scholarly journals Analytical Estimates of Critical Taylor Number for Motion between Rotating Coaxial Cylinders Based on Theory of Stochastic Equations and Equivalence of Measures

Fluids ◽  
2021 ◽  
Vol 6 (9) ◽  
pp. 306
Author(s):  
Artur V. Dmitrenko

The purpose of this article was to present the solution for the critical Taylor number in the case of the motion between rotating coaxial cylinders based on the theory of stochastic equations of continuum laws and the equivalence of measures between random and deterministic motions. Analytical solutions are currently of special value, as the solutions obtained by modern numerical methods require verification. At present, in the scientific literature, there are no mathematical relationships connecting the critical Taylor number with the parameters of the initial disturbances in the flow. The result of the solution shows a satisfactory correspondence of the obtained analytical dependence for the critical Taylor number to the experimental data.

2021 ◽  
Vol 1 (1) ◽  
pp. 33-45
Author(s):  
Dennis McNevin ◽  
Kirsty Wright ◽  
Mark Barash ◽  
Sara Gomes ◽  
Allan Jamieson ◽  
...  

Continuous probabilistic genotyping (PG) systems are becoming the default method for calculating likelihood ratios (LRs) for competing propositions about DNA mixtures. Calculation of the LR relies on numerical methods and simultaneous probabilistic simulations of multiple variables rather than on analytical solutions alone. Some also require modelling of individual laboratory processes that give rise to electropherogram artefacts and peak height variance. For these reasons, it has been argued that any LR produced by continuous PG is unique and cannot be compared with another. We challenge this assumption and demonstrate that there are a set of conditions defining specific DNA mixtures which can produce an aspirational LR and thereby provide a measure of reproducibility for DNA profiling systems incorporating PG. Such DNA mixtures could serve as the basis for inter-laboratory comparisons, even when different STR amplification kits are employed. We propose a procedure for an inter-laboratory comparison consistent with these conditions.


Author(s):  
Carlo Cravero ◽  
Mario La Rocca ◽  
Andrea Ottonello

The use of twin scroll volutes in radial turbine for turbocharging applications has several advantages over single passage volute related to the engine matching and to the overall compactness. Twin scroll volutes are of increasing interest in power unit development but the open scientific literature on their performance and modelling is still quite limited. In the present work the performance of a twin scroll volute for a turbocharger radial turbine are investigated in some detail in a wide range of operating conditions at both full and partial admission. A CFD model for the volute have been developed and preliminary validated against experimental data available for the radial turbine. Then the numerical model has been used to generate the database of solutions that have been investigated and used to extract the performance. Different parameters and indices are introduced to describe the volute aerodynamic performance in the wide range of operating conditions chosen. The above parameters can be used for volute development or matching with a given rotor or efficiently implemented in automatic design optimization strategies.


Author(s):  
S.S. Khludkov ◽  
◽  
I.A. Prudaev ◽  
L.O. Root ◽  
O.P. Tolbanov ◽  
...  

Aluminum nitride doped with transition metal group atoms as a material for spintronics The overview of scientific literature on electric and magnetic properties of AlN doped with transition metal group atoms is presented. The review is based on literature sources published mainly in the last 10 years. The doping was carried out by different methods: during the material growth (molecular beam epitaxy, magnetron sputtering, discharge techniques) or by implantation into the material. The presented theoretical and experimental data show that AlN doped with transition metal group atoms has ferromagnetic properties at temperatures above room temperature and it is a promising material for spintronics.


Author(s):  
R. P. Srivastav

SynopsisThe methods developed in I, II of this series of papers are applied to a solution of a variety of dual series relations involving trigonometric series. In general the problem is reduced to one of solving (usually by numerical methods) a Fredholm integral equation of the second kind for an auxiliary function g(t), but for certain values of the parameters it is possible to obtain analytical solutions of the integral equations and these cases are considered in detail.


Author(s):  
Ahmadreza Eshghinejad ◽  
Mohammad Elahinia

Bending is a common mode of application and operation of shape memory alloys (SMA). So far the coupled thermomechanical behavior of these alloys have been modeled with numerical methods such as finite element. The issue in developing exact solutions for a SMA beam in bending is because of the distributed and hysteric stress-strain profile. In this paper an analytical approach is developed to find the exact solution for the displacement due to the applied force on the SMA superelastic beam. The approach is based on the assumption of linear distribution of strain along the height of a cross section in the beam. The solution is validated by experimental data and the results of the solution for a superelastic beams for different cases are illustrated.


1968 ◽  
Vol 35 (3) ◽  
pp. 571-578
Author(s):  
C. Y. Liu

Analytical solutions are obtained for the problem of boundary effects on the fully developed wake (or cavity) behind an inclined flat plate at an arbitrary angle of attack. The investigation is based on the Helmholtz free-streamline theory. Results are applied to four cases: (a) Blockage in a fixed-wall tunnel, (b) planing on a stream of finite depth, (c) planing toward a waterfall, and (d) flow over a flat plate in a bounded jet. Comparisons with linearized theory and available experimental data are made.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lorentz Jäntschi ◽  
Radu E. Sestraş ◽  
Sorana D. Bolboacă

The health benefit of drinking wine, expressed as capacity to defend the human organism from the free radicals action and thus reducing the oxidative stress, has already been demonstrated, and the results had been published in scientific literature. The aim of our study was to develop and assess a model able to estimate the antioxidant capacity (AC) of several samples of Romanian wines and to evaluate the AC dependency on the vintage (defined as the year in which wine was produced) and grape variety under presence of censored data. A contingency of two grape varieties from two different vineyards in Romania and five production years, with some missing experimental data, was used to conduct the analysis. The analysis showed that the antioxidant capacity of the investigated wines is linearly dependent on the vintage. Furthermore, an iterative algorithm was developed and applied to obtain the coefficients of the model and to estimate the missing experimental value. The contribution of wine source to the antioxidant capacity proved equal to 11%.


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