Full Terms Research Articles

Geophysical water flows with constant vorticity and centripetal terms

We consider here three-dimensional water flows governed by the geophysical water wave equations exhibiting full Coriolis and centripetal terms. More precisely, assuming a constant vorticity vector, we derive a family of explicit solutions, in Eulerian coordinates, to the above-mentioned equations and their boundary conditions. These solutions are the only ones under the assumption of constant vorticity. To be more specific, we show that the components of the velocity field (with respect to the rotating coordinate system) vanish. We also determine a formula for the pressure function and we show that the surface, denoted z=eta (x,y,t), is time independent, but is not flat and can be explicitly determined. We conclude our analysis by converting to the fixed inertial frame, the solutions we obtained before in the rotating frame. It is established that, in the fixed frame, the velocity field is non-vanishing and the free surface is non-flat, being explicitly determined. Moreover, the system consisting of the velocity field, the pressure and the surface defining function represents explicit and exact solutions to the three-dimensional water waves equations and their boundary conditions.

Comparison of Spin-Flip TDDFT-Based Conical Intersection Approaches with XMS-CASPT2.

Determining conical intersection geometries is of key importance to understanding the photochemical reactivity of molecules. While many small- to medium-sized molecules can be treated accurately using multireference approaches, larger molecules require a less computationally demanding approach. In this work, minimum energy crossing point conical intersection geometries for a series of molecules have been studied using spin-flip TDDFT (SF-TDDFT), within the Tamm-Dancoff Approximation, both with and without explicit calculation of nonadiabatic coupling terms, and compared with both XMS-CASPT2 and CASSCF calculated geometries. The less computationally demanding algorithms, which do not require explicit calculation of the nonadiabatic coupling terms, generally fare well with the XMS-CASPT2 reference structures, while the relative energetics are only reasonably replicated with the MECP structure as calculated with the BHHLYP functional and full nonadiabatic coupling terms. We also demonstrate that, occasionally, CASSCF structures deviate quantitatively from the XMS-CASPT2 structures, showing the importance of including dynamical correlation.

The Effectiveness of the Hijaashi Method to Reduce Aggressive Behavior in Children with Autism Spectrum Disorder in Jordan

In-Text Citation: (Abusinie & Baioumy, 2020) To Cite this Article: Abusinie, A., & Baioumy, N. (2020). The Effectiveness of the Hijaashi Method to Reduce Aggressive Behavior in Children with Autism Spectrum Disorder in Jordan. International Journal of Academic Research in Business and Social Sciences, 10(3), 183–201. Copyright: © 2020 The Author(s) Published by Human Resource Management Academic Research Society (www.hrmars.com) This article is published under the Creative Commons Attribution (CC BY 4.0) license. Anyone may reproduce, distribute, translate and create derivative works of this article (for both commercial and non-commercial purposes), subject to full attribution to the original publication and authors. The full terms of this license may be seen at: http://creativecommons.org/licences/by/4.0/legalcode Vol. 10, No. 3, 2020, Pg. 183 - 201 http://hrmars.com/index.php/pages/detail/IJARBSS JOURNAL HOMEPAGE Full Terms & Conditions of access and use can be found at http://hrmars.com/index.php/pages/detail/publication-ethics The Effectiveness of the Hijaashi Method to Reduce Aggressive Behavior in Children with Autism Spectrum Disorder in Jordan Ahmad Abusinie, Nashaat Baioumy Faculty of Islamic Contemporary Studies, University Sultan Zainal Abidin, Terengganu, MALAYSIA Abstract Children with autism spectrum disorder suffer from behavioral problems represented in aggressive behavior towards themselves and others, therefore, the child's inability to perform basic life skills, his isolation and his inability to integrate with others. As such, the present study aimed to prepare a training program based on the Hijaashi method in alleviating aggressive behavior in children with autism spectrum disorder in Jordan and verifying its effectiveness in the pre and post measurements. The present study used a quasi-experimental quantitative descriptive approach. To achieve the objectives of the study, an aggressive behavior measure consisting of 23 paragraphs was divided into two dimensions. The sample of the study consisted of (30) children with autism spectrum disorder chosen intentionally and distributed randomly to two control groups and consisted of (15) children, and experimental consisted of (15) children. Appropriate statistical analyzes were performed, such as manova, accompanying multiple variance (mancova), ancova analysis, arithmetic mean, and standard deviations. The results showed that there were statistically significant differences at the level of significance (? = 0.05) between the mean ranks of the experimental and control groups' scores on the scale of aggressive behavior in the dimensional measurement, and the presence of statistically significant differences at the level of significance (? = 0.05) between the average ranks of the experimental group on the scale of aggressive behavior in telemetry. Conclusion: The current study contributes to alleviating aggressive behavior in children with autism spectrum disorder in Jordan and developing basic life skills, increasing their effectiveness with others, avoiding isolation, introvertedness, and contributing to training specialists on how to prepare training programs that help these children to modify their behavior.

Taking Note: Justice Harry A. Blackmun's Observations from Oral Argument about Life, the Law, and the U.S. Supreme Court

Taking Note: Justice Harry A. Blackmun's Observations from Oral Argument about Life, the Law, and the U.S. Supreme Court

Collecting evidence on the use of parliamentary oversight tools: A South African case study

Background: Parliament, through its oversight function, plays a central role in holding the executive to account. In South Africa’s 2014 Defence Review policy document, it was stated that the ‘Defence Force is in a critical state of decline’. This brings about the question whether the South African Parliament effectively held the executive to account regarding developments around defence.Objectives: The article aims to gather evidence on the use of oversight tools by the South African Parliament over a 20-year period, within the post-1994 democratic dispensation, in order to determine the broader trajectory of parliamentary defence oversight.Method: To determine the trajectory of oversight, this article gathered evidence on the use of internationally recognised parliamentary oversight tools by South Africa’s two parliamentary defence committees from 1994 to 2014. The period allows for a 20-year review of oversight of defence, inclusive of four full parliamentary terms. Evidence was collected on parliamentary debates, questions, special inquiries, oversight visits and the use of external audits as oversight tools.Results: The article found that tools were used with varying degrees of success. Results for research on each oversight tool is discussed.Conclusion: Based on evidence on the use of oversight tools, this article concludes that over a 20-year period there was a declining trajectory in parliamentary oversight of the defence portfolio. The proven applicability of the criteria utilised in this article can serve to inform evaluations of the effectiveness of parliamentary oversight, specifically at committee level.

Active-sterile neutrino oscillations in the early Universe with the complete mixing matrix

In the framework of a 3+1 scheme with an additional inert state, we consider the thermalisation of sterile neutrinos in the early Universe taking into account the full 4 × 4 mixing matrix. The evolution of the neutrino energy distributions is found solving the momentum-dependent kinetic equations with full diagonal collision terms. The degree of thermalisation of the sterile state is shown in terms of the effective number of neutrinos, N eff, and its dependence on the three additional mixing angles (θ 14, θ 24, θ 34) and on the squared mass difference ∆m 2 41 is discussed. Our results are relevant for fixing the contribution of a fourth light neutrino species to the cosmological energy density, whose value is very well constrained by the final Planck analysis. For the preferred region of active-sterile mixing parameters from short-baseline neutrino experiments, we find that the fourth state is fully thermalised (N eff ≃ 4).

Backstepping-Based Estimation of Thermoacoustic Oscillations in a Rijke Tube With Experimental Validation

We investigate the state observer design problem for thermoacoustic instabilities in a Rijke tube using an infinite dimensional perspective. The observer, whose design is based on the backstepping methodology with Volterra and full integral terms, consists of a copy of the linearized plant model plus output injection terms and relies only on a single boundary acoustic pressure sensor. The exponential convergence, in the $L_{2}$ sense, of the observed error dynamics is proved, and the analytic expression of the observer gains are derived explicitly. The results are tested in an experimental Rijke tube prototype in order to illustrate the effectiveness of the method.

Statistical based hydromechanical models to estimate poroelastic effects of CO2 injection into a closed reservoir

AbstractIn this study, a statistical‐based methodology is used to evaluate the poroelastic effects of injection during CO2 geologic sequestration in a closed reservoir. We constructed a series of hydromechanical models to evaluate the poroelastic effect of injection by quantifying total stress changes inside the reservoir, reservoir displacement, and surface uplift. The models are representative of closed carbonate reef reservoirs of the Michigan basin. A combination of experimental design for seven independent parameters (depth, caprock and reservoir Young's modulus, caprock and reservoir Poisson's ratio, pressure, and Biot's coefficient) and response surface modeling was used to develop statistical‐based reduced‐order models. We performed 147 numerical simulations to develop simplified models. The poroelastic model responses were captured using a standard quadratic model with full interaction terms, as well as a reduced model with only statistically significant coefficients. The interpretation of reduced‐order models, using R2 loss method, shows that while surface uplift depends mainly on the depth of the reservoir, stress increase depends mainly on Biot's coefficient. The developed statistical‐based models provide a quick tool to evaluate the poroelastic effect of injection into the closed carbonate reservoirs of the Michigan basin. Reduced‐order models were then combined with a Monte Carlo simulation to perform poroelastic uncertainty analyses and achieve a better understanding of the poroelastic performance of CO2 storage in the closed carbonate system of the Michigan basin. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

A Backstepping-based observer for estimation of thermoacoustic oscillations in a Rijke tube with in-domain measurements

This paper presents an observer design for estimation of thermoacoustic instabilities in a Rijke tube. To study this problem, we consider that the acoustic dynamics is represented by the wave equation with a point source term representing the heat release. In turn, the heat release dynamics is given by a first-order ordinary differential equation (ODEs). The observer, whose design is based on the backstepping methodology, relies on measurements of acoustic pressure and velocity at an arbitrary point of the domain. The design employs a folding transformation (with two folds) around the measurements and the heat release point, allowing to write the system into a form with more states but boundary measurements and ODE couplings. Then, we formulate a well-posed and invertible integral transformation with both triangular and full terms that maps the observer error dynamics into an exponentially stable target system. The theoretical results were tested through numerical simulations in order to show the effectiveness of the design.

Numerical ability of hyperbolic flux solvers to compute 2D shear layers in turbulent shallow flows

Current computational power allows the modelling of complex time dependent flows. In particular, shallow water flows are frequently simulated to achieve solutions for different problems in the field of civil and environmental engineering. The mesh resolution and related computational cost are primarily associated to the scale of the flow structures to be investigated. Nonetheless, turbulence also plays an important role on computational cost since it participates in the generation, shedding and support of such flow structures. Different mathematical models can be considered to numerically simulate the turbulence of unsteady shallow flows depending on the degree of turbulent scale resolution required. Depending on the adopted approach, the level of accuracy required (i.e. the range of scales that must be resolved with a low diffusive and dispersive error) is different. Such accuracy, namely the dispersive and dissipative characteristic, is directly related with the numerical scheme used to discretize the equations. In finite volume schemes, the range of scales of turbulent motion that a numerical model can accurately resolve strongly depends on the Riemann solver used (via its intrinsic numerical diffusion), apart from the order of accuracy and degrees of freedom of the method. In this work, we aim at the analysis of two well-known Riemann solvers in the framework of the classical shallow water equations (i.e. considering the full convective terms and neglecting dissipation): the ARoe and HLLS solvers. An important difference between the ARoe and HLLS solvers is the numerical diffusion inherent to each of them. This artificial diffusion combined with the mesh resolution determine the cut-off scale resolved by each numerical technique. For this purpose, we assess the suitability of each solver by means of the analysis of the kinetic energy cascade of the numerical solution using a double shear layer configuration. This analysis is combined with the examination of the analytical expression of he approximate solution for a shear wave, provided by the aforementioned solvers. The study herein presented allows to assess whether or not all the relevant turbulent flow structures are resolved and if the phenomenon of interest is thus accurately modeled. The numerical results evidence that a diffusive profile appears at the shear line during the first steps of the simulation, determining the duration of the linear regime prior to the turbulent motion. The strength of this profile, shown to be higher for the HLLS solver, is associated to the numerical diffusion of the solver. The analysis of the energy cascade also agrees with this observation.

A continuum eight‐parameter shell finite element for large deformation analysis

In this paper, a finite element formulation, using eight independent parameters and high‐order spectral/hp functions, for nonlinear analysis is presented. This formulation allows the use of a third‐order thickness stretch kinematics, which also avoids Poisson's locking. Full nonlinear terms up to quadratic in the Green–Lagrange strain tensorare retained. Several nontrivial problems are solved using the presented formulation. A comparison between this formulation and others found in the literature,and with shell and solid elements in commercial codes ABAQUS and ANSYS are presented and the differences are brought out.

Thermalisation of sterile neutrinos in the early universe in the 3+1 scheme with full mixing matrix

In the framework of a 3+1 scheme with an additional inert state, we consider the thermalisation of sterile neutrinos in the early Universe taking into account the full 4×4 mixing matrix. The evolution of the neutrino energy distributions is found solving the momentum-dependent kinetic equations with full diagonal collision terms, as in previous analyses of flavour neutrino decoupling in the standard case. The degree of thermalisation of the sterile state is shown in terms of the effective number of neutrinos, Neff, and its dependence on the three additional mixing angles (θ14, θ24, θ34) and on the squared mass difference Δ m241 is discussed. Our results are relevant for fixing the contribution of a fourth light neutrino species to the cosmological energy density, whose value is very well constrained by the final Planck analysis. For the preferred region of active-sterile mixing parameters from short-baseline neutrino experiments, we find that the fourth state is fully thermalised (Neff≃ 4).

Neutrino quantum kinetics in compact objects

Neutrinos play a critical role of transporting energy and changing the lepton density within core-collapse supernovae and neutron star mergers. The quantum kinetic equations (QKEs) combine the effects of neutrino-matter interactions treated in classical Boltzmann transport with the neutrino flavor-changing effects treated in neutrino oscillation calculations. We present a method for extending existing neutrino interaction rates to full QKE source terms for use in numerical calculations. We demonstrate the effects of absorption and emission by nucleons and nuclei, electron scattering, electron-positron pair annihilation, nucleon-nucleon bremsstrahlung, neutrino-neutrino scattering. For the first time, we include all these collision terms self-consistently in a simulation of the full isotropic QKEs in conditions relevant to core-collapse supernovae and neutron star mergers. For our choice of parameters, the long-term evolution of the neutrino distribution function proceeds similarly with and without the oscillation term, though with measurable differences. We demonstrate that electron scattering, nucleon-nucleon bremsstrahlung processes, and four-neutrino processes dominate flavor decoherence in the protoneutron star (PNS), absorption dominates near the shock, and all of the considered processes except elastic nucleon scattering are relevant in the decoupling region. Finally, we propose an effective decoherence opacity that at most energies predicts decoherence rates to within a factor of 10 in our model PNS and within 20% outside of the PNS.

A pragmatic analysis on the types and the purposes of address terms used by the main character in Jane Austen’s “EMMA”

This research aims to describe the types of address terms used by the main character in Jane Austen’s EMMA and to reveal the main character’s purposes in using types of address terms. Further, this study employs descriptive-qualitative method. The result of the research can be concluded as follows. First, there are 8 types of address terms. They are (a) title plus last name, (b) first name, (c) full name, (d) pet name, (e) kinship terms, (f) title plus full name, (g) occupational terms, and (h) title alone. The most frequent use of address terms is title plus last name since it is used to respect the addressees. Second, there are 6 purposes of address terms. They are (a) to show politeness, (b) to show intimacy, (c) to show social status, (d) to keep inferiority, (e) to show friendship, and (f) to show solidarity. From the study, the writer found that the address terms are mostly used in purpose to be polite to the addressees. DOI: 10.26905/enjourme.v2i2.2747

The clone of K^*(n,r)-full terms

The clone of K^*(n,r)-full terms

High-order two-fluid plasma solver for direct numerical simulations of plasma flows with full transport phenomena

The two-fluid plasma equations for a single ion species, with full transport terms, including temperature and magnetic field dependent ion and electron viscous stresses and heat fluxes, frictional drag force, and ohmic heating terms, have been implemented in the CFDNS code and solved by using sixth-order non-dissipative compact finite differences for plasma flows in several different regimes. In order to be able to fully resolve all the dynamically relevant time and length scales, while maintaining computational feasibility, the assumptions of infinite speed of light and negligible electron inertia have been made. Non-dimensional analysis of the two-fluid plasma equations shows that, by varying the characteristic/background number density, length scale, temperature, and magnetic strength, the corresponding Hall, resistive, and ideal magnetohydrodynamic equations can be recovered as limiting cases. The accuracy and robustness of this two-fluid plasma solver in handling plasma flows in different regimes have been validated against four canonical problems: Alfven and whistler dispersion relations, electromagnetic plasma shock, and magnetic reconnection. For all test cases, by using physical dissipation and diffusion, with negligible numerical dissipation/diffusion, fully converged Direct Numerical Simulation (DNS)-like solutions are obtained when the ion Reynolds number based on the grid size is smaller than a threshold value which is about 2.3 in this study. For the magnetic reconnection problem, the results show that the magnetic flux saturation time and value converge when the ion and magnetic Reynolds numbers are large enough. Thus, the DNS-like results become relevant to practical problems with much larger Reynolds numbers.

Investigation on the angular displacements influence and nonlinear effects on thrust bearing dynamics

Abstract This paper presents a model of a turbocharger fixed geometry thrust bearing, considering the shaft collar axial translation and angular displacements. The work investigates the differences of a purely hydrodynamic model, modeled by Reynolds equation, and a full 3D thermo-hydrodynamic model, modeled by the generalized Reynolds equation and the 3D Energy equation, in terms of the thrust bearing supported load and restoring moments. The main point of the work is the estimate of the equivalent force and moment dynamic stiffness coefficient and the comparison of the full nonlinear terms with the linearized ones. It is shown the linearization is suitable for the restoring moments estimation, but not for the axial supported load.

Comparison between preterm and full term neonatal cord selenium in correlation to maternal serum selenium levels

BackgroundLower concentrations of selenium and glutathione peroxidase activities have been reported in pregnant women. An exposure to a high oxygen concentration at birth, an infection, inflammation, and a deficient antioxidant system make the newborn more susceptible to oxidative stress that can result in bronchopulmonary dysplasia, retinopathy of prematurity, persistent ductus arteriosus, necrotizing enterocolitis, intracranial hemorrhage, and hypoxic ischemic encephalopathy, especially in extremely low-birth-weight infants. AimThe current study aimed at the detection and comparison of maternal serum and neonatal umbilical cord selenium levels. MethodsA prospective study on 80 mothers and their healthy neonates (40 full term and 40 preterm) enrolled over the period from June to December 2016. Selenium concentrations were measured in the maternal serum and umbilical cord using a spectrophotometer. ResultsA significantly higher mean selenium level was detected in term neonates than preterm neonates (P = 0.015) with no gender difference but the difference in selenium concentration between their mothers was not significant. No significant relations found between maternal serum selenium levels and maternal age, weight, height, BMI or pregnancy weeks. The maternal serum selenium was positively correlated with the cord selenium in full-term group (r = 0.59 & P = 0.006). Significantly positive correlations between umbilical cord selenium levels in both full-term and preterm neonates with their gestational age and birth weight. ConclusionThis study indicated that cord Se concentration was different in term and preterm neonates being higher in full terms, so we recommend selenium supplementation to preterm neonates and their mothers to avoid sequelae of selenium deficiency on their health and to reach the levels obtained in full term neonates.

Interactions of azimuthal acoustic modes with an unsteady heat source in an annular duct.

The interactions of azimuthal acoustic modes with an unsteady heat source in an annular duct is studied in the present paper. Based on a linear analysis, two methods are given. One is the untruncated low order method in which the linear equations with full terms are solved. Another is the truncated low order method in which terms of order O(M) or higher are neglected, where M denotes the mean flow Mach number. From investigations, the quantities of disturbances, including reflected, transmitted acoustic waves, generated entropy waves, and vorticity waves are calculated. Results show that the amplitudes of reflected and transmitted acoustic waves dramatically depend on the temperature ratio across the heat source and the non-dimensional frequencies of incident acoustic waves. Furthermore, mean flow effects are investigated. The flow Mach number has significant effects on flow disturbances, especially on vorticity waves. Based on analytical results, the energy fluxes of disturbances are investigated. It is found that the energy flux contributed from an entropy fluctuation is much higher than the acoustic energy flux. The energy flux associated with a vortical mode becomes comparable with the acoustic energy flux only when the flow Mach number is large.

Resolvent analysis for jet noise source identification

We use resolvent analysis and spectral proper orthogonal decomposition (SPOD) to deduce the acoustic sources for an isothermal Mach 1.5 round jet. Both physics-based resolvent analysis and data-driven SPOD (using a high-fidelity, experimentally-verified, large-eddy simulation (LES) database) provide a basis for predicting the perturbation field. Singular value decomposition of the resolvent operator based upon the LES baseflow provides optimal volumetric forcing modes, or sources, and their associated linear responses. To identify physically relevant resolvent modes, comparisons are made between the highest gain responses and the highest energy SPOD modes computed directly from LES realizations. The prevalence of the associated resolvent forcing modes in the data are then assessed by projecting them onto the full LES nonlinear terms. The resulting distributions are presented and a jet noise model leveraging these forcing statistics is discussed. [This research was supported by a grant from the Office of Naval Research (Grant No. N00014- 16-1-2445). Ethan Pickering was supported by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.]