Axisymmetric Free Vibration of Layered Cylindrical Shell Filled with Fluid

The aim of the study is to analyse the axisymmetric free vibration of layered cylindrical shells filled with a quiescent fluid. The fluid is assumed to be incompressible and inviscid. The equations of axisymmetric vibrations of layered cylindrical shell filled with fluid, on the longitudinal and transverse displacement components are obtained using Love’s first approximation theory. The solutions of displacement functions are assumed in a separable form to obtain a system of coupled differential equations in terms of displacement functions. The displacement functions are approximated by Bickley-type splines. A generalized eigenvalue problem is obtained and solved numerically for a frequency parameter and an associated eigenvector of spline coefficients. Two layered shells with three different types of materials under clamped-clamped boundary conditions are considered. Parametric studies are made on the variation of the frequency parameter with respect to length-to-radius ratio and length-to-thickness ratio.

Oscillatory flow of casson fluid between parallel plates with an inclined magnetic field

The study of heat and mass transfer of oscillatory casson flow inporous medium subject to an inclined magnetic field, radiative heatflux and heat source is presented. It is supposed that Casson fluid islittle conductive and produced emf is insignificant. The solutions ofcoupled partial differential equations of velocity, temperature and con-centration profiles are found using Galerkins technique of finite elementmethod. The effect of various parameters such as Reynolds number Re,Grashoff number Gr, Solute Grashoff number Gc, Peclet number Pe,Hartman number Ha, Scmidth number Sc, Permeability parameter K,Radiative parameter R, Heat generation parameter S, Chemical reactionparameter Kr and frequency parameter w on velocity, temperature andconcentration are shown graphically and skin friction, Nusselts numberand Sherwood number are discussed by tables.

Investigating the Compatibility of IRI and ASAPS Models in Predicting the foF2 Ionospheric Parameter over the Mid Latitude Region

In this research, an investigation for the compatibility of the IRI-2016 and ASAPS international models was conducted to evaluate their accuracy in predicting the ionospheric critical frequency parameter (foF2) for the years 2009 and 2014 that represent the minimum and maximum years of solar cycle 24. The calculations of the monthly average foF2 values were performed for three different selected stations distributed over the mid-latitude region. These stations are Athens - Greece (23.7o E, 37.9 o N), El Arenosillo - Spain (-6.78 o E, 37.09 o N), and Je Ju - South Korea (124.53 o E, 33.6 o N). The calculated values using the two tested models were compared with the observed foF2 datasets for each of the three selected locations. The results showed that the two tested models gave good and close results for all selected stations compared to the observed data for the studied period of time. At the minimum solar cycle 24, the ASAPS model showed in general better values than the IRI-2016 model at Athens, El Arenosillo and Je Ju stations for all tested methods. At maximum solar cycle 24, the IRI-2016 model showed higher and closer values to the observed data at Athens and El Arenosillo stations, while the ASAPS model showed better values at Je Ju station.

An Investigational Approach for Vowels of the Salar Language Based on a Database of Speech Acoustic Parameters

According to relevant specifications, this article divides, marks, and extracts the acquired speech signals of the Salar language, and establishes the speech acoustic parameter database of the Salar language. Then, the vowels of the Salar language are analyzed and studied by using the parameter database. The vowel bitmap (average value at the beginning of words), the vowel bitmap (average value at the abdomen of words), the vowel bitmap (average value at the ending of words), and the vowel bitmap (average value) are obtained. Through the vowel bitmaps, we can observe the vowel in different positions of the word, the overall appearance of an obtuse triangle. The high vowel [i], [o], and low vowel [a] occupy three vertices, respectively. Among the three lines, [i] to [o] are the longest, [i] to [a] are the second longest, and [a] to [o] are the shortest. The lines between [a] to [o] and [a] and [i] are asymmetric. Combining with the vowel bitmap, the vowels were discretized, and the second formant (F2) frequency parameter was used as the coordinate of the X axis, and the first formant (F1) frequency was used as the coordinate of the Y axis to draw the region where the vowel was located, and then the vowel pattern was formed. These studies provide basic data and parameters for the future development of modern phonetics such as the database of Sarah language speech, speech recognition, and speech synthesis. It also provides the basic parameters of speech acoustics for the rare minority acoustic research work of the national language project.

Mathematical Modeling of Treatment Effect on Tumor Growth and Blood Flow through a Channel with Magnetic Field

In this research, we investigated the effect of tumor growth on blood flow through a micro channel by formulated the governing model with the assumption that blood is an incompressible, eclectrially conducting fluid which flow is caused by the pumping action of the heart and suction. The governing model was scaled using some dimensionless variables and the region of the tumor was obtained from Dominguez [1] which was incorporated in our model. The model is further reduced to an ordinary differential equation using a perturbation condition. However, the ordinary differential equation was solved using method of undermined coefficients, and the constants coefficients obtained via matrix method. Furthermore, the simulation to study the effect of the pertinent parameters was done suing computation software called Mathematica. It is seen in our investigation that the entering parameters such as magnetic field parameter, the Reynolds number, womersley number, oscillatory frequency parameter, and permeability parameter affect the blood velocity profile in decreasing and increasing fashion.

Dynamical similarity of multi-block catenary arches and rocking blocks subjected to horizontal base excitation

In this paper, the dynamical similarity of multi-block catenary arches and columns is discussed, which can be used for the simplified design of rocking arches. The basic hypothesis is that the dynamic response of multi-block arches and columns is similar when the shape of the arch follows the thrust line, i.e. it is a catenary arch. It is validated numerically that the responses of slender catenary arches are safe and reliable approximations of those of not slender arches and then that the overturning acceleration (response) spectra of rigid, slender monolithic blocks can be directly applied for catenary arches. The similarity is based on two parameters, on the limit peak ground acceleration (under which the structure will not move at all) and on the frequency parameter (defined by Housner for rigid blocks).

Dynamics of Race Structures of Pyricularia oryzae Populations Across 18 Seasons in Guangdong Province, China

Rice blast, caused by Pyricularia oryzae, is one of the most damaging fungal diseases affecting rice. Understanding how the pathogen’s race structure varies over time supports the efforts of rice breeders to develop improved cultivars. Here, the race structure of P. oryzae in Guangdong province, China, where rice is cropped twice per year, was assessed over 18 seasons from 1999 through 2008. The analysis was based on the reactions of a panel of seven differential Chinese cultivars to inoculation with a set of 1,248 isolates of P. oryzae in the province. The “total race frequency” parameter ranged from 14.7 to 39.7%, and the “race diversity index” ranged from 0.63 to 0.93. Twelve (ZA63, ZA31, ZA29, ZA21, ZA13, ZA9, ZB30, ZB17, ZB8, ZB2, ZC14, and ZC8) and two (ZD8 and ZD3) races were recognized as specific to indica and japonica rice types, respectively. Of the 59 distinct races identified, only two indica type races (ZC13 and ZC15) were identified as population-common, and nine indica type races (ZB1, ZB5, ZB6, ZB7, ZB13, ZB15, ZC5, ZC13, and ZC15) and one japonica type race (ZG1) were deemed to be population-dominant; the “total top two race isolate frequency” parameter ranged from 29.8 to 74.5%. On the host side, dynamics of resistance structures of the differential set were divided into three patterns: Both Tetep and Kanto 51 expressed the highest and most stable resistance, both Sifeng 43 and Lijiangxintuanheigu conveyed much lower and unstable resistance, and Zhenlong 13, Dongnong 363, and Heijiang 18 performed intermediate and seasonally dynamic resistance. Three interesting points distinguishing race structures of P. oryzae populations in southern and northeastern China were also discussed. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .