increment. Due to the non-stationary nature of constraints equations, any experimental data on kinematics and/or the dynamics of real motion can fulfill their function. For the analysis of modeling results we consider estimates of interelement control motions distribution in the support phase of jumping motion. A number of anthropomorphic model (AM) elements can change with respect to the level of AM adequacy to real human motion. For example, we used a 15-element AM for modeling the support and flying phases of the running long jump. Analysis of synthesized inter-element control moments values showed that the most significant influence on the value of the ground reaction and, therefore, on the pushingoff velocity was the motion of the swinging nonsupport leg. Variation of the parameters values of ground reaction and the resulting value of the kinetic moment allowed us to synthesize the AM motion in the support phase so that it would ensure the desired trajectory of the AM motion in the flying phase of acrobatic motions. Conclusions: Research showed the necessity of employment of non-stationary constraint equations in the synthesis of complex coordination human motions. Such an approach to motion control synthesis minimizes the number of parameters to be varied and gives a relatively stable solution with respect to small variations of AM structure. REFERENCES: 1. Zinkovsky, A.V., Sholuha, V.A., Ivanov, A.A. (1997). Mathematical Modeling and Computer Simulation of Biomechanical Systems, WSP, Singapore, 216

Primary Sequences of Protein-Like Copolymers: Levy Flight Type Long Range Correlations

We consider the statistical properties of primary sequences of two-letter HP copolymers (H for hydrophobic and P for polar) designed to have water soluble globular conformations with H monomers shielded from water inside the shell of P monomers. We show, both by computer simulations and by exact analytical calculation, that for large globules and flexible polymers such sequences exhibit long-range correlations which can be described by Levy-flight statistics.Comment: 4 pages, including 2 figures; several references added, some formulations improve

Mineralogy of the inclusions and age of zircon from granite basement of Verkhnerechensk area (Yamal peninsula)

The study of minerals-prisoners in accessory zircons is gradually evolving into an important geological-petrological task. Such a study can show not only the earliest mineral rock association, but also evaluate the “sealed” mineral paragenesis of zircon, which in turn indicates whether the accessory zircon is native to the host rock or redeposited (alien). In the present work, the mineralogy of zircon from granitoids of the crystalline basement of the Verkhnerechensk oil-exploration area (the southern part of the Yamal Peninsula, Western Siberia) has been studied. Granitoids are represented by homogeneous light gray fine-grained variety of biotite-quartz-feldspar composition and refer to monzoleucogranite, which formed over the sedimentary substrate, most likely under conditions of late orogenic surrounding. The time of magmatic intrusion and crystallization of granites according to the data of U-Pb dating of zircon (measurements carried out on the ion microprobe SHRIMP-II) is estimated as Late Permian (254.0 ± 3.0 (MSWD = 1.6) Ma). It is established that inclusions in zircon are represented by various minerals - fluorapatite, titanite, monazite-(Ce), albite, quartz, chamosite and calcite. The last two minerals, apparently, were not formed together with zircon, but are later secondary minerals formed as a result of the propylization of the rock. The time of secondary changes in the granitoid supposedly occurred in the Late Triassic, as one of the zircons gave a U-Pb dating of 204.7 ± 2.6 Ma. In general, accessory zircons and mineral inclusions contained in them belong to the “granite” association, and, apparently, are native to the enclosing monzoleucogranite

Observation of linear and nonlinear light localization at the edges of moiré arrays

We observe linear and nonlinear light localization at the edges and in the corners of truncated moiré arrays created by the superposition of periodic mutually twisted at Pythagorean angles square sublattices. Experimentally exciting corner linear modes in the femtosecond-laser written moiré arrays we find drastic differences in their localization properties in comparison with the bulk excitations. We also address the impact of nonlinearity on the corner and bulk modes and experimentally observe the crossover from linear quasilocalized states to the surface solitons emerging at the higher input powers. Our results constitute the first experimental demonstration of localization phenomena induced by truncation of periodic moiré structures in photonic systems.This research is funded by the research Project No. FFUU- 2021-0003 of the Institute of Spectroscopy of the Russian Academy of Sciences and partially funded by the RSF Grant No. 21-12-00096. F. Y. acknowledges support from Shanghai Outstanding Academic Leaders Plan (Grant No. 20XD1402000) and the NSFC (Grant No. 91950120). S. K. I. and L. T. acknowledge support by Grants No. CEX2019-000910-S and No. PGC2018-097035-B-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER, Fundació Cellex, Fundació Mir-Puig, and Generalitat de Catalunya (CERCA).Peer ReviewedPostprint (published version

Robust cryogenic matched low-pass coaxial filters for quantum computing applications

Electromagnetic noise is one of the key external factors decreasing superconducting qubits coherence. Matched coaxial filters can prevent microwave and IR photons negative influence on superconducting quantum circuits. Here, we report on design and fabrication route of matched low-pass coaxial filters for noise-sensitive measurements at milliKelvin temperatures. A robust transmission coefficient with designed linear absorption (-1dB/GHz) and ultralow reflection losses less than -20 dB up to 20 GHz is achieved. We present a mathematical model for evaluating and predicting filters transmission parameters depending on their dimensions. It is experimentally approved on two filters prototypes different lengths with compound of Cu powder and Stycast commercial resin demonstrating excellent matching. The presented design and assembly route are universal for various compounds and provide high repeatability of geometrical and microwave characteristics. Finally, we demonstrate three filters with almost equal reflection and transmission characteristics in the range from 0 to 20 GHz, which is quite useful to control multiple channel superconducting quantum circuits.Comment: 5 pages, 4 figure

Gradient non-woven fabrics with a modified surface nanolayer for water filtration in construction industry

ABSTRACT: Introduction. The aim of the work is to determine the influence of the structure of the filter materials formed as a result of modification of the surface layer on their water permeability and the size of trapped solid particles. Materials and methods. The non-woven fabrics from a mixture of polyethylene-terephthalate (PET) (70 wt.%) and bicomponent fibers (BCF) of the coreshell structure were used as objects of the study. The non-woven fabrics were obtained by mechanically forming the canvas with its subsequent hardening by needle punching. The resulting materials were modified by heat treatment. The water transfer in the modified materials was determined by the permeability coefficient. The filtration efficiency was determined by the number of trapped particles of a certain size. Results and discussion. The needle-punched non-woven fabrics without additional heat treatment are not suitable for water filtration. The proposed method of thermal and deformation-thermal modification provides the production of gradient materials with a controlled thickness of the nanoscale surface layer. Although a decrease in water permeability is observed, the modified material traps solid particles with a smaller (compared to unmodified ~ 20 µm) equivalent diameter of 2–4 µm, which is sufficient to prepare water for use in steam generators and in the production of building materials. Conclusion. The optimal parameters of deformation-heat treatment for obtaining the high-effective filtration non-woven materials were established: the temperature – 180оC, the processing speed – 3.5 m/min